HomeMy WebLinkAboutFEMA Managing Floodplain DevelopmentFEDERAL EMERGENCY MANAGEMENT AGENCY FEMA 265/JUL Y 1995
MANAGING FLOODPLAIN DEVELOPMENT
IN
APPROXIMATE ZONE A AREAS
A GUIDE FOR OBTAINING AND DEVELOPING
BASE (100-YEAR) FLOOD ELEVATIONS
APRIL 1995
FOREWORD
This guide was developed for use by community officials, property
owners, developers, surveyors, and engineers who may need to
determine Base (100-year) Flood Elevations (BFEs) in special flood
hazard areas designated as approximate Zone A on the Federal
Emergency Management Agency's Flood Insurance Rate Maps published
as part of the National Flood Insurance Program. One of the
primary goals of this document is to provide a means of determining
BFEs at a minimal cost.
The guidance provided herein is primarily intended for use in
riverine and lake areas where flow conditions are fairly uniform,
and do not involve unusual flow regimes (rapidly varying flow, two-
dimensional flow, supercritical flow, hydraulic jumps, etc.).
This guide is not to be used for areas that experience alluvial fan
flooding or areas that contain characteristics of alluvial fan
flooding. In addition, this guide is not to be used in Zone V
(velocity) areas or coastal Zone A areas that are subject to
flooding due to storm surge from hurricanes and other coastal
storms. Furthermore, guidance on determining regulatory floodways
is not provided in this guide.
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TABLE OF CONTENTS
Page
I. INTRODUCTION . . . I-1
II. NATIONAL FLOOD INSURANCE PROGRAM BACKGROUND II-1
III. APPLICABLE NATIONAL FLOOD INSURANCE PROGRAM FLOODPLAIN
MANAGEMENT REQUIREMENTS IN APPROXIMATE ZONE A AREAS • III-1
Requirements for Obtaining Base (100-year)
IV.
v.
VI.
Flood Elevation Data • . . . . . . . . . • . III-1
Requirements for Developing Base (100-year)
Flood Elevation Data • • • • . . . . . . III-2
Use of Draft or Preliminary Flood Insurance
study Data • • • . • . • • • • . . . . . • . III-7
Advantages of Developing Base (100-year)
Flood Elevation Data . . . . . . . . . III-8
OBTAINING EXISTING BASE (100-YEAR) FLOOD
Federal Emergency Management Agency .
Other Federal Agencies . . . . . . .
Other state and Local Agencies
ELEVATIONS
DEVELOPING BASE (100-YEAR) FLOOD ELEVATIONS
simplified Methods . . .
Contour Interpolation
Data Extrapolation
Detailed Methods . . . . . . . . . . . . . . . . .
Topography . . . . . . . . . . . . . . .
Existing Topographic Maps . . . . . . . . .
Datum Requirements for Field Surveys . . .
Number of Cross Sections Required . . .
Proper Location of Cross Sections . . .
Hydrology • • . . . . • • • • . . . . • . . . • •
Discharge-Drainage Area Relationships
Regression Equations . • . . . . . . . . .
TR-5 5 • • • • • • • • • • • • • • • • • • •
Rational Formula . . . . . . . • . . . . • .
Other Hydrograph Methods . . . . . . . .
Hydraulics . . . . . . . . . . . . . . . • .
Normal Depth . . . . . . • . . . • . . . .
Critical Depth . . . . . . . . . . . . . . .
Step-Backwater Analysis . . . .
Hydraulic Structures • . . . . . . . .
OBTAINING LETTERS OF MAP CHANGE . . . . . . . . .
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IV-1
IV-1
IV-3
IV-4
V-1
. V-1
. V-2
. V-7
V-11
V-11
V-11
V-12
V-13
V-13
V-15
V-16
V-19
V-20
V-20
V-21
V-22
V-23
V-26
V-28
V-28
VI-1
FIGURES
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TABLE OF CONTENTS (contin ued)
-Flood Hazard Boundary Map . . . . . . . . . . .
-Flood Insurance Rate Map . . . . . . . . .
-Proposed 76-Lot Subdivision . . . . . . . . . .
-Proposed 6.7-Acre Subdivision ...... .
-Proposed 76-Lot Subdivision . . . .
-Proposed 5.6-Acre Subdivision ...... .
-Proposed 6.7-Acre Subdivision ........ .
-contour Interpolation Method -
II-2
II-3
III-2
III-3
III-4
III-4
III-5
Riverine Flooding Example 1 . . .
-contour Interpolation Method -
. . V-4
Riverine Flooding Example 2 . . . . . . . . . . . V-5
-contour Interpolation Method -
Lacustrine Flooding Example 3 . . . . . . . . V-6
-Data Extrapolation Method -Profile . . . . . . . V-8
-Data Extrapolation Method -Plan View . . . . V-8
-Data Extrapolation Method -Profile . V-9
-Data Extrapolation Method -Plan View . . . . . . V-9
-Data Extrapolation Method -Profile . . . . V-10
-Cross Section Orientation . . . . . . . . . . . V-14
-Locate cross sections at Points of Flood
Discharge Changes . . . . . . . . . . . . .
18 -Cross Section Locations at Structures . . . . .
19 -Wendy Run Drainage Basin . . . . . . . . . . .
20 -Discharge-Drainage Area Plot . . . . . . . . .
21 -100-Year Discharge Estimates for Site A
V-14
V-15
V-18
V-18
and Site B . . . . . . . . . . . . . . . . . . V-19
Figure 22 -Channel Bank Stations . . . . . . . . . . . . . V-25
Figure 23 -Weir Flow -Embankment Profile is Not
Horizontal . . . . . . . . . . . . . . . . . . V-30
Figure 24 -Weir Flow over Road . . . . . . . . . . . . . . V-31
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TABLE OF CONTENTS (continued)
APPENDICES
Appendix 1 -Glossary of Floodplain Analysis Terms . Al-1
Appendix 2 -Flood Insurance Study Data Request Form A2-l
Appendix 3 -Federal Emerqency Manaqement Aqency Offices
and Other Federal and State Aqencies . . . . A3-1
Appendix 4 -state Hydroloqy Reports A4-1
Appendix 5 -Manninq's "n" Values A5-1
Appendix 6 -QUICK-2 computer Proqram Manual A6-1
Appendix 7 -Hydraulic computer Manuals A7-1
Appendix 8 -Normal Depth Hand Calculations AS-1
Appendix 9 -Weir Flow Hand Calculations A9-1
Appendix 10 -Worksheet Al0-1
iv
Guide for Approximate Zone A Areas Introduction
I. INTRODUCTION
This guide is primarily intended to assist local community
officials in administering and enforcing the floodplain
management requirements of the National Flood Insurance
Program (NFIP). This document provides guidance for
determining Base {100-year) Flood Elevations (BFEs) in special
flood hazard areas that have been identified and designated as
approximate Zone A on a community's NFIP maps. Zone A
identifies an approximately studied special flood hazard area
for which no BFEs have been provided. Although BFEs are not
provided, the community is still responsible for ensuring that
new development within approximate Zone A areas is constructed
using methods that will minimize flood damages. This often
requires obtaining or calculating BFEs at a development site.
Developers, property owners, engineers, surveyors, and others
at the local level who may be required to develop BFEs for use
in approximate Zone A areas should also find this guide
useful. Included in this guide are methodologies that can be
used to develop BFEs, which can be used to determine the
elevation or floodproofing requirements for buildings. The
detailed methodologies described in this guide can also be
used to develop the BFE information necessary to obtain a
Letter of Map Amendment or a Letter of Map Revision Based on
Fill from the Federal Emergency Management Agency {FEMA) to
remove a legally defined property or structure from a special
flood hazard area. In addition, Letter of Map Revision
requesters may use the detailed methods in this document to
develop the BFE information that must be submitted to FEMA to
demonstrate that an area will not be flooded during the 100-
year flood.
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Guide For Approximate zone A Areas NFIP Backqround
II. NATIONAL FLOOD INSURANCE PROGRAM BACKGROUND
In 1968, the United States Congress passed the National Flood
Insurance Act, which created the NFIP. Congress recognized
that the success of this program required that community
participation be widespread, that studies be conducted to
accurately assess the flood risk within each participating
flood-prone community, and that insurance premium rates be
established based on the risks involved and accepted actuarial
principles. To meet these objectives, the 1968 Act called
for: 1) the identification and publication of information
within five years for all floodplain areas that have special
flood hazards; and 2) the establishment of flood-risk zones in
all such areas to be completed over a 15-year period following
the passage of the act.
Within the first year of NFIP operation, it became evident
that the time required to complete the detailed flood
insurance studies would markedly delay implementation in many
flood-prone communities. As a result, an interim means for
more rapid community participation in the NFIP had to be
provided. The Housing and Urban Development Act of 1969
expanded participation by authorizing an Emergency Program
under which insurance coverage could be provided at non-
actuarial, federally-subsidized rates in limited amounts
during the period prior to completion of a community's flood
insurance study.
Until engineering studies could be conducted for these
communities, Flood Hazard Boundary Maps, such as the one s~own
in Figure 1, "Flood Hazard Boundary Map," which· delineated··the
boundaries of the community's special flood hazard areas, were
prepared using available data or approximate methods. The
Flood Hazard Boundary Maps identified, on an approximate
basis, the areas within a community subject to inundation by
the 100-year flood {i.e., Zone A). The 100-year flood has a
one-percent chance of being equalled or exceeded in any given
year. The Flood Hazard Boundary Map was intended to assist
communities in managing floodplain development, and insurance
agents and property owners in identifying those areas where
the purchase of flood insurance was advisable.
The Flood Disaster Protection Act of 1973, which also amended
the 1968 Act, required that flood-prone communities be
notified of their flood hazards to encourage program
participation. This notification was accomplished through the
publication of Flood Hazard Boundary Maps for all communities
that were identified as containing flood hazard areas. In
addition, the 1973 Act required the purchase of flood
insurance by property owners who were being assisted by
II-1
Guide For Approximate zone A Areas NFIP Background
Figure 1 -Flood Hazard Boundary Map
Federal programs, or by Federally supervised, regulated, or
insured agencies or institutions, in the acquisition or
improvement of land or facilities located, or to be located,
in special flood hazard areas. This act also severely limited
Federal financial assistance in the flood hazard areas of
communities which did not join the NFIP.
The initial Flood Hazard Boundary Maps for communities
identified as having flood hazards were prepared using
available floodplain data contained in reports developed by a
variety of Federal, State, and local sources. For those
communities that had no available flood information,
approximate hydrologic and hydraulic methods or historical
flood data were used to determine the extent of the special
flood hazard areas.
Flood I nsurance studies that used detailed hydrologic and
hydraulic analyses to develop BFEs and designate f loodways and
risk zones were subsequently developed for most NFIP
communities. The results of a Flood Insurance study were
II-2
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Guide For Approximate Zone A Areas NFI P Background
i ssued to the community i n the f orm of a Flood Insurance Rate
Map (FIRM) , such as the one shown i n F i gure 2, "Flood
Insurance Rate Map," and, in most cases, a Fl ood Boundary and
Floodway Map and a Flood Insurance study report. Once more
detailed risk data were provided, the commun ity could enter
the Regular Program whereby more comprehens ive floodplain
management requirements were imposed and h i gher amounts of
insurance could be purchased by owners of struc t ures.
ZONE A
Figure 2 -Flood Insurance Rate Map
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1 ' FIRM
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As early as 1976, FEMA recognized that some commu nities did
not require a detailed Flood Insurance Study becau se there
were few existing buildings in the floodplain and minimal
development pressure. Shortly thereafter, F EMA began
utilizing a special conversion process whereby communities
II-3
Guide For Approximate Zone A Areas NFIP Background
were converted to the Regular Program without a Flood
Insurance Study. Consequently, these communities were
converted using FIRMs in which all of the special flood hazard
areas were designated as approximate Zone A, without BFEs.
Althoug h over 10,000 communities have now been provided
detailed Flood Insurance Studies and issued FIRMs that include
BFEs, many floodplains are still designated as approximate
Zone A without BFEs. Due to the costs of developing detailed
risk data, areas not subject to development pressure are
studied using approximate methodologies and continue to be
shown on the FIRM as approximate Zone A areas. FEMA only
provides BFEs for the floodplains of those flooding sources
that a r e currently subject to development pressure or are
projected at the initiat.ion of a Flood Insurance study or
Flood I nsurance Study restudy to be subject to development
pressure during the immediate future. Generally, a planning
period of approximately five years is used. Even in these
cases, BFEs are provided on a priority basis due to funding
constra ints. The community plays a major part in the
determination of the level of detail required in the study of
selected streams. As a result, most communities will have
FIRMs t hat include special flood hazard areas for flooding
sources that have been studied in detail with BFEs and special
flood hazard areas for flooding sources that have been studied
using approximate methods, and have been designated as
approximate Zone A.
II-4
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Guide For Approximate Zone A Areas Floodplain Management
m. APPLICABLE NATIONAL FLOOD
FLOODPLAIN MANAGEMENT
APPROXIMATE ZONE A AREAS
INSURANCE PROGRAM
REQUIREMENTS IN
The primary requirement for community participation in the
NFIP is the adoption and enforcement of floodplain management
regulations that meet the minimum standards of the NFIP
regulations in Title 44 of the Code of Federal Regulations
(CFR) Section 60. 3. These minimum standards vary depending on
the type of flood risk data provided to the community by FEMA.
The intent of floodplain management regulations is to minimize
the potential for flood damages to new construction and to
avoid aggravating existing flood hazard conditions that could
increase potential flood damages to existing structures. To
protect structures in riverine and lacustrine areas, the NFIP
regulations require that the lowest floor (including basement)
of all new construction and substantial improvements of
residential structures be elevated to or above the BFE. New
or substantially improved non-residential structures in
riverine areas must either be elevated or floodproofed (made
watertight) to or above the BFE.
Requirements for Obtaining BFE Data
In areas designated as approximate Zone A, where BFEs have not
been provided by FEMA, communities must apply the provisions
of Paragraph 60.3(b) of the NFIP regulations. Subparagraph
60.3(b) (4) requires that communities:
Obtain, review and reasonably utilize any
base flood elevation and f loodway data
available from a Federal, State, or other
source . . . ( 4 4 CFR 6 o . 3 ( b) ( 4) )
Section IV describes the sources from which BFE data may be
obtained. These data are to be used as criteria for requiring
that new construction, substantial improvements, and other
development within all approximate Zone A areas meet the
applicable requirements in Paragraphs 60.3(c) and (d) of the
NFIP regulations, including the requirement that structures
have their lowest floors elevated to or above the BFE (or
f loodproof ed to or above the BFE for non-residential
structures). These data should be used as long as they
reasonably reflect flooding conditions expected during the
base (100-year) flood, are not known to be scientifically or
technically incorrect, and represent the best data available.
Communities should consider formally adopting these data by
reference as part of their floodplain management regulations.
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Guide For Approximate Zone A Areas Floodplain Management
Requirements for Developing BFE Data
Under Subparagraph 60.3(b) (3) of the NFIP regulations,
communities must also:
Require that all new subdivision proposals
and other proposed development (including
proposals for manufactured home parks and
subdivisions) greater than 50 lots or 5
acres, whichever is the lesser, include
within such proposals base flood elevation
data ; [ 4 4 CFR 6 0 . 3 ( b) ( 3 ) ]
This means that any subdivision which meets this threshold
must be evaluated to determine if the subdivision proposal is
affected by an approximate Zone A area and whether BFE data
are required. BFE data are required for the affected lots in
the s u bdivisions shown in Figure 3, "Proposed 76-Lot
Subdivision," and Figure 4, "Proposed 6.7-Acre Subdivision."
Figure 3 clearly shows a 76-lot subdivision with several lots
affected by an approximate Zone A area. The subdivision
depicted in Figure 4 is only 12 lots, but because the
subdivision is greater than 5 acres and clearly shows
buildable sites affected by an approximate Zone A area, BFE
data are required.
Figure 3 -Proposed 76-Lot Subdivision
III-2
Guide For Approximate zone A Areas Floodplain Manaqement
Figure 4 -Proposed 6.7-Acre Subdivision
Communities are encouraged to address the flood hazards at the
earliest stages of subdivision planning rather than at the
actual placement of individual structures. If a community can
work with the developer and others when land is being
subdivided, many long-term floodplain management benefits can
be achieved, particularly if the floodplain is avoided
altogether. In Figure 5, "Proposed 76-Lot Subdivision," the
entire approximate Zone A area is to be dedicated as open
space. If the planned subdivision shows the floodplain is
contained entirely within an open space lot, it may not be
necessary to conduct a detailed engineering analysis to
develop BFE data.
Also, it may not be necessary to develop detailed BFE data in
large-lot subdivisions or single-lot subdivisions that are
within the thresholds under Subparagraph 60.3(b) (3) of the.
NFIP regulations when the actual building sites are clearly
outside of the Zone A area. In Figure 6, "Proposed 5.6-Acre
Subdivision," it is evident from the topographic features of
this 5.6-acre subdivision that the building sites would be
clearly out of the floodplain since the proposal indicates a
steep grade between the approximate Zone A area and the
building sites which are located on natural high ground.
III-3
Guide For Approximate zone A Areas Floodplain Management
-~-1 --------.. ~
Figure 5 -Proposed 76-Lot Subdivision
Figure 6 -Proposed 5.6-Acre Subdivision
III-4
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Guide For Approximate Zone A Areas Floodplain Management
If the grade between the actual building sites and the
approximate Zone A area of the proposed subdivision is
relatively gradual, as shown in Figure 7, "Proposed 6.7-Acre
Subdivision," the floodplain could extend beyond what is shown
on the Flood Insurance Rate Map. It is very likely that
flooding could affect the building sites. In this case, an
analysis should be conducted to determine the location of the
100-year floodplain and the BFE.
Figure 7 -Proposed 6.7-Acre Subdivision
For developments that exceed the thresholds identified in NFIP
regulations Subparagraph 60.3(b) (3), BFEs must be either
obtained from other sources or developed using detailed
methodologies comparable to those contained in a Flood
Insurance Study. Section V describes some of the detailed
methodologies available that can be used to develop BFE data
when none are available from the sources listed in Section IV.
If the size of the new subdivision or other proposed
development falls below the thresholds -specified in NFIP
regulations Subparagraph 60.3(b) (3) and no BFE data are
available from the sources listed in Section IV, the community
must still apply, at a minimum, the requirements of
Subparagraph 60. 3 (a) ( 3) to proposed structures or Subparagraph
60.3(a) (4) to subdivisions and other developments within
approximate Zone A areas. These paragraphs require that
permit officials:
III-5
Guide For Approximate Zone A Areas Floodplain Manaqement
Review all permit applications to determine whether
proposed building sites will be reasonably safe from
flooding. If a proposed building site is in a flood-
prone area, all new construction and substantial
improvements shall (i) be designed (or modified) and
adequately anchored to prevent floatation, collapse, or
lateral movement ... , (ii) be constructed with materials
resistant to flood damage, (iii) be constructed by
methods and practices that minimize flood damages, and
(iv) be constructed with electrical, heating,
ventilation, plumbing, and other service facilities that
are designed and/or located so as to prevent water from
entering or accumulating within the components during
conditions of flooding. [ 44 CFR 60. 3 (a) ( 3) ]
Review subdivision proposals ... including manufactured
home parks or subdivisions ... to assure that (i) all
such proposals are consistent with the need to minimize
flood damage within the flood-prone area, (ii) all
public utilities and facilities .•. are located and
constructed to minimize or eliminate flood damage, and
(iii) adequate drainage is provided to reduce exposure
to flood hazards; [44 CFR 60.3(a) (4)]
One way that communities can ensure that building sites will
be reasonably safe from flooding for proposed developments
that fall below the thresholds in Subparagraph 60.3(b) (3) is
to use the simplified methods outlined in Section V for
estimating a BFE. Another approach to ensure that a building
site is reasonably safe from flooding is to require the
structure to be elevated above the highest adjacent grade by
a specified number ·of feet based on the local official's
knowledge of flood conditions in the area. In the absense of
available BFE data from other sources, the community may
require the permit applicant to elevate the structure two or
more feet above the highest adjacant grade which qualifies the
structure for reduced flood insurance rates. Elevation of the
structure to four feet above the highest adjacant grade will
enable the structure to qualify for substantially reduced
flood insurance rates.
However, some states and communities require that BFE data be
developed for all subdivisions and/or floodplain development
within approximate Zone A areas, not just those subdivisions
which meet the 50-lot or 5-acre threshold. A community may,
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Guide For Approximate Zone A Areas Floodplain Manaqement
at its discretion, require the use of detailed methods for
such development. While this requirement is more restrictive
than NFIP minimum requirements, the NFIP regulations
specifically recognize and encourage states and communities to
adopt and enforce more restrictive floodplain management
regulations in those instances where the state or community
believes that it is in the best interest of its citizens.
No matter what the size of the subdivision or otn~r
development proposal, requests to revise or amend effective
Flood Insurance study information through the procedures
outlined in Part 65 and Part 70 of the NFIP regulations must
be based on detailed methodologies presented in Section V or
other methodologies comparable to those found in a Flood
Insurance Study. The analysis used to develop the BFEs must
be certified by a registered professional engineer or licen~ed
land surveyor, as appropriate, if the BFEs are to be used .to
revise or amend an NFIP map.
Use of Draft or Preliminary Flood Insurance study Data
The data from a draft or preliminary flood insurance study
constitutes "available data" under Subparagraph 60.3(b)(4).
Communities must reasonably utilize the draft or preliminary
flood insurance study data under the section of their
ordinance that requires the use of other base flood data when
detailed BFE data has not been published in a flood insurance
study. Communities are given discretion in using draft or
preliminary flood insurance study data only to the extent that
the technical or scientific validity of the proposed flood
elevation data is questioned. If a community decides not to
use the draft or preliminary flood insurance data in a FIS
because it is questioning the data through a valid appeal, the
community must still assure that buildings are constructed
using methods and practices that minimize flood damages in
accordance with the requirements under Subparagraphs
6 o. 3 (a) ( 3) and ( 4) .
When all appeals have been resolved and a notice of · final
flood elevations has been provided by FEMA, communities are
required to use the data from the flood insurance study for
regulating floodplain development in accordance with
Subparagraph 60. 3 (b) ( 4) since the data represents the best
data available. Communities must regulate floodplain
development using the flood insurance study data under
Subparagraph 60.3(b) (4) until such time as the community has
adopted the effective FIRM and flood insurance study .
III-7
Guide For Approximate Zone A Areas Floodplain Management
Advantages of Developing BFE Data
While the NFIP regulations do not require that communities
develop BFE data in approximate Zone A areas when proposed
development is below the thresholds in NFIP regulations
Subparagraph 60.3{b) (3), there are significant advantages and
financial benefits for communities and individual property
owners that develop BFE data. These advantages and benefits
include:
• protecting structures up to the BFE will minimize and
reduce future flood losses, resulting in long-term
savings to the individual, the community, and the
National Flood Insurance Fund;
• flood insurance policies in approximate Zone A areas that
are rated using a BFE will often qualify for
significantly lower insurance rates than policies that
are rated without a BFE. The difference in flood
i n surance premiums could be substantial;
• less burden will be placed on the permit official because
he or she can require protection to a specified
elevation. Without a BFE, the permit official mus.t make
j u dgements as to what constitutes "reasonably safe from
flooding" and "constructed with materials and practices
t h at minimize flood damages";
• the NFIP'.s Community Rating System establishes flood
insurance premium discounts of up to 45 percent for
policy holders within communities that have a floodplain
ma nagement program that exceeds NFIP minimum
requirements. Sizable Community Rating System credits
are available for Community Rating System communities
that develop BFEs for areas designated as approximate
Zone A on their Flood Hazard Boundary Map or FIRM, or
that require site-specific engineering analyses for
development proposals; and
• b y specifying a BFE in an approximate Zone A area, a
building or property can, in some circumstances, be
removed from the floodplain by issuance of a Letter of
Map Amendment or Letter of Map Revision in accordance
with Part 65 and Part 70 of the NFIP regulations. While
t h ese procedures eliminate the requirement that :f'lood
i n surance be purchased as a condition o:f obtaining a loan
:fr om a Federally insured or regulated lender, a lending
i n stitution may, at its discretion, require the purchase
o:f :flood insurance.
III-8
Guide For Approximate Zone A Areas Obtaining BFEs
IV. OBTAINING EXISTING BASE (100-YEAR) FLOOD ELEVATIONS
The NFIP Regulations at 44 CFR 60.3 require that structures be
elevated or floodproofed (non-residential structures only) to
provide protection from flood damage. A BFE must be
established before such flood protection measures can be used.
There are a variety of computational methods that can be
employed to determine BFEs. However, these methods can be
costly. Before computational methods are used, every attempt
should be made to obtain information, in the f orm of
floodplain studies or computations, from Federal, State, or
local agencies. Data obtained from these agencies may be
adequate to determine BFEs with little or no additional
research, computation, or cost.
Local officials who obtain BFE data should maintain the
information for future reference. Local officials should also
consider making a search for BFE data for the entire
community. By doing so, the local officials may not have to
conduct a search each time a floodplain development permit is
requested. If the data reasonably reflect flooding
conditions, a community should consider adopting the
information into its floodplain management ordinance.
Provided below are a list of agencies that can be contacted to
determine if any BFE data have already been developed. When
obtained, these data should be evaluated to ensure that they
reasonably reflect flooding conditions expected at the site
during the 100-year flood, are scientif i cally or technically
correct, and represent the best data ava i lable .
Three major sources of existing data are highlighted in this
section: FEMA, other Federal agencies, and State and local
agencies.
FEMA' s technical evaluation contractors maintain l ibraries
that contain technical and administrative data developed
during the preparation of Flood Insurance Studies, as well as
the resulting Flood Insurance Study reports and NFIP maps.
FEMA can be contacted to determine whether or not sufficient
information exists in the back-up data to calculate BFEs. For
some flooding sources that are designated as approximate Zone
A, FEMA may have detailed flooding information that has not
yet been incorporated into the community's Flood Insurance
Study. FEMA can be contacted to obtain this information where
it exists.
IV-1
Guide For Approximate Zone A Areas Obtaining BFEs
FEMA regularly conducts restudies of flood hazards in an
effort to keep Flood Insurance Studies accurate and up-to-
date. As part of these restudies, detailed BFE data for
approximate Zone A areas may be developed. During the time
that elapses between FEMA obtaining restudy data and the
incorporation of BFE data areas into a revised Flood Insurance
Study, a community may reasonably use the BFE data from the
restudy in approximate Zone A areas in accordance with
Subparagraph 60.3{b) (4).
In addition, flooding sources restudied by FEMA may often
impact several communities. FEMA may be unable to immediately
update the Flood Insurance Study for every community impacted
due to funding constraints. Therefore, BFEs may have been
developed for streams within a community that have not yet
been incorporated into the Flood Insurance Study.
It is also possible that a previous request to revise flood
hazards along a stream or lake may be on file with FEMA, and
that BFEs, which may be applicable to other areas of the same
stream or lake, may have been computed for that request.
FEMA data should be sought when trying to obtain or determine
BFEs for an approximate Zone A area, so that if BFEs have
already been determined for an approximate Zone A area, then
other BFE determinations in the same area can be based on the
same methodology. However, if it is determined that a more
scientifically or technically accurate determination than that
which is available in FEMA's back-up data is warranted, then
a more detailed methodology, such as those described in
Section V, should be utilized.
Data requests should be directed to the appropriate FEMA
technical evaluation contractor at the address listed on the
following page:
IV-2
Guide For Approximate Zone A Areas
FEMA Regions I-V
(States East of the Mississippi
River and Minnesota)
Obtaininq Bl'Bs
Flood Insurance Information Specialist
c/o Dewberry & Davis
2953 Prosperity Avenue
Fairfax, Virginia 22031
FAX: (703) 876-0073
Phone: (703) 876-0148
FEMA Regions VI-X
(States West of the
Mississippi River)
FEMA Project Library
c/o Michael Baker, Jr., Inc.
3601 Eisenhower Avenue
Suite 600
Alexandria, Virginia 22304
FAX: (703) 960-9125
Phone: (703) 960-8800
An instruction sheet entitled Flood Insurance Study CFIS) Data
Reguests is provided in Appendix 2. This sheet contains
pertinent information and instructions for requesting Flood
Insurance Study data.
A fee is charged for locating, retrieving, copying, and
mailing Flood Insurance study back-up data based on the cost
of materials and a standard hourly rate for time spent to fill
the request. FEMA will inform the requestor if the requested
data are available and of the required fee. The requestor
should allow two to four weeks for the request to be
processed.
Other Federal Agencies
Information regarding BFEs may be obtained from other Federal
agencies involved in floodplain management. A fee may be
required to obtain some of the products or services available
through these agencies. The following is a list of some of
the Federal Agencies involved in floodplain management and the
information, which may be useful in obtaining and deter~ining
BFEs, that they produce.
IV-3
Guide For Approximate zone A Areas
AGENCY
U.S. Army Corps
of Engineers
U.S. Department of the
Interior, Geological
Survey
U.S. Department of
Agriculture, Natural
Resources Conservation
Service (NRCS)
U.S. Department of
Transportation, Federal
Highway Administration
U.S. Department of Commerce
National Technical
Information, Service
Tennessee Valley Authority
Other state and Local Agencies
Obtaininq BFEs
PRODUCT
Floodplain Information
Reports
Technical Manuals
Computer Programs
Computational Assistance
Topographic Maps
Water Resource
Investigations
Technical Bulletins
Water Supply Papers
Computer Programs
Watershed Studies
Technical Releases
Computer Programs
Floodplain Studies
Design Manuals
Computer Programs
Design Manuals
Computer Programs
Floodplain Studies
If back-up data from Federal agencies are unavailable or are
not useful, information regarding BFEs may be obtained from
state or local agencies involved in floodplain management. On
the following page is a list of State and local agencies
involved in floodplain management that may be contacted to
obtain BFE information. Again, fees may be applicable for
this information.
For example, some state agencies, such as a Department of
Natural Resources or a Geological Survey, may conduct
floodplain studies using state funds. In some states, these
agencies may maintain a repository for flood data. The NFIP
state coordinating agency can also be contacted. A list of
the State coordinating agencies is provided in Appendix 3.
otner state agencies, such as a Department of Transportation,
do engineering for specific types of projects, such as road
IV-4
f
I
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Guide For Approximate Zone A Areas Obtaining BFEs
a nd bridge construction, in which BFE data may have been
developed for these projects. In general, when ca lling these
agencies, the caller should ask for a copy of any back-up data
{reports, computations, computer models, maps) assoc iated with
a FLOODPLAIN STUDY or DRAINAGE STUDY, for the area of the
particular stream of interest. In addition, some state
agencies, such as a Department of Natural Resources, may
maintain historic lake level data.
The local public works department or the local transportation
department may have developed flood data in designing sewer
and storm drainage systems and local roads. For example,
plans for a sanitary sewer line which runs paral lel to the
stream and area of interest may have 100-year flood elevations
on the profile of the sanitary sewer. Also, if there are
culverts or bridges which cross the same stream within 1,000
feet of the area of interest, there may be hydro l o gic and
hydraulic information pertaini ng to the 100-year flood
discharge and elevation which may be pertinent to the site.
Finally, if there are any nearby residential or commercial
developments along the same stream, the development {site)
plans for these projects may also include information about
the 1 00-year flood.
Other possible sources of data include regional organ i z ations,
such as Flood Control Districts, Levee Improvement Districts,
Watershed Districts, or Soil and Water Conservation Di stricts.
These organizations may have developed flood prof i les for
smaller streams or for reaches of streams impacted b y flood
contro l or drainage projects.
state Agencies:
Departments of Environmental Conservation
Departments of Environmental Protection
Departments of Floodplain Management
Departments of Natural Resources
Departments of Transportat i on
Departments of Water Resources
Geolog i cal Survey
Local or Regional Agencies:
Flood Control Districts
Levee Improvement Districts
Local Planning Commissions
Local Public Works Departments
Mun i cipa l Utility Districts
River Basin Commissions
Water Control Boards
A part i al list of Federal and State agencies is provided in
Append i x 3.
IV-5
Guide For Approximate Zone A Areas Developing BFEs
v. DEVELOPING BASE (100-YEAR) FLOOD ELEVATIONS
If sufficient BFE information cannot be obtained from the
sources described in Section IV, then the community should
consider conducting, or requiring the applicant to conduct, a
site specific engineering analysis to determine a BFE. This
section describes several simplified and detailed methods for
estimating or developing BFE data, and provides guidance for
using them.
As noted in Section III, a detailed method is required under
Subparagraph 60.3(b) (3) of the NFIP regulations for proposed
development greater than 50 lots or 5 acres, whichever is the
lesser. If the BFEs developed will be used to revise or amend
NFIP maps, they must be developed using the detailed
methodologies described in this section or other methods
comparable to those in a Flood Insurance Study.
If no BFE data are available and the proposed development is
below the thresholds specified in Subparagraph 60.3(b) (3) of
the NFIP regulations, the simplified methods for estimating
BFEs described in the following section may be used.
Simplified methods are less expensive and less time consuming
than the detailed methods described later in this section.
However, communities have the discretion to determine which
method should be used when a proposed development is below the
aforementioned thresholds.
Simplified Methods
There are situations in which a simplified approach for
estimating the BFE may yield an acceptable level of accuracy.
For simplified methods to be used, very specific conditions
must be met as discussed below.
Simplified methods are appropriate for floodplain management
purposes only. These methods may be used for the purpose of
meeting the requirements of NFIP regulations Subparagraphs
60.3(a) (3) and 60.3(a) (4) for developments, such as isolated
small subdivisions in rural areas which are below the
threshold in Subparagraph 60.3(b) (3), or single lots.
Subparagraphs 60.3(a) (3) and 60.3(a) (4) require the community
to determine whether proposed building sites are reasonably
safe from flooding and ensuring that subdivision proposals are
consistent with the need to minimize flood damage within
flood-prone areas.
V-1
Guide For Approximate Zone A Areas Developing BFEs
Simplified methods may not be used by the community to
complete an Elevation certificate used for flood insurance
rating. communities must use the detailed methodologies
described in this section or other methods comparable to those
in a Flood Insurance study for completing the Elevation
Certif i cate. A flood insurance policy for a structure for
which a simplified method is used may be rated without an
elevat i on certificate. However, the flood insurance rate may
be higher than if the structure is rated using an Elevation
Certificate.
contour Interpolation
Contour interpolat i on involves superimposing approximate Zone
A boundaries onto a topographic map in order to estimate a
BFE. BFEs obtained by this method can only be assumed to be
as accurate as one-half of the contour interval of the
topographic map that is used. Therefore, the smaller the
contour interva l of the topographic map, the higher the
accuracy of the BFE determined from the map. The procedures
for using this method are outlined below. Steps 1 through 5
are the same for both riverine and lacustrine (lake) flooding
sources.
Step 1 -Obtain a topographic map showing the site being
analyzed
Step 2 -Reduce or enlarge the FIRM or topographic map as
necessary so that the two are at the same scale
Step 3 -Superimpose the approximate Zone A (100-year)
floodplain boundary from the FIRM onto the
topographic map
step 4 -Determine if this method is within the acceptable
accuracy limits. The floodplain boundary must
general l y conform with the contour lines along the
flooding source in question. The difference
between the water-surface elevations determined on
the right overbank and the left overbank must be
within one-half of the map contour interval. For
lacustrine flooding sources, the difference between
the highest and lowest determined water-surface
elevations around the flooding source must be
within one-half of the map contour interval.
Otherwise, this method is not acceptable.
step 5 -If the method is acceptable, then determine the
BFE. Detailed guidance for determining the BFE is
provided below .
V-2
•
J
l
• I
t
Guide For Approximate zone A Areas Developinq BFEs
Determininq BFEs for Riverine floodinq:
On each side of the stream in the vicinity of the site,
determine the ground elevation at which the superimposed Zone
A boundary lies by interpolating between two contour lines.
Add one-half of the map contour interval to the lower of the
two interpolated elevations. This is the approximate BFE for
the site (be sure to perform this method at each structure
location).
By adding one-half of the contour interval to the lowest
interpolated water-surf ace elevation, two things are achieved:
1) the final BFE is within one-half of the contour interval of
both interpolated water-surface elevations and, therefore, is
still within the acceptable tolerance of the topographic map
(generally regarded as ± one-half of the map contour
interval); 2) it is a conservative estimate of the BFE. If
the BFE determined under this procedure seems too high, then
a detailed analysis may be performed to justify lowering it.
Example 1
Using a county topographic map with a contour interval of
5 feet, the approximate Zone A boundary crosses contour
elevations on the left and right bank at 323 and 325
feet, respectively, as shown in Figure 8, "Contour
Interpolation Method -Riverine Flooding Example 1." The
difference between these two water-surf ace elevations is
2 feet, which is less than one-half of the contour
interval or 2.5 feet. Therefore, this method is
acceptable for use on this portion of the stream. Add
323 feet (lowest interpolated water-surface elevation)
plus 2.5 feet (one-half of the contour interval), which
yields a BFE of 325.5.
V-3
Guide Por Approximate Zone A Areas Developing BFEs
Figure 8 -Contour Interpolation Method -
Riverine Flooding Example 1
Example 2
Using a U.S. Geological Survey quadrangle map with a
contour interval of 10 feet, the approximate Zone A
boundary crosses contour elevations on the left and right
bank of 422 and 430 feet, respectively, as shown in
Figure 9, "Contour Interpolation Method Riverine
Flooding Example 2.11 The difference between these two
water-surface elevations is 8 feet, which is greater than
one-half of the contour interval or 5 feet. Therefore,
this method is not acceptable for use on this portion of
the stream, and another method must be used to determine
t he BFE.
V-4
Guide Por Approximate zone A Areas Developing BFEs
Figure 9 -Contour Interpolation Method -
Riverine Flooding Example 2
Determining BFEs for Lacustrine (Lake) flooding:
Determine the contour elevations that the approximate Zone A
boundary crosses {i.e. the BFE) around the perimeter of the
lake or ponding area. Assuming that the highest and lowest
determined water-surface elevations are within one-half of the
map contour interval of each other, add one-half of the map
contour interval to the lowest water-surface elevation to
determine the BFE for the site.
Example 3
Using a U. s. Geological survey quadrangle map with a
contour interval of 10 feet, the approximate Zone A
boundary crosses low and high determined water-surf ace
elevations along the perimeter of the ponding area of 280
and 283 feet, respectively, as shown in Figure 10,
"Contour Interpolation Method Lacustrine Flooding
Example 3." The difference between these two water-
surface elevations is 3 feet, which is less than one-half
of the contour interval or 5 feet. Therefore, this
method is acceptable for use on this ponding area. Add
280 feet {lowest water-surface elevation) and 5 feet
{one-half of the contour interval), which yields a BFE of
285 feet.
V-5
Guide For Approximate Zone A Areas Developinq BFEs
Figure 10 -contour Interpolation Method -
Lacustrine Flooding Example 3
V-6
J
Guide For Approximate Zone A Areas Developing BFEs
Data Extrapolation
If a site is within 500 feet upstream of a stream reach for
which a 100-year flood profile has been computed by detailed
methods, and the floodplain and channel bottom slope
characteristics are relatively similar to the downstream
reaches, data extrapolation may be used to determine the BFE.
The stream in the vicinity of the site, however, must be free
of backwater effects from downstream hydraulic structures.
The procedure for using this method is outlined below.
Step 1 -Determine the location of the site on the flood
profile for the detailed study stream
Step 2 -Extrapolate the last segment of the 100-year flood
profile that has a constant water-surface slope to
the location of the site. The BFE at the site can
then be obtained directly from the profile
Figures 11-12 on the following pages depict situations (i.e.,
properties "Y" and "Z") , in which the data extrapolation
method may and may not be used. Figures 13-14 depict a
situation in which the data extrapolation method may not be
used because the highway may have an effect on the 100-year
water-surface elevations. If the 100-year flood profile
changes just prior to the limit of detailed study, as shown in
Figure 15, the data extrapolation method should not be used.
V-7
0 > Cl
6
I-w w
LI..
~
z
0
~ > w
-' w
Guide For Approximate Zone A Areas Developing BFEs
40
35
30
25
20
800
1"=400'
1--• ---500·-----•I
40
~
-35
~ r-
-'~ ..
~---I• -I• -II 30
-,_
~-
I
11 • 25
LEGEND
I J
---500-YEAR FLOOD
; -• -100-YEAR FLOOD
1 • •
I• ~STREAM BED
1000 1200 1400 1600 1800 2000 2200
STREAM DISTANCE IN FEET ABOVE THE CORPORATE LIMITS
Figure 11 -Data Extrapolation Method -Profile
,.....---"""'\-
/ < ------
/ZONE AE ?5
-~ -(------
~
'Z :Q
~ ,..,-------
N t /
al ;::;/ >-0 ::::>
: !;{
I _J
10
I Q..
I c(
I a:
)-----
400 FEET
~
0 w
-' ~ w
0
LI..
0
I-
~
:J
I 1-
1 x •w
I
·~ ':;,( :o
I LI.. :a
I I-
~ ~
I :J
I
-Property Y is approximately 370' upstream of
the limit of detailed study (as measured along
the streamline). Using the profile below, we can
extrapolate the 100-year flood profile to determine
that the BFE for property Y is equal to 33'.
Figure 12 -Data Extrapolation
Method -Plan View
-Property Z is approximately 700' upstream of
the limit of detailed study (as measured along
the streamline), and is therefore beyond the limit
of data extrapolation.
V-8
Guide For Approximate Zone A Areas Developing BFEs
0 > C!' e
I-w w u.
~
z
0
~ > w
..J w
1000
95
90 --
85
80
1500
--
1"=1000'
f+--500·-.j
~ , .. ..
---J • ,
-;
LEGEND
--500-YEAR FLOOD
- --100-YEAR FLOOD
~STREAM BED
2000 2500 3000 3500 4000 4500
STREAM DISTANCE IN FEET ABOVE THE CORPORATE LIMITS
Figure 13 -Data Extrapolation Method -Profile
~
g \, / -r-ttE=J.------
_ ... --L ____ ... / i5 :
~ en
u. [ij
0-'
t:: ~ ~UJ
-JQ
95
90
85
5000
SCALE
0 1000 FEET -State Route 27 may have an effect on the 100-year
water-surface elevations. Therefore, data extrapolation
should not be used to obtain a BFE for property R.
Figure 14 -Data Extrapolation Method -Plan View
V-9
Guide For Approximate zone A Areas Developinq BFEs
215
c 210
~
~
..... w w u.
~
z
0
~ > w
...J
205
w 200
19546
-
,_
215
,_ 1; 210
' -,_
~ ~ '' ' ,_ T -~
..... ~
~ ~ --205 .... --{ --
200
LEGEND
--500-YEAR FLOOD
- - -100-YEAR FLOOD
~STREAM BED
48 50 52 54 56 58 60
STREAM DISTANCE IN HUNDREDS OF FEET ABOVE THE CORPORATE LIMITS
Figure 15 -Data Extrapolation Method -Profile
V-10
Guide For Approximate Zone A Areas Developing BFBs
Detailed Methods
Three essential factors must be determined either by hand
calculations or by computer model to determine a BFE by
detailed methods. These factors are: 1) floodplain geometry
(topography); 2) flood discharge and/or volume (hydrology);
and 3) flood height (hydraulics).
Topography involves the measurement of the geometry of a cross
section(s) of the floodplain, which includes horizontal and
vertical coordinates. The vertical coordinate, or elevation,
is related to a vertical datum, such as the National Geodetic
Vertical Datum of 1929 or North American Vertical Datum of
1988. The horizontal coordinate, or station, is measured from
a reference point along the cross section to establish actual
ground points.
Hydrology for the particular location along a stream involves
the determination of the peak rate of stream flow [usually
measured in cubic feet per second (cfs)] that will occur
during a flood {for purposes of determining the BFE, the 100-
year flood) . When determining lake or pond elevations, a 100-
year flood hydrograph is required to determine the BFE.
Hydraulics involves the determination of the water-surface
elevation that will occur during a flood (for purposes of
determining the BFE, the 100-year flood), the selection of a
method to relate the flood discharge to a flood depth, and the
selection of Manning's roughness coefficients or "n" values.
These "n" values vary depending on the type of materials;
degree of irregularity; variation of shape, obstructions, and
vegetation; and degree of meandering related to the channel
and the floodplain of a stream.
The following sections discuss various methods for determining
the topography, hydrology, and hydraulics for a particular
location in order to determine a BFE.
Topography
Existing Topographic Maps
Before initiating field surveys, determine if there is
existing detailed topographic mapping that can be used to
generate cross-section data. To adequately describe a
floodplain and for use with a hydraulic method to calculate a
BFE, topographic map scales and contour intervals must be the
same as, or more detailed than, those used to prepare the
V-11
Guide For Approximate Zone A Areas Developing BFEs
community's Flood Insurance Study. The greater the level of
detail on the topographic map, the more accurate the BFE
determination. If the community does not have a Flood
Insurance Study, an existing topographic survey should, at a
minimum, be as detailed as the U.S. Geological Survey
quadrangle map for the area. Regardless of the level of
detail of the existing topographic map used, it is suggested
that the geometry of the actual stream channel be obtained by
a site visit if the cross sections are to be used for
hydraulic analyses.
Datum Requirements for Field surveys
If a greater level of detail is desired than is available from
existing topographic mapping, then a field survey should be
performed. If it is necessary to establish a BFE for
insurance purposes or to meet the requirements of 60.3 of the
NFIP Regulations, the survey must be referenced to the same
datum that is used to produce the FIRM, which is usually the
National Geodetic Vertical Datum of 1929 or the North American
Vertical Datum of 1988. Reference marks giving elevations to
this datum are given in the published Flood Insurance studies.
If the reference marks cannot be located in the field, or are
simply too far away, additional reference mark information may
be obtained from the State's U.S. Geological Survey or
Transportation office. Local surveyors are generally familiar
with nearby reference marks. In approximate Zone A areas, if
it is not economically feasible to reference survey
information to a known reference mark, an assumed datum may be
used, provided that the BFE, structure, and lot elevations are
referenced to the same assumed datum; however, data developed
using such an assumed datum may not be sufficient to revise a
FIRM. All surveys must be certified by a registered
professional engineer or land surveyor.
If the sole purpose of determining relative flood heights is
to meet the requirements set forth in Section 60.3(a) of the
NFIP regulations, any assumed datum may be used. In this
instance, a depth of flooding can be established at a
particular location without having to reference it to a datum
(i.e., National Geodetic Vertical Datum). However, in order
for an insurable structure to be eligible for a lower
insurance rate based on the BFE, the survey may need to be
referenced to the same datum that was used for the FIRM (i.e.,
National Geodetic Vertical Datum or North American Vertical
Datum).
V-12
Guide Por Approximate zone A Areas Developinq BPE•
Number of cross Sections Required
If the determination of the BFE is for only one lot, one cross
section is required across the 100-year floodplain through the
property in question. For large parcels and multi-lot
subdivisions, at least one cross section is required at each
end of the parcel or subdivision. Additional cross sections
must be added if the difference in the computed 100-year
water-surf ace elevations at the two cross sections is more
than one foot and the distance between the cross sections is
greater than 500 feet.
Proper Location of Cross Sections
The following guidelines should be used to determine the
proper location for cross sections:
Flow Path: Cross sections must be oriented perpendicular
to the anticipated flow path of the 100-year flood, as
shown in Figure 16, "Cross Section Orientation."
Channel Characteristics: Cross sections should be
located where changes in channel characteristics, such as
slope, shape, and roughness, occur.
Discharge: Cross sections should be located at points
along a stream where changes in flood discharge occur,
such as upstream of tributaries, as shown in Figure 17,
"Locate Cross Sections at Points of Flood Discharge
Changes."
Structures: A minimum of two cross sections are required
to compute a BFE at or near a structure, such as a bridge
or dam. If the floodplain configurations upstream and
downstream of the structure are similar, two cross
sections may be used. One cross section should represent
the structure profile including the profile of the road
or embankment. When obtaining the structure profile in
the field, . measurements of the structure opening, if
there is one, and any piers should also be obtained. The
other cross section should represent the natural valley
cross section downstream of the structure and should not
include any part of the structure or embankment. The
natural valley cross section should be located at a
distance equal to the width of the structure opening, W,
measured from the downstream foot of the embankment or
wing walls, as shown in Figure 18, "Cross Section
Locations at Structures."
V-13
Guide For Approximate Zone A Areas Developing BFEs
A\---;---
Figure 16 -Cross Section Orientation
Drainage
area
boundary
Figure 17 -Locate Cross Sections at Points of
Flood Discharge Changes
V-14
Guide For Approximate Zone A Areas
Water's Edge
Flow
1.. l w .. 1
Bridge
l
Fbw ~
Developing BFEs
w
Water's Edge
Figure 18 -Cross Section Locations at Structures
If the floodplain configurations upstream and downstream
of the structure are different and the structure is a
bridge, an additional cross section should be used
upstream of the structure. The cross section should be
located at a distance equal to the width of the structure
opening upstream of the structure as measured from the
foot of the embankment or wing walls.
The stations and elevations for cross section ground
points outside of the stream channel may be obtained from
a topographic map. The size of the structure opening,
piers, and channel geometry, however, should be obtained
by field survey.
Hydrology
There are a number of methodologies that may be used to
develop flood discharges for approximate Zone A areas. The
methods discussed below were selected because they are fairly
simple to use, require information that is easily obtainable,
and provide reasonable discharge estimates for streams where
more detailed hydrologic analyses have not been performed.
These methods, which have been ordered based on ease of use
and expected level of accuracy, include discharge-drainage
area relationships, regression equations, the NRCS TR-55
graphical peak discharge and tabular hydrograph methods, and
V-15
Guide For Approximate Zone A Areas Developinq BFEs
the rational formula. Other hydrograph methods will also be
noted but not described in detail due to their complexity.
Discharqe-Drainaqe Area Relationships
This method is suggested for approximate Zone A areas because
it is straightforward and the only data needed are drainage
areas and corresponding 100-year flood discharges. These data
can be obtained from the Summary of Discharges table in a
Flood Insurance Study report.
The relationship between drainage area and discharge is non-
linear in most cases; therefore, the drainage areas and
corresponding 100-year flood discharges from the Flood
Insurance study should be plotted on log-log paper as shown in
Figure 20 from 'the example which begins on the following page.
The s t reams plotted may have varying drainage areas; however,
other watershed characteristics should be similar. A straight
line should be drawn through the plotted points as shown in
Figure 21. The 100-year flood discharge for a particular
location can then be estimated based on the drainage area at
the location as shown in Figure 21 from the example.
Limitations -If the relationship of plotted points cannot be
approximated by a straight line, then this method should not
be us e d. In addition, this method is not appropriate when the
stream along which the site is located is regulated by dams,
detention ponds, canals, or other flow control structures or
diversions.
V-16
Guide For Approximate Zone A Areas Developinq BFEs
EXAMPLE: DISCHARGE-DRAINAGE AREA RELATIONSHIPS
The following is a Summary of Discharges table from a Flood
Insurance Study report.
TABLE 1 -SUMMARY OF DISCHARGES
FLOODING SOURCE DRAINAGE AREA PEAK DISCHARGES (cfs)
AND LOCATION (sg. miles} 10-YEAR 50-YEAR 100-YEAR 500-YEAR
PINE CREEK
At confluence with
Saddle River 20.39 2,220 4,165 5,310 9,010
At Calvin Street 16.3 1,907 3,617 4,612 7,300
At Caitlin Avenue 14.9 1,860 3,285 4,090 6,570
ROCK RUN
Downstream of confluence
of Ramsey Brook 12.6 1,640 2,895 3,605 5,795
Upstream of confluence
of Ramsey Brook 10.1 1,390 2,455 3,055 4,910
GOOSE CREEK
Downstream of confluence
of Valentine Brook 9.1 1,285 2,270 2,825 4,540
Upstream of confluence
of Valentine Brook 6.2 965 1,700 2,120 3,405
COON CREEK
Downstream of confluence
of Allendale Brook 14.3 1,805 3,185 3,965 6,370
Upstream of confluence
of Allendale Brook 12.9 1,670 2,950 3,670 5,900
Assume that Wendy Run is a stream within the same community as
the streams listed in the table, and that the Wendy Run
drainage basin, shown in Figure 19, has similar
characteristics to the stream basins from the table. First,
plot the drainage areas and corresponding 100-year discharges
on log-log paper as shown in Figure 20 on the following page.
Then draw a straight line through the plotted points as shown
in Figure 21.
At Property A, the drainage area for Wendy Run is 8.5 square
miles. Using the drainage area curve created from the Flood
Insurance Study Summary of Discharges table, the 100-year
discharge at Property A is estimated to be 2,750 cfs, as shown
on Figure 21. At Property B, with a drainage area of 12.0
square miles, an estimated 100-year discharge of 3, 600 is
obtained, as shown on Figure 21.
V-17
Guide For Approximate Zone A Areas
D ra inage
area
b oundary
Develop i ng BFEs
Figure 19 -Wendy Run Drainage Basin
'O c:
0 u
Q)
(/) ....
Q) a..
Qi
Q) u.
u
:0
:J
~
Q)
Cl .... ns .c: u
II)
0
~ ns
Q) a..
Frequency Discharge Drainage Area Curve
10000
I
I
I I
~ '
I y '
~ -)~
I II I ~
I
1000 . 1 10 100
Drainage Area (Square M iles)
Figure 20 -Discharge-Drainage Area Plot
V-18
Guide For Approximate Zone A Areas
'O c:
0
(J
Q)
(J) ....
Q) a..
a;
Q)
10000
u. 3600
(J :c
:J
Q. 2750
Q)
Cl .... cu ..c:
(J
fl)
0
..l<:
al
Q) a..
1000
Discharge-Drainage Area Curve
I
I -~ _.____ ·-1-·
I y
~ --------;r
~ --1--. -' I ---1
'
Vi I II I
I I I
11
I
I I I
11 I
I
I
I I ~ I
I
1 a.s 10 ~2.o
Drainage Area (Square Miles)
Developinq BFEs
I
I
-
I
1 00
Figure 21 -100-year Discharge Estimates for
Site A and Site B
Reqression Equations
Another methodology that can be used for determining
discharges for approximate Zone A areas is the application of
the appropriate regression equation found in a U.S. Geological
Survey publication (Water Resources Investigation or Open File
report). A list of these publications applicable to each
State is in Appendix 4. The U.S. Geological Survey has also
released Version 1.1 of the National Flood Frequency Computer
Program. The National Flood Frequency Program contains the
regression equations for all of the continental United States.
The use of regression equations involves the determination of
specific variables for a watershed (drainage area, mean annual
precipitation, forest cover, stream slope, etc.). Regression
equations are based on actual stream gage data and are usually
developed to determine discharges for the 2-year event up to
the 100-year event (for purposes of determining the BFE,
determine the 100-year discharge).
V-19
Guide For Approximate zone A Areas Developing BFEs
The general form of these regression equations is:
where: Q = discharge (cfs)
K = regression equation constant
A,B,
and c ::.! watershed variables
X,Y,
and z = exponents
Watershed variables may include parameters such as drainage
area (in square miles) , stream slope (in feet/mile), and
impervious area (in percent).
Limitations -Care must be taken when using these publications
because restrictions generally apply when the watershed is
heavily urbanized (i.e., high percentage of impervious land),
or where the runoff is regulated by the use of dams, detention
ponds, canals and other flow diversions. Other restrictions
based on the physical parameters of the watershed, such as
drainage area or stream slope, may also apply. Limitations of
these equations are normally stated in each report and should
be examined closely.
TR-55
The NRCS TR-55 "Urban Hydrology for Small Watersheds" contains
two methods for computing flood discharges: the Graphical
Peak Discharge method and the Tabular Hydrograph method. TR-
55 is straightforward in its approach and method of
computation. TR-55 takes into account the effects of
urban i zation, rainfall distribution, soil types and
conditions, ground cover types, and other watershed
characteristics. A method for estimating the effects of
storage on peak flood discharges is also included in TR-55.
Limitations -In general, TR-55 should not be used in areas
where flow is divided between closed storm sewer systems and
overland conveyance areas, or where drainage areas exceed
2,000 acres. More specific limitations for using TR-55 are
contained in Chapters 2 through 6 of the NRCS TR-55 manual.
Rational Formula
This method estimates peak discharge rates for small watershed
areas not covered by regression equations and for areas where
the NRCS TR-55 method is not applicable. The Rational Formula
V-20
Guide For Approximate Zone A Areas Developing BFEs
is based on the drainage area, rainfall intensity, watershed
time of concentration, and a runoff coefficient. The
generalized equation is:
where: Q
c
I
A
Q = C * I * A
= discharge (cfs)
= runoff coefficient
= rainfall intensity (inches/hour)
= drainage area (acres)
The runoff coefficient, c, var i es with soil type, land use,
and terrain slope and can be obtained from text books on
hydrology. The intensity of rainfall, I, is determined based
on the total rainfall for a selected exceedence probability
and a duration equal to the time of concentration for the
watershed. The time of concentration for the watershed can be
computed using the method described in the NRCS TR-55 manual
or methods described in hydrology text books. For approximate
Zone A areas, the exceedence probability is equal to 1 percent
(100-year storm frequency). The 1 percent exceedence
probability total rainfall (100-year rainfall) for the
computed duration can be obtained from Technical Paper No. 40,
Hydro 35, and precipitation-frequency atlases published by the
National Weather Service. Dividing the total rainfall by the
computed duration will yield the intensity of rainfall.
Limitations -This method must not be used where the runoff is
regulated by the use of dams, detention ponds, canals and
other flow diversions. Also, this method is not recommended
for drainage areas greater than 200 acres, but can be used
with caution for drainage areas up to 640 acres (one square
mile) .
Other Hydrograph Methods
There are numerous other methods that can be used to determine
flood discharges based on rainfall-runoff relationships. The
following hydrograph methods are described in detail within
their respective technical reports and, therefore, will not be
described in detail within this guide. These methodologies in
general are good for any size watershed, and most of the
methods include computations that take into consideration
areas where the runoff is regulated by the use of dams,
detention ponds, canals and other flow diversions. These
methods are recommended for determining BFEs for ponds or
lakes that are designated as approximate Zone A. Besides TR-
55, two of the more widely used hydrograph methods are the
V-21
Guide For Approximate Zone A Areas Developing BFEs
NRCS' TR-2 o and the U. s. Army Corps of Engineers' HEC-1
computer programs.
TR-20 and HEC-1 provide a very detailed calculation of
discharge through the generation, addition, and routing of
runoff hydrographs. The effect on peak flood discharges due
to dams, road crossings, and large floodplain storage areas is
more accurately assessed with these programs. These models
require experience on the part of the user if they are to
produce realistic determinations of peak discharge.
Limitations -The limitations of these methods are thoroughly
described in their manuals. Because these methods involve
many variables and assumptions, the potential for error is
great. The users of these models must be thoroughly versed in
the limitations and assumptions of the computational methods
contained in these models. As with any synthetic model
depicting rainfall-runoff relationships, extreme care needs to
be taken to ensure that the results of the model are
reasonable. It is highly recommended that the discharges
produced by these hydrograph methods be compared to discharges
produced by another hydrologic method of equal accuracy or by
calibrating the model to an actual storm event.
Hydraulics
There are various hydraulic methods that may be used to
determine BFEs along riverine flooding sources. The
appropriate method to use depends on flow conditions and the
size of the area that is being analyzed. For developments of
equal to or less than 50 lots or 5 acres, the normal depth
method, which is described in greater detail below, is usually
adequate for determining BFEs. After normal depth has been
computed, flow conditions should be analyzed. If flow is
class i fied as subcritical (i.e., normal depth is greater than
critical depth), normal depth is used as the BFE. If flow is
classified as supercritical (i.e., normal depth is less than
critical depth), then critical depth is used as the BFE for
natural channels. For engineered channels, supercritical
(normal) depth may be used for the BFE, provided that the
backwater from the normal depth of the downstream cross
section is considered properly. If more than one cross
section is required, step-backwater computations should be
used to determine BFEs along riverine flooding sources.
The procedures for computing normal depth, critical depth, and
step-backwater by hand are outlined below. As an alternative
to hand calculations, the QUICK-2 computer program may be
V-22
Guide For Approximate Zone A Areas Developing BFEs
used. QUICK-2 is a user-friendly computer program developed
by FEMA that may be used for normal depth, critical depth, or
step-backwater computations for regular or irregular shaped
cross sections. To aid the users of this guide in computing
BFEs, the QUICK-2 computer program and user's manual are
located in Appendix 6. The user's manual contains a tutorial
section which leads a new user through the calculation process
using "real life" examples. For those not using the QUICK-2
program, the following sections on Normal Depth and Critical
Depth illustrate how to compute these depths by hand (see
Appendix 8 for an example of a Normal Depth hand calculation) .
Normal Depth
Normal depth is the depth expected for a stream when the flow
is uniform, steady, one-dimensional, and is not affected by
downstream obstructions or flow changes. For uniform flow,
the channel bottom slope, water-surface slope, and energy
slope are parallel and are, therefore, equal. For normal
depth computations, the flow is considered steady because the
discharge is assumed to be constant; therefore, the depth of
flow does not change during the time interval under
consideration.
Normal depth calculations (also called the "slope/area
method") compute BFEs at a cross section. The standard
formula for determining normal depth at a cross section is
Manning's formula. The standard Manning's equation is:
Q = 1. 4 8 6 x A x ( R 667 ) x s ·5 / n
where: Q = discharge (cfs)
A = cross section area (ft2 )
R = hydraulic radius (ft) = A/WP
WP = wetted perimeter (ft)
s = energy slope (ft/ft)
n = Manning's roughness coefficient
The cross section area refers to the area below the water-
surface elevation, and the wetted perimeter refers to the
length of the ground surf ace along the cross section below the
water-surface elevation. The channel bottom slope is used in
lieu of the energy slope.
As noted earlier, Manning's "n" values vary depending on the
physical features of the stream channel and the channel
over banks. The results of normal depth calculations can
V-23
Guide For Approximate Zone A Areas Developing BFEs
differ significantly depending on the Manning's "n" values
used; therefore, care should be taken to ensure that the
Manning's "n" values selected accurately reflect conditions at
the site being analyzed. Manning's "n" values should be
selected based on field inspection, field photographs, and
topographic mapping. A list of accepted Manning's "n" values
has been included in Appendix 5. Various methods for
computing normal depth are described below.
Computer Programs for Computing Normal Depth
In addition to QUICK-2, the following Federal Government
computer programs have the capability to perform normal depth
computations:
Computer Program
HEC-2
HEC-RAS
WSPRO
WSP2
SFD
PSUPRO
Agency
U.S. Army Corps of Engineers
U.S. Army Corps of Engineers
U.S. Geological Survey
NRCS
FEMA
FEMA
Please note that HEC-RAS is still being tested and had not yet
been r eleased to the general public when this guide was
published. Furthermore, FEMA has not yet approved the model
for requests to revise NFIP maps. Please contact our
Headquarters off ice to determine the current status of HEC-
RAS.
In addition to the above-referenced programs, there are other
engineering computer programs and models, which perform normal
depth calculations, that are available through various
commercial vendors. References for the hydraulic computer
programs listed above are in Appendix 7.
Normal Depth Hand Calculations
If a computer is not available, it is possible to perform hand
computations to calculate normal depth for the 100-year flood
at a cross section by following steps 1-11 listed below.
Step 1 -Obtain a topographic map or conduct a field survey
to obtain a cross section at the site where normal
depth should be determined. If a topographic map
is used, the channel geometry should be obtained
from measurements taken in the field. The cross
section should be oriented perpendicular to the
expected 100-year floodplain.
V-24
J
1
' 1
j
Guide For Approximate Zone A Areas Developinq BFEs
Step 2 -Compute the 100-year discharge by applying one of
the methods described in the hydrology section of
this guide.
Step 3 -Plot the cross section on graph paper with
stations and the corresponding elevations.
stations and elevations are obtained from
topographic map and/or from field survey).
the
(The
the
Step 4 -Select the left and right channel bank stations.
The channel bank stations are those stat i ons where
the ground slope becomes flatter moving away from
the channel bottom as shown in Figure 22, "Channel
Bank stations." Photographs taken in the field and
the contours on the topographic maps are also
helpful when defining the channel bank stations.
Do not place the channel bank stations at the
bottom of the channel.
I "CHANNE L BANKS~ I
Figure 22 -Channel Bank Stations
Step 5 -Select appropriate Manning's roughness coefficients
for the left overbank, channel, and right overbank
from the "n" values given in Appendix 5. These
values should be determined by reviewing the field
photographs and visiting the site.
Step 6 -compute the cross section area, wetted perimeter,
hydraulic radius, and conveyance for each segment
(i.e., left overbank, channel, and right overbank)
for at least three elevations. The conveyance, K,
of a segment is given as:
where: A =
R =
K = (1.486/n) x A x RQ~?
cross section area (ft2 )
hydraulic radius (ft)
V-25
Guide For Approximate Zone A Areas
WP = wetted perimeter (ft)
R = A/WP
Developinq BPB•
Step 7 -Compute the channel bottom slope, S, from the
topographic map or from field survey.
Step 8 -Compute the discharge, Q, for each segment of the
cross section at each elevation by multiplying K by
s0.5.
Step 9 -Add the discharges from each segment at the same
elevation to obtain the total discharge.
step 10 -Plot the total discharges and the corresponding
elevations on graph paper.
Step 11 -The BFE can be determined from this graph for the
100-year flood discharge computed in Step 2.
An example of a normal depth hand calculation is included in
Appendix 8.
critical Depth
After computing normal depth, the type of flow should be
checked. If the velocity head from the normal depth
computation is equal to or more than half the hydraulic depth,
the flow is supercritical and the critical depth should be
used to establish the BFE. The velocity head, HV, for an
irregular cross section is computed using the following
equation:
where: a =
v =
QT =
AT =
g =
uv2
HV=-2g
velocity coefficient
mean velocity = Or (fps)
Ar
total discharge (cfs)
total flow area (ft2 )
acceleration due to gravity = 32.2 ft/sec2
The velocity coefficient, a, is determined using the following
equation:
((Kif Af) + (K~/ A~) + (~/A:))
f4.I A~)
V-26
Guide For Approximate zone A Areas Developinq BP'Es
where: conveyance for left overbank,
channel, right overbank, and
total conveyance, respectively
flow area for left overbank,
channel, right over bank, and
total flow area, respectively
Hydraulic depth, h, is computed by using the following
relationship:
where:
h = AT
T
T = top water-surface width at the normal depth
AT = Total Flow Area
If the velocity head is greater than or equal to one-half the
hydraulic depth, the flow is supercritical.
For prismatic channels, the following equation can be used to
determine the critical depth:
02 A3 - = -or 0 = ./gA 3I1 g T
For a series (3 or more) of water-surface elevations, compute
the corresponding total area, A, water-surface topwidth, T,
and the critical discharge, Q, using o = ./gA 3 /T. Compute the
value of right hand side of the above equation. Plot the
water-surf ace elevations and the corresponding discharge
values on graph paper. The critical water-surface elevation
and, therefore, critical depth, can be determined from this
graph for a range of discharge values.
For rectanqular channels, critical depth can be computed
directly from the above equation and is expressed in the
following relationship:
[
0 ]0.661
DC= (5 .67T)
The energy is minimum at the critical depth. For irreqular
cross sections, critical depth is determined from the
relationship between the water-surf ace elevation and the
energy. The energy is computed by adding the water-surface
elevation and the corresponding velocity head (or energy grade
elevation). For irregular cross sections, the velocity
coefficient, a, must be considered when computing velocity
head (HV) . Several water-surface elevations should be assumed
and corresponding energy grade elevations computed. These
values are then plotted on a graph of water-surf ace elevation
V-27
Guide For Approximate Zone A Areas Developinq BFEs
versus energy grade elevation. The critical
elevation and, therefore, critical depth, can
from this graph where the energy (i.e.,
elevation) is minimum.
step-Backwater Analysis
water-surface
be determined
energy grade
Step-backwater computations are based on the principle of
conservation of energy, which states that the energy at the
upstream cross section is equal to the energy at the
downstream cross section plus the losses between the two cross
sections. The losses considered in the step-backwater
analysis are the friction loss and the transition loss.
The equations and the procedure used in the step-backwater
analysis are explained in the QUICK-2 user's manual in
Appendix 6. Although hand computations can be done to perform
the step-backwater analysis, it is advisable to use the QUICK-
2 program or other Federally approved programs for ease of
computation. The QUICK-2 program currently does not model the
effects of bridges or culverts or supercritical flow.
The QUICK-2 program uses the default friction slope method,
which is the average conveyance method, from the HEC-2 program
to compute friction losses. For transition losses, a
contraction coefficient of 0.1 and an expansion coefficient of
0.3 should be used in the computations.
The reach lengths between the two cross sections for the left
overbank, channel, and right overbank are required for step-
backwater computations. The distance for the left overbank
should be measured between the center of the floodplains of
the left overbank at each cross section. The same is true for
the right overbank. The channel distance should be measured
along the streambed, and therefore will account for the
meandering of the stream channel.
In general, starting water-surface elevations are obtained
from normal depth computations (slope/ area method) at the
first cross section. If there is a structure downstream of
the study area, the b~ckwater effects of the structure must be
considered in determining the starting water-surface
elevation. If there is a known 100-year water-surface
elevation at the downstream end of the study area, that water-
surface elevation should be used as the starting water-surf ace
e l evation.
V-28
Guide For Approximate zone A Areas Developinq BFEs
Hydraulic Structures
As stated earlier, normal depth is the depth expected for a
stream when the flow is uniform, steady, one-dimensional, and
is not affected by downstream obstructions or flow changes.
However, there are si.tuations in which a physical structure
located downstream bf a particular site will cause an
obstruction or alteration of the flow, resulting in a flood
depth at the site higher than the normal depth. The
discussion below describes the appropriate methods for
determining BFEs for reaches that include hydraulic
structures.
Hydraulic structures that are common in approximate Zone A
areas include road and railroad crossings, including
embankments, dams, bridges and culverts, and canal crossings.
The flow over the road, railroad, embankment, dam or canal can
be described as weir flow. Weir flow can be calculated by hand
or by computer program in order to determine the BFE. When
flow passes through a bridge or culvert, the BFE can be
determined through the use of nomographs or computer programs.
The BFE at a structure where flow travels through a bridge or
culvert and over the crossing can be determined by nomographs,
but is more easily determined with a computer program.
Weir Flow
Determination of the water-surface elevation for weir flow
requires at least two cross sections. The first cross section
represents the natural valley section downstream of the
structure, and the second cross section represents the road
profile and the opening of the structure {refer to Figure 18,
"Cross Section Locations at Structures." If the approach
velocity head is to be considered, then a third cross section
is required that represents the natural valley section
upstream of the structure. In most situations, however, the
velocity head can be assumed to be negligible, and a third
cross section is not necessary.
The water-surface elevation downstream of the structure should
be determined by using normal depth computations at the first
cross section, provided there are no structures further
downstream that can create backwater effects {refer to the
methods for determining normal depth described previously) .
The second cross section, which represents the profile along
the top of the structure including the road or the embankment,
should be used to determine the weir length for use in the
equation for weir flow, as shown on the following page.
V-29
Guide For Approximate Zone A Areas Developinq BFEs
where: Q
@
c
L
H
=
=
=
=
=
discharge (cfs)
submergence factor
weir coefficient, varies from 2.6 to 3.0 and can
be obtained from hydraulic text books
weir length (ft)
available head (ft), measured from top of weir to
the selected energy grade elevation
Several values for H should be selected and the corresponding
discharge computed until the total weir flow is larger than
the 100-year flood discharge. Plot the discharges and the
corresponding energy grade elevations on graph paper. The
100-year flood energy grade elevation can be determined from
this graph. For an approximate analysis, the computed energy
gradien t elevation can be considered the BFE.
If the structure profile is not horizontal, as shown in Figure
23, "Weir Flow -Embankment Profile is Not Horizontal,"
several structure segments should be used and an average
energy depth, H, for that segment should be determined for use
in the above equation for selected energy grade elevations.
The sum of the weir flow from each segment will then be equal
to the total weir flow for the selected energy grade
elevation.
ROAD OR EMBANKMENT PROFILE
HAVG(2)
F i gure 23 -Weir Flow -Embankment Profile is
Not Horizontal
V-30
Guide Por Approxiaate Zone A Areas Developing BPBs
If the downstream water-surface elevation is higher than the
minimum road elevation, a submergence factor may be considered
in the weir flow computation. The submergence factor is
dependent upon the D/H ratio, where D is the downstream depth
of water above the road and H is the upstream energy grade
depth above the road, as shown in Figure 24, "Weir Flow Over
Road." The submergence factor must be considered when the D/H
ratio is more than 0.79. For a non-horizontal road profile,
the D/H ratio must be computed for each road segment. The
submergence factor, @, can be determined from the curve in
"Hydraulics of Bridge Waterways" (Reference 1, Figure 24) and
some typical values are given in the table below.
Figure 24 -Weir Flow Over Road
0.998 0.30 0.944 0.80
0.992 0.40 0.932 0.85
0.986 0.50 0.915 0.90
0.976 0.60 0.889 0.95
0.962 0.70 0.700 1. 00
Other procedures used in Federal agency backwater computer programs
can also be used to determine the submergence factor.
A third cross section may be used to determine a more accurate
water-surface elevation upstream of the structure. This may be
done by assuming water-surf ace elevations and calculating the
corresponding velocity heads (HV) until an assumed water-surface
elevation plus its velocity head at that elevation equa l the same
energy gradient elevation obtained from the weir t'low equation.
The velocity head, HV, can be calculated using the following
equation:
HV = a (Q/A)2 /2g
V-31
r
Guide For Approximate Zone A Areas Developing BFEs
where: a = velocity coefficient
Q = 100-year flood dischar~e (cfs)
A = cross section area (ft) at the assumed
water-surf ace elevation
g = Acceleration due to gravity = 32.2 ft/sec2
An example of a weir flow computation is included in Appendix 9.
Flow Through Structures
Culverts
At least two cross sections are required to determine the water-
surf ace elevation upstream of a culvert. The first cross section
should represent the natural valley cross section downstream of the
culvert, and the second cross section should represent the top of
the embankment profile and the opening of the structure (refer to
Figure 13, "Cross Section Locations at Structures"). The size,
type, length, and upstream and downstream invert elevations of the
culvert should be obtained by field survey. The wing wall angle
and the entrance opening configuration, such as sharp edge or
rounded edge, should also be determined from a field survey. The
Federal Highway Administration publication "Hydraulic Design of
Highway Culverts" (Reference 2) should be referenced before going
to the field so that all the necessary information for culvert flow
computations can be collected during one field survey. Water-
surface elevations upstream of the culvert can then be computed
using the nomographs contained in the above-mentioned publication
and the procedures outlined below.
The first cross section should be used to determine the normal
depth downstream of the culvert, which will be considered as the
tailwater (refer to section on normal depth computations).
Two computations are required to determine the headwater when using
Federal Highway Administration nomographs. One computation is for
inlet control, and the other computation is for outlet control.
The headwater elevations from the two computations are then
compared. The higher of the two should be selected as the upstream
headwater elevation. If this headwater elevation is higher than
the top of embankment profile, weir flow will occur. Perform at
least three weir flow computations for headwater elevations between
the headwater that assumes that all the flow is culvert flow (the
first computation) and the minimum top of embankment elevation.
For each selected headwater elevation, compute the culvert flow
using Federal Highway Administration nomographs. Combine the weir
flow and culvert flow for each selected headwater elevation and
plot on graph paper. The BFE for the 100-year flood discharge can
then be obtained from this graph.
V-32
Guida For Approximate Zona A Areas Developinq BFEs
If the site in question is not located immediately upstream of a
structure, a normal depth should be computed at the site. The 100-
year water-surface elevation at the site should be the higher of
the two elevations from the culvert computation and the normal
depth computation.
Federal Highway Administration nomographs predict only the energy
grade elevation upstream of the culverts. In most applications,
the velocity head is assumed to be negligible and, therefore, the
energy grade elevation approximates the actual water-surf ace
elevation. If a more accurate water-surface elevation is desired,
a hydraulic computer model, such as HEC-2, should be used to
determine the BFE. The procedure outlined in the weir flow section
to compute a water-surface elevation that corresponds to a certain
energy grade elevation may also be used to determine a BFE upstream
of a culvert.
Bridges
Although hand computations can be performed by following the
procedures for bridge routines in Federal agency computer models,
it is recommended that the water-surface elevation upstream of
bridges be determined using a computer model. The number of cross
sections required at the structure depends upon the type of bridge
routine used. Four cross sections are required if the special
bridge routine in the HEC-2 program is used, and six cross sections
are required if the normal bridge routine in the HEC-2 program is
used. Three cross sections are required if the bridge routines in
the WSPRO program and the WSP2 program are used. A step-backwater
analysis is also required to compute the water-surf ace elevations
with these bridge routines. The following programs are recommended
to compute the water-surface elevation upstream of a bridge:
Computer Program
HEC-2
*HEC-RAS
WSPRO
WSP2
Agency
U.S. Army Corps of Engineers
U.S. Army Corps of Engineers
U.S. Geological Survey
NRCS
*Not available for general use when this guide was published;
please contact our Headquarters office for current status.
V-33
Guide For Approximate zone A Areas Developing BFEs
REFERENCE
1. U.S. Department of Transportation, Federal Highway
Administration, Hydraulics of Bridge Waterways, Washington,
D.C., March 1978.
2. U.S. Department of Transportation,
Administration, Hydraulic Design of
Washington, D.C., September 1985.
V-34
Federal
Highway
Highway
Culverts,
Guide For Approximate zone A Areas Letters of Map Change
VI. OBTAINING LETTERS OF MAP CHANGE
Once detailed methods have been applied to develop BFE data, these
data may be suitable for revising an NFIP map via a Letter of Map
Correction. On October 1, 1992, FEMA implemented the use of
detailed application and certification forms for requesting
revisions to NFIP maps. Therefore, if a map revision is requested,
the appropriate forms should be submitted.
FEMA has implemented a procedure to recover costs associated with
reviewing and processing requests for modifications to published
flood information and maps. Specific information about these fees
is presented in the application and certification forms.
These forms, along with other useful documents pertaining to the
NFIP, may be obtained from our technical evaluation contractors at
the addresses listed below:
FEMA Regions I-V
Dewberry & Davis
Management Engineering and
Technical Services Division
8401 Arlington Boulevard
Fairfax, Virginia 22031
FAX: (703) 876-0073
FEMA Regions VI-X
Michael Baker, Jr., Inc.
3601 Eisenhower Avenue
Suite 600
Alexandria, Virginia 22304
FAX : ( 7 0 3 ) 9 6 0 -912 5
This information is also available through the FEMA Regional
Offices listed in Appendix 3.
To provide additional assistance to those who develop BFE data, a
worksheet that synopsizes the procedures detailed in this guide is
found in Appendix 10.
VI-1
Appendix 1
Glossary of Floodplain Analysis Terms
1-Percent Annual Chance Flood: the flood that has a one-percent chance of being
equaled or exceeded on the average in any given year; equivalent to the 100-year
flood.
100-Year Flood: the flood that is equaled or exceeded once in 100 years on the
average; equivalent to the one percent annual chance flood.
Alluvial Streaa: a stream that has formed its channel by the process of
aggradation. The sediment in the stream is similar to the material in the bed
and banks.
Base Flood: the flood having a one percent chance of being equalled or exceeded
in any given year (the 100-year flood).
Base Flood Elevation (BFE): the water-surface elevation associated with the base
flood.
Conveyance: a measure of the carrying capacity of the channel section. Flow
(Discharge (Q)) is directly proportional to conveyance (K). The pror,ortional
factor is the square root of the energy slope; expressed as Q = K * s ~.
Cross Section: a vertical profile of the ground surface taken perpendicular to
the direction of flood flow. The profile is defined by coordinates of ground
elevation and horizontal distance (station).
Discharge: a measure of flow volume per unit of time.
flow are usually cubic feet per second (cfs).
In hydrology, units of
Exceedence Frequency: the frequency that a flood of a certain discharge will be
equaled or exceeded in any given year; equal to the inverse of the recurrence
interval.
Flood: (a) a general and temporary condition of partial or complete inundation
of normally dry land areas from: (1) the overflow of inland or tidal waters; (2)
the unusual and rapid accumulation or runoff of surface waters from any source;
(3) mudslides (i.e., mudflows), which are proximately caused by flooding as
defined in (a)(2) above and are akin to a river of liquid and flowing mud on the
surfaces of normally dry land areas, as when earth is carried by a current of
water and deposited along the path of the current. (b) The collapse or
subsidence of land along the shore of a lake or other body of water as a result
of erosion or undermining caused by waves or currents of water exceeding
anticipated cyclical levels or suddenly caused by an unusually high water level
in a natural body of water, accompanied by a severe storm, or by an unanticipated
force of nature, such as flash flood or abnormal tidal surge, or by some
similarly unusual and unforeseeable event, which results in flooding as defined
in (a) (1) above.
Flood Crest: the maximum height of a flood, usually measured as an elevation or
depth.
Flood Hazard: the potential for inundation that involves the risk to life,
health, property, and natural floodplain values.
Al-1
Floodplains any land area, such as the lowland and relatively flat areas
adjoining inland and coastal waters, susceptible to being inundated by water from
any source.
Floodwayz the channel of a river or other watercourse and the adjacent land areas
that must be reserved in order to discharge the base flood without cumulatively
increasing the water-surface elevation more than a designated height. The base
flood is defined as the one-percent chance flood and the designated height is
usually one foot above the base flood elevation; however, this height may vary
(but is not more than one foot) depending on what the State has adopted.
Floodway Fringe: the area between the floodway boundary and the 100-year
floodplain boundary.
Flow: equivalent to discharge.
Flow Area: the cross section (see discharge) area of the floodplain below a given
water-surface elevation.
Hazardous Flow: conditions that exist when the product of the depth of flow and
its corresponding velocity are greater than ten (10). For example a flow depth
of 3 feet and a flow velocity of 4 feet per second ( 3 x 4 = 12) would be
considered hazardous flow.
Hydraulic Depth: an average depth computed as the Flow Area divided by the top
width of the floodplain for a given water-surface elevation.
Lacustrine Flooding: Flooding produced by a lake or pond.
Peak Discharge: the maximum instantaneous discharge of a flood at a given
location.
Recurrence Interval: the average interval of time required for a flood of a
specific discharge to occur or be exceeded; equal to the inverse of the
exceedence frequency.
Riverine Flooding: Flooding produced by a river or stream.
Shallow Flooding: a designated AO, AH, or VO zone on a community's Flood
Insurance Rate Map with a one percent or greater annual chance of flooding to an
average depth of one to three feet where a clearly defined channel does not
exist, the path of flooding is unpredictable, and velocity flow may be evident.
Such flooding is characterized by ponding or sheet flow.
Slope (Energy): the rate of energy loss of a watercourse.
Slope (Ground): the change in vertical ground elevation over a horizontal
distance, usually based on the change in the vertical elevation of the stream
bottom.
Steady Flow: state of flow where the depth of flow does not change with time.
Subcritical Flow: state of flow where the gravitational forces are more
pronounced than the inertial forces. The flow tends to have a low velocity. In
general, in this flow regime, the hydraulic depth is more than twice the velocity
head.
Supercritical Flow: state of flow where the inertial forces become dominant. The
flow tends to have a high velocity. In general, in this flow regime, the
velocity head is equal to or more than half the hydraulic depth.
Unsteady Flow: state of f l ow where the depth of flow changes with time.
Al-2
Appendix 1 -continued
Glossary of Floodplain Analysis Tera•
Unifora Flow: depth is constant over channel length, and the channel shape, slope
and boundary roughness are constant over the channel length.
Varied Flow: depth of flow changes along the channel length.
Gradually Varied Flow: depth of flow changes gradually over the channel length.
Rapidly Varied Flow: depth changes abruptly over a short channel length.
Velocity: a rate of movement (i.e., distance divided by time). For water, the
rate is expressed in feet per second. Because water in a channel does not all
move at the same velocity at every point, an average value is used to described
flow velocity. This average velocity equals the discharge divided by the flow
area (Q/A).
Velocity Bead: the kinetic energy term (a V2 / 2g), in the total energy of flow.
The velocity coefficient (a) is used to adjust for the distribution of velocity
in a cross section of differing roughness.
Al-3
Appendix 2
Flood Insurance Study Data Request Fora
FLOOD INSURANCE STUDY (FIS) DATA REQUESTS
Requests for FIS data should be made in writing to:
Regions I-V
Flood Insurance Information
Specialist
c/o Dewberry & Davis
2953 Prosperity Avenue
Fairfax, Virginia 22031
FAX: (703) 876-0073
Regions VI-X
FEMA Project Library
c/o Michael Baker, Jr., Inc.
3601 Eisenhower Avenue
Suite 600
Alexandria, Virginia 22304
FAX: (703) 960-9125
The following information should be included in your written request:
• Complete community name (including county)
• Community Identification Number
• Name(s) of flooding source(s) and specific location(s) for which
data are needed
• Specific data needed:
HEC-2 input and output files
Topographic data
etc.
• Effective date of FIRM/FBFM for which data are requested (enclose an
annotated copy of FIRM/FBFM if available identifying area of interest)
• Agreement to pay costs associated with processing the request
Fee limit after which authorization is needed
• Contact person's name, address, and phone number
The average request takes approximately 2 to 4 weeks to fill and may cost
between $100 to $200.
You will be contacted after we have determined if the data are available and
the cost to fill the request has been determined.
Do not include payment with your request letter.
Checks or money orders should be made payable to the National Flood Insurance
Program and sent to:
Federal Emergency Management Agency
Fee Collection System
P.O. Box 398
Merrifield, Virginia 22116
Data will be released upon receipt of payment.
A2-1
Appendix 3
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
Federal Emergencv Management Agency Offices
HEADQUARTERS
500 c Street, SW
Washington, D.C. 20472
(202) 646-3680
FAX: (202) 646-4596
REGION I
(Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island & Vermont)
J.W. McCormack Post Office & Courthouse Building, Room 462
Boston, MA 02109
(617) 223-9561
FAX : (617) 223-9574
REGION II
(New Jersey, New York, Puerto Rico & Virgin Islands)
26 Federal Plaza, Room 1349
New York, NY 10278
(212) 225-7200
FAX: (212) 225-7262
REGION III
(Delaware, District of Columbia, Maryland, Pennsylvania, Virginia & West
Virginia)
Liberty Square Building, Second Floor
105 South Seventh Street
Philadelphia, PA 19106
(215) 931-5512
FAX: (215) 931-5501
REGION IV
(Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina
& Tennessee)
1371 Peachtree Street, N.E., Suite 700
Atlanta, GA 30309
(404) 853-4400
FAX: (404) 853-4440
REGION V
(Illinois, Indiana, Michigan, Minnesota, Ohio & Wisconsin)
175 West Jackson Boulevard
Fourth Floor
Chicago, IL 60604
(312) 408-5552
FAX: (312) 408-5551
A3-1
Appendix 3 -continued
Federal Baergency llanag .. ent Agency Offices
and other Federal and State Agencies
Federal Baerqency Manaqeaent Agency Offices (continued)
REGIOlf VI
(Arkansas, Louisiana, New Mexico, Oklahoma & Texas)
Federal Regional Center
800 North Loop 288
Denton, TX 76201-3698
(817) 898-5165
FAX: (817) 898-5195
REGIOlf VII
(Iowa, Kansas, Missouri & Nebraska)
Federal Office Building, Room 300
911 Walnut Street
Kansas City, MO 64106
(816) 283-7002
FAX: (816) 283-7018
REGIOlf VIII
(Colorado, Montana, North Dakota, South Dakota, Utah & Wyoming)
Denver Federal Center, Bldg. 710
P.O. Box 25267
Denver, co 80225-0267
(303) 235-4830
FAX: (303) 235-4849
REGIOlf IX
(Arizona, California, Hawaii & Nevada)
Presidio of San Francisco
Building 105
San Francisco, CA 94129
(415) 923-7100
FAX: (415) 923-7147
REGIOlf X
(Alaska, Idaho, Oregon & Washington)
Federal Regional Center
130 -228th Street, SW
Bothell, WA 98021-9796
(206) 487-4678
FAX: ( 206) 487 -4613
A3-2
I
• ~
I
Appendix 3 -continued
Federal Eaergency Manageaent Agency Off ices
and Other Federal and State Agencies
Other Federal and State Agencies
ALABAMA
Alabama Department of Economics
and Community Affairs
State Planning Division
401 Adams Avenue
Montgomery, AL 36103
(205) 242-5442
U.S. Geological Survey
District Chief
Water Resources Division
520 19th Avenue
Tuscaloosa, AL 35401
(205) 752-8104
U.S. Department of Agriculture
Natural Resources Conservation
Service
665 Opelika Rd.
P.O. Box 311
Auburn, AL 36830
(205) 887-4506
NFIP State Coordinator
Mr. Gene Anderson
Director, Alabama Department
of Economic and Community Affairs
P.O. Box 5690
401 Adams Avenue
Montgomery, AL 36103-5690
(205) 242-5499
ALASKA
Alaska Department of
Community and Regional Affairs
Municipal and Regional
Assistance Division
333 West 4th Avenue, Suite 220
Anchorage, AK 99501
(907) 269-4500
U.S. Geological Survey
District Chief
Water Resources Division
4230 University Drive, Suite 201
Anchorage, AK 99508-4138
(907) 786-7100
A3-3
U.S. Department of Agriculture
Natural Resources Conservation
Service
949 East 36th Avenue
Suite 400
Anchorage, AK 99504
(907) 271-2424
NFIP State Coordinator
Mr. Bob Walsh
Municipal and Regional
Assistance Division
333 West 4th Avenue, Suite 220
Anchorage, AK 99501
(907) 269-4500
ARIZOHA
Arizona Department of Water Resources
15 South 15th Avenue
Phoenix, AZ 85004
(602) 242-1553
U.S. Geological Survey
District Chief
Water Resources Division
375 South Euclid
Tucson, AZ 85719
(.602) 670-6671
U.S. Department of Agriculture
Natural Resources Conservation
Service
3008 Federal Building
230 N. lat Avenue
Phoenix, AZ 85025
( 602) 261-6711
NFIP State Coordinator
Ms. Elizabeth A. Rieke
Director, Arizona Department
of Water Resources
15 South 15th Avenue
Phoenix, AZ 85007
(602) 542-1540
ARKANSAS
Arkansas Soil and Water
Conservation Commission
1 Capitol Mall, Suite 2D
Little Rock, AR 72201
(501) 371-1611
Appendix 3 -continued
Federal Eaergency Jlanageaent Agency Off ice•
and other Federal and State Agencie•
other Federal and State Agencies
U.S. Geological Survey
Water Resources Division
401 Hardin Road
Little Rock, AR 72211
(501) 228-3600
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Office Bldg.
700 West Capitol
P.O. Box 2323
Little Rock, AR 72203
(501) 324-6335
NFIP State Coordinator
Mr. Randy Young
Director
Arkansas Soil & Water
Conservation Commission
101 East Capitol
Little Rock, AR 72201
(501) 682-1611
CALIFORNIA
California Department of
Water Resou r ces
P.O. Box 942836
Sacramento, CA 94236-0001
(916) 653-5791
U.S. Geological Survey
District Chie f
Water Resources Division
Federal Building, Room W-2233
2800 Cottage Way
Sacramento, CA 95825
(916) 978-4633
U.S. Department of Agriculture
Natural Resour ces Conservation
Service
2121 C 2nd Str eet
Davis, CA 95616
(916) 757-8200
NFIP State Coordinator
Mr. David Kennedy, Director
California Department of
Water Resour ces
P.O. Box 942836
Sacramento, CA 94236-0001
(916) 653-7007
A3-4
COLORADO
Urban Drainage and Flood Control
District
2480 West 26th Avenue
Suite 156B
Denver, CO 80211
Colorado Water Conservation Board
State Centennial Building, Room 721
1313 Sherman Street
Denver, CO 80203
(303) 866-3441
U.S. Geological Survey
District Chief
Water Resources Division
Denver Federal Center, Building 53
Box 25046 (Mail Stop 415)
Lakewood, CO 80225-0046
(303) 236-4882
U.S. Department of Agriculture
Natural Resources Conservation
Service
655 Parfait Street
Room E200C
Lakewood, co 80215
(303) 236-2886
NFIP State coordinator
Mr. Caries c. Lile, P.E.
Director, Colorado Water
Conservation Board
State Centennial Building
1313 Sherman Street
Denver, CO 80203
(303) 866-3441
CONNECTICUT
State Department of
Environmental Protection
79 Elm Street, 3rd Floor
Hartford, CT 06106
(203) 424-3706
U.S. Geological Survey
Hydrologist-in-Charge
Connecticut Off ice
Water Resources Division
Abraham A. Ribicoff Federal
Building, Room 525
450 Main Stree"t
Hartford, CT 06103
(203) 240-3060
Appendix 3 -continued
Federal Emergency Management Agency Off ices
and Other Federal and State Agencies
Other Federal and State Agencies
U.S. Department of Agriculture
Natural Resources Conservation
Service
16 Professional Park Road
Storrs, CT 06268
(203) 429-9361
NFIP State Coordinator
Mr. Timothy Keeney, Commissioner
State Department of Environmental
Protection
165 Capitol Avenue
State Office Building
Hartford, CT 06106
(203) 566-2110
DELAWARE
Department of Natural Resources and
Environmental Control
Division of Soil and Water
Conservation
P.O. Box 1401
89 Kings Highway
Dover, DE 19903
(302) 739-4403
U.S. Geological Survey
Hydrologist-in-Charge
Delaware Off ice
Water Resources Division
Federal Building, Room 1201
300 South New Street
Dover, DE 19904
(302) 734-2506
U.S. Department of Agriculture
Natural Resources Conservation
Service
3500 South DuPont Highway
Dover, DE 19901
(302) 697-6176
NFIP State Coordinator
Mr. John A. Hughes, Director
Delaware Department of Natural &
Environmental Control
Richardson and Robbins Building
P.O. Box 1401
Dover, DE 19903
(301) 736-4411
A3-5
DISTRICT OF COLUMBIA
Department of Consumer
Regulatory Affairs
614 H Street Northwest
Washington, DC 20001
(202) 727-7170
U.S. Geological Survey
District Chief
Water Resources Division
208 Carroll Building
8600 La Salle Road
Towson, MD 21286
( 410) 828-1535
NFIP State Coordinator
Mr. Donald G. Murray, Director
Department of Consumer Regulatory
Affairs
Off ice of the Director
614 H Street, NW., Suite 1120
Washington, D.C. 20001
(202) 727-7170
FLORIDA
Department of Community Affairs
East Howard Building
2740 Centerview Drive
Tallahassee, FL 32399-2100
(904) 488-8466
U.S. Geological Survey
District Chief
Water Resources Division
227 North Bronough Street,
Suite 3015
Tallahassee, FL 32301
(904) 942-9500
U.S. Department of Agriculture
Natural Resources Conservation
Service
P.O. Box 141510
Gainesville, FL 32614
(904) 338-9500
NFIP State Coordinator
Ms. Linda Lomis Shelley, Secretary
Florida Department of Community
Affairs
2740 Centerview Drive
Tallahassee, FL 32399-2100
(904) 488-8466
Appendix 3 -continued
Federal Emergency Manageaent Agency Offices
and Other Federal and State Agencies
Other Federal and State Agencies
GEORGIA
Department o f Natural Resources
Environmenta l Protection Division
Floyd Towers East, Suite 1252
205 Butler Street Southeast
Atlanta, GA 30334
(404) 656-47 1 3
U.S. Geological Survey
District Chief
Water Resources Division
3039 Amwiler Road, Suite 130
Atlanta, GA 30360
(404) 447-9803
U .S. Department of Agriculture
Natural Resources Conservation
Service
Federal Buildi ng
355 East Hancock Avenue
P.O. Box 832
Athens, GA 30613
(404) 546-2272
NFIP State Coordinator
Mr. Joe D. Tanner, Commissioner
Georgia Department of Natural
Resources
205 Butler Street, S.E.
Floyd Towers East, Suite 1252
Atlanta, GA 30334
(404) 656-3500
HAWAII
Hawaii Board of Land and
Natural Resources
1151 Punchbowl Road, Room 220
Honolulu, HI 96813
(808) 587-044 6
U .S. Geological Survey
District Chief
Water Resources Division
677 Ala Moana Boulevard, Suite 415
Honolulu, HI 96813
(808) 522-8290
U.S . Department of Agriculture
Natural Resou rces Conservation
Service
300 Ala Moana Boulevard
P.O. Box 50004
Honolulu, HI 96850
(808) 546-3165
A3-6
NFIP State Coordinator
Mr. William w. Paty, Chairperson
Commission on Water Resource
Management and Board of Land and
Natural Resources
State of Hawaii
P.O. Box 621
Honolulu, HI 96809
(808) 587-0401
IDAHO
Department of Water Resources
State House
1301 North Orchard Street
Boise, ID 83706
(208) 327-7900
U.S. Geological Survey
District Chief
Water Resources Division
230 Collins Road
Boise, ID 83702
(208) 387-1300
U.S. Department of Agriculture
Natural Resources Conservation
Service
3244 Elder Street
Room 124
Boise, ID 83705
(208) 334-1601
NFIP State Coordinator
,•
Mr . R. Keith Higginson, Director
Idaho Department of Water Resources
1301 N. Orchard
Boise, ID 83706
(208) 327-7900
ILLIHOIS
Illinois Department of Transportation
Local Flood Plains Programs
310 South Michigan, Room 1606
Chicago, IL 60604
(312) 793-3123
U.S. Geological Survey
District Chief
Water Resources Division
Champaign County Bank Plaza
102 East Main Street
Fourth Floor
Urbana, IL 61801
(217) 398-5353
Appendix 3 -continued
Federal Eaergency Manageaent Agency Off ice•
and Other Federal and State Agencie•
Other Federal and State Agencies
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Building
2110 West Park Court
Suite C
Champaign, IL 61821
(217) 398-5212
NFIP State Coordinator
Mr. Michael Lene, Secretary
Illinois Department of Transportation
2300 s. Dirksen Parkway
Springfield, IL 62764
(217) 728-5597
IHDIAHA
Department of Natural Resources
608 State Off ice Building W-256
402 West Washington Street
Indianapolis, IN 46204-2748
(317) 232-4020
U.S. Geological Survey
District Chief
Water Resources Division
5957 Lakeside Boulevard
Indianapolis, IN 46278
(317) 290-3333
U.S. Department of Agriculture
Natural Resources Conservation
Service
6013 Lakeside Boulevard
Indianapolis, IN 46275
(317) 290-3030
NFIP State Coordinator
Mr. James B. Ridenour, Director
Indiana Department of Natural
Resources
608 State Off ice Building
Indianapolis, IN 46204
(317) 232-4020
IOWA
Iowa Department of Natural Resources
Wallace State Off ice Building
Des Moines, IA 50319-0034
(515) 281-5385
A3-7
U.S. Geological Survey
District Chief
Water Resources Division
P.O. Box 1230
Iowa City, IA 52244-1230
(Street Address:
Federal Building, Room 269
400 South Clinton Street)
(319) 337-4191
U.S. Department of Agriculture
Natural Resources Conservation
Service
Wallace Building
Des Moines, IA 50319
(515) 284-5851
NFIP State Coordinator
Mr. Larry Wilson, Director
Iowa Department of Natural Resources
Wallace State Office Building
Des Moines, IA 50319
(515) 281-5385
KAH SAS
Division of Water Resources
Kansas State Board of Agriculture
901 South Kansas Avenue, 2nd Floor
Topeka, KS 66612-1283
(913) 296-3717
U.S. Geological Survey
District Chief
Water Resources Division
4821 Quail Crest Place
Lawrence, KS 66049
(913) 842-9901
U.S. Department of Agriculture
Natural Resources Conservation
Service
P.O. Box 600
760 South Broadway
Salina, KS 67401
(913) 823-4500
NFIP State Coordinator
Mr. David L. Pope, P.E.
Chief Engineer & Director
Kansas State Board of Agriculture
Division of Water Resources
901 s. Kansas, 2nd Floor
Topeka, KS 66612-1283
(913) 296-3717
Appendix 3 -continued
Federal Eaergency Manageaent Agency Offices
and Other Federal and State Agencies
Other Federal and State Agencies
KENTUCKY
Kentucky Department
of Natural Resources
Division of Water
Fort Boone Plaza
14 Reilly Road
Frankfort, KY 40601
(502) 564-3410
U.S. Geological Survey
District Chief
Water Resources Division
2301 Bradley Avenue
Louisville, KY 40217
(502) 582-5241
u.s. Department of Agriculture
Natural Resources Conservation
Service
771 Corporate Drive, Suite 1 10
Lexington, KY 40503
(606) 224-7350
FTS 355-2749
NFIP State Coordinator
Mr. Jack Wilson, Director
Kentucky Division of Water
18 Reilly Road
Fort Boone Plaza
Frankfort, KY 40601
(502) 564-3410
LOUISIANA
Louisiana Department of
Urban and Community Affairs
P.O. Box 94455, Capitol Station
Baton Rouge, LA 70804
(504) 342-9794
U.S. Geological Survey
District Chief
Water Resources Division
P.O. Box 66492
Baton Rouge, LA 70896
(Street Address:
6554 Florida Boulevard
Baton Rouge, LA 70806)
(504) 389-0281
U.S. Department of Agriculture
Natural Resources Conservat i on
Service
3636 Government Street
Alexandria, LA 71301
(318) 487-8094
A3-8
NFIP State Coordinator
General Jude W. P. Patlin, Secretary
Louisiana Department of
Transportation & Development
P.O. Box 94245
Baton Rouge, LA 70804-9245
(504) 379-1200
MAINE
Maine State Planning Office
State House Station 38
184 State Street
Augusta, ME 04333
(207) 287-3261
U.S. Geological Survey
Hydrologist-in-Charge
Maine Office
Water Resources Division
26 Ganneston Drive
Augusta, ME 04330
(207) 622-8208
U.S. Department of Agriculture
Natural Resources Conservation
Service
USDA Building
University of Maine
5 Godfrey Drive
Orono, ME 04473
(207) 866-7241
NFIP State Coordinator
Mr. Michael W. Aube, Commissioner
Department of Economic and
Community Development
State House Station 59
State Street
Augusta, ME 04333
(207) 287-2656
MARYLAND
Maryland State Resources
Administration
Tawes State Office Building, D-2
501 Taylor Avenue
Annapolis, MD 21401
(410) 974-3041
U.S. Geological survey
District Chief
Water Resources Division
208 Carroll Building
8600 La Salle Road
Towson, MD 21286
(410) 828-1535
Appendix 3 -continued
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
Other Federal and State Agencies
U.S. Department of Agriculture
Natural Resources Conservation
Service
339 Busch's Frontage Road
Suite 301
Annapolis, MD 21401-5534
(410) 757-0861
NFIP State Coordinator
Ms. Catherine Pieper Stevenson
Director, Maryland Water Resources
Administration
Tawes State Office Building D-2
Annapolis, MD 21401
(301) 974-3896
MASSACHUSETTS
Massachusetts Water
Resources Commission
State Office Building
100 Cambridge Street
Boston, MA 02202
( 617) 727-3267
U.S. Geological Survey
District Chief
Water Resources Division
28 Lord Road
Marlborough, MA 01752
(508) 485-6360
U.S. Department of Agriculture
Natural Resources Conservation
Service
451 West Street
Amherst, MA 01002
(413) 253-4350
NFIP State Coordinator
Mr. Peter c. Webber, Commissioner
Massachusetts Department of
Environmental Management
State Office Building
100 Cambridge Street
Boston, MA 02202
(617) 727-3180 x600
MICHIGAN
Engineering Water
Management Commission
Michigan Department of
Natural Resources
P.O. Box 30028
Lansing, MI 48909
(517) 373-3930
A3-9
U.S. Geological Survey
District Chief
Water Resources Division
6520 Mercantile Way, Suite 5
Lansing, MI 48910
(517) 887-8903
U.S. Department of Agriculture
Natural Resources Conservation
Service
Room 101
1405 S. Harrison Road
East Lansing, MI 48823
(517) 337-6701
NFIP State Coordinator
Mr. Roland Harms, Director
Michigan Department of Natural
Resources
Land and Water Management Division
P.O. Box 30028
Lansing, MI 48909
(517) 373-3930
MINNESOTA
Flood Plains/Shoreline
Management Section
Division of Waters
Department of Natural Resources
500 Lafayette Road, Box 30
St. Paul, MN 55515-4032
(612) 297-2405
U.S. Geological Survey
District Chief
Water Resources Division
2280 Woodale Road
Moundsville, MN 55112
(612) 783-3100
U.S. Department of Agriculture
Natural Resources Conservation
Service
600 Farm Credit Building
375 Jackson Street
St. Paul, MN 55101
(612) 290-3675
NFIP State Coordinator
Mr. Ronald Nargang, Director
Minnesota Department of Natural
Resources
Division of Water
500 LaFayette Road, Box 32
St. Paul, MN 55515-0432
(612) 296-4800
Appendix 3 -continued
Federal Emergency Management Agency Offices
and other Federal and State Agencies
Other Federal and State Agencies
MISSISSIPPI
Mississippi Research and
Development Center
3825 Ridgewood Road
Jackson, MI 39211
(601) 982-6376
U.S. Geological Survey
District Chief
Water Resources Division
Federal Office Building, Suite 710
100 West Cap i tol Street
Jackson, MS 39269
(601) 965-4600
U .S. Department of Agriculture
Natural Resources Conservation
Service
100 w. Capitol
Suite 1321
Federal Building
Jackson, MS 39269
(601) 969-5205
NFIP State Coordinator
Mr . J. E. Maher, Director
Mississippi Emergency Management
Agency
1410 Riverside Drive
P.O. Box 450 1
Jackson, MS 39216
(601) 352-9100
MISSOURI
Department of Natural Resources
P.O. Box 176
205 Jefferson Street
Jefferson City, MO 65102
(314) 751-4422
U.S. Geological Survey
District Chief
Water Resources Division
1400 Independence Road,
(Mail Stop) 200
Rolla, MO 65401
(314) 341-0824
U.S . Department of Agriculture
Natural Resources Conservation
Service
601 Business Loop
70 West Parkdale Center, Suite 250
Columbia, MO 65202
(314) 876-0903
A3-10
NFIP State Coordinator
Director
Missouri Department of Natural
Resources
101 N. Jefferson Street
P.O. Box 176
Jefferson City, MO 65102
(314) 751-4422
MONTANA
Montana Department of Natural
Resources and Conservation
1520 East Sixth Avenue
Helena, MT 59620
(406) 444-6646
U.S. Geological Survey
Federal Building, Room 428
Drawer 10076
301 South Park Avenue
Helena, MT 59626-0076
(406) 449-5302
U.S. Department of Agriculture
Natural Resources Conservation
Service
10 E. Babcock
Room 443
Bozeman, MT 59715
( 406) 587-6811
NFIP State Coordinator
Mr. Mark Simonich, Director
Montana Department of Natural
Resources and Conservation
1520 East 6th Ave.
Helena, MT 59620
(406) 444-6699
NEBRASKA
Nebraska Natural Resources
Commission
P.O. Box 94876
Lincoln, NE 68509-4876
(402) 471-2081
U.S. Geological Survey
District Chief
Water Resources Division
Federal Building, Room 406
100 Centennial Mall North
Lincoln, NE 68508
(402) 437-5082
Appendix 3 -continued
Federal Eaergency Manageaent Agency Offices
and other Federal and State Agencies
Other Federal and State Agencies
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Building, Rm. 345
U.S. Courthouse
100 Centennial Mall, North
P.O. Box 82502
Lincoln, NE 68508-3866
(402) 437-5300
NFIP State Coordinator
Mr. Dayle Williamson, Director
Nebraska Natural Resources
Commission
P.O. Box 94876
Lincoln, NE 68509
(402) 471-2081
NEVADA
Division of Emergency Management
State of Nevada
Capitol Complex
Carson City, NV 89710
(702) 885-4240
U.S. Geological Survey
Hydrologist-in-Charge
Nevada Office
Water Resources Division
Federal Building, Room 224
705 North Plaza Street
Carson City, NV 89701
(702) 882-1388
U.S. Department of Agriculture
Natural Resources Conservation
Service
5301 Longway Lane
Building F, Suite 201
Reno, NV 89511
(702) 784-5863
NFIP State Coordinator
Mr. David McNinch
Nevada Division of Emergency
Management
2525 s. Carson
Capitol Complex
Carson City, NV 89710
(702) 885-4240
A3-11
HEW HAMPSHIRE
Off ice of Emergency Management
State Office Park South
107 Pleasant Street
Concord, NH 03301
( 603) 271-2231
U.S. Geological Survey
Hydrologist-in-Charge
New Hampshire Off ice
Water Resources Division
525 Clinton Street, RFD 2
Bow, NH 03304
(603) 225-4681
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Building
2 Madbury Road
Durham, NH 03824
(603) 868-7581
NFIP State Coordinator
Col. George L. Iverson, Director
Governor's Office of
Emergency Management
State Off ice Park South
107 Pleasant Street
Concord, NH 03301
(603) 271-2231
NEW JERSEY
New Jersey Department of
Environmental Protection and Energy
Flood Plain Management Section
CN 419
Trenton, NJ 08625-0419
(609) 292-2296
New Jersey Department of
Environmental Protection and Energy
Division of Natural and Historic
Resources Engineering and
Construction
Element
Floodplain Management Section
Station Plaza 5
501 East State Street, let Floor
Trenton, New Jersey 08625-0419
(609) 292-2296
Appendix 3 -continued
Federal Emergency Nanageaent Agency Offices
and Other Federal and State Agencies
Other Federal and State Agencies
U.S. Geological Survey
District Chief
Water Resources Division
Mountain View Office Park,
Suite 206
810 Bear Tavern Road
West Trenton, NJ 08628
(609) 771-006S
U.S. Department of Agriculture
Natural Resources Conservation
Service
1370 Hamilton Street
Somerset, NJ 08873
(908) 72S-3848
NFIP State Coordinator
Mr. Scott A. Weiner , Commissioner
New Jersey Department of
Environmental Protection and Energy
CN 402
Trenton, NJ 0862S
(609) 292-288S
HEW MEXICO
New Mexico State Engineer's Office
Bataan Memorial Building
P.O. Box 2Sl02
Santa Fe, NM 87S04-Sl02
(SOS) 827-6091
U.S. Geological Survey
District Chief
Water Resources Division
4S01 Indian School Road, NE
Suite 200
Albuquerque, NM 87110
(SOS) 262-S300
U.S. Department of Agriculture
Natural Resources Conservation
Service
P.O. Box 2007
Sl7 Gold Avenue, SW., Rm. 3 01
Albuquerque, NM 87102
(SOS) 766-3277
NFIP State Coordinator
Mr. Keith Lough
Office of Emergency Planning
and Coordination
Department of Public Safety
P.O. Box 1628
Santa Fe, NM 87S03
(SOS) 827-6091
A3-12
HEW YORK
Flood Protection Bureau
New York Department of
Environmental Conservation
SO Wolf Road
Albany, NY 12233-3S07
(Sl8) 4S7-31S,7
U.S. Geological Survey
District Chief
Water Resources Division
445 Broadway, Room 343
Albany, NY 12201
(518) 472-3107
U.S. Department of Agriculture
Natural Resources Conservation
Service
441 South Salina Street
5th floor, Suite 354
Syracuse, NY 13202
(315) 477-6508
FTS 950-5521
NFIP State Coordinator
Mr. James F. Kelly, Director
Flood Protection Bureau
New York State Department of
Environmental Conservation
50 Wolf Road, Room 330
Albany, NY 12233-3507
(518) 4S7-3157
HORTH CAROLIHA
North Carolina Department of
Crime Control and Public Safety
Division of Emergency Management
116 West Jones Street
Raleigh, NC 27603
(919) 733-3867
U.S. Geological Survey
District Chief
Water Resources Division
P.O. Box 30728
3916 Sunset Ridge Road
Raleigh, NC 27622
(919) 8S6-4Sl0
U. s .. Department of Agriculture
Natural Resources Conservation
Service
4405 Bland Avenue
Suite 205
Raleigh, NC 27609
(919) 790-2888
Appendix 3 -continued
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
Other Federal and State Agencies
NFIP State Coordinator
Mr. Joseph F. Myers, Director
North Carolina Division of
Emergency Management
116 West Jones Street
Raleigh, NC 27603
(919) 733-3867
NORTH DAKOTA
State Water Commission
900 East Boulevard
Bismarck, ND 58505
(701) 224-2750
U.S. Geological Survey
District Chief
Water Resources Division
821 East Interstate Avenue
Bismarck, ND 58501
(701) 250-4601
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Building, Rm. 270
Rosser Ave. & Third St.
P.O. Box 1458
Bismarck, ND 58502
(701) 250-4435
NFIP State Coordinator
Mr. David A. Sprycnzynatyk
State Engineer
North Dakota State Water Commission
900 E. Boulevard
Bismark, ND 58505
(701) 224-4940
OHIO
Ohio Department of Natural Resources
Flood Plain Planning Unit
Division of Water
1939 Fountain Square
Columbus, OH 43224
(614) 265-6750
U.S. Geological Survey
District Chief
Water Resources Division
975 West Third Avenue
Columbus, OH 43212
(614) 469-5553
A3-13
U.S. Department of Agriculture
Natural Resources Conservation
Service
Room 522
Federal Building
200 North High Street
Columbus, OH 43215
(614) 469-6962
NFIP State Coordinator
Mrs. Frances s. Buchholzer, Director
Ohio Department of Natural
Resources
Fountain Square
Columbus, OH 43224
(614) 264-6875
OKLAHOMA
Oklahoma Water Resources Board
600 North Harvey Avenue
P.O. Box 150
Oklahoma City, OK 73101-0150
(405) 231-2500
U.S. Geological Survey
District Chief
Water Resources Division
202 NW Sixty Sixth, Building 7
Oklahoma City, OK 73116
(405) 843-7570
U.S. Department of Agriculture
Natural Resources Conservation
Service
100 USDA
Suite 203
Stillwater, OK 74074
(405) 742-1200
NFIP State Coordinator
Mrs. Patricia P. Eaton
Executive Director
Oklahoma Water Resources Board
600 N. Harvey
Oklahoma City, OK 73101
(405) 231-2500
OREGON
Department of Land Conservation
and Development
1175 Court Street Northeast
Salem, OR 97310
(503) 373-0050
Appendix 3 -continued
Federal Emergency Management Agency Off ices
and Other Federal and State Agencies
Other Federal and State Agencies
U.S. Geological Survey
Hydrologist-in-Charge
Oregon Office
Water Resources Division
847 Northeast 19th Avenue,
Suite 300
Portland, OR 97323
(503) 251-3200
U.S. Department of Agriculture
Natural Resources Conservation
Service
2115 SE Morrison
Portland, OR 97214
(503) 231-2270
NFIP State Coordinator
Mr. Richard Benner
Oregon Department of Land
Conservation and Development
1175 Court Street, N.E.
Salem, OR 97310
(503) 378-4928
PENNSYLVANIA
Department of Community Affa i rs
317 Forum Building
Harrisburg, PA 17120
(717) 787-7160
U.S. Geological Survey
District Chief
Water Resources Division
840 Market Street
Harrisburg, PA 17043-1586
(717) 730-6900
Ms. Karen A. Miller, Secretary
Pennsylvania Department of
Community Affairs
P.O. Box 155
317 Forum Building
Harrisburg, PA 17120
(717) 787-7160
U.S. Department of Agriculture
Natural Resources Conservation
Service
One Credit Union Place
Suite 340
Harrisburg, PA 17110-2993
A3-14
NFIP State Coordinator
Federal Building
U.S. Courthouse
805 985
Federal Square Station
Harrisburg, PA 17108
( 717) 782-2202
FTS 590-2202
PUERTO RICO
Puerto Rico Planning Board
1492 Ponce De Leon Avenue, Suite 417
Santurce, Puerto Rico 00907
(809) 729-6920
U.S. Geological Survey
District Chief
Water Resources Division
GPO Box 4424
San Juan, PR 00936
(Street Address:
GSA Center, Building 652
Highway 28, Pueblo Viejo)
(809) 783-4660
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Building, Rm. 639
Chardon Avenue
GPO Box 4868
San Juan, PR 00936
(809) 753-4206
NFIP State Coordinator
Ms. Norma N. Burgos, President
Puerto Rico Planning Board
P.O. Box 41119
San Juan, PR 00940-9985
(809) 727-4444
RHODE ISLAND
Statewide Planning Program
Rhode Island Office of State Planning
1 Capitol Hill
Providence, RI 02908
(401) 277-2656
U.S. Geological Survey
Hydrologist-in-Charge
Rhode Island Off ice
Water Resources Division
275 Promanade Street, Suite 150
Providence, RI 02908
(401) 331-9050
Appendix 3 -continued
Federal Emergency Management Agency Off ices
and Other Federal and State Agencies
Other Federal and State Agencies
U.S . Department of Agriculture
Natural Resources Conservation
Service
40 Quaker Lane, Suite 46
West Warwick, RI 02886
(401) 828-1300
NFIP State Coordinator
Mr . Daniel w. Varin
Associate Director
Department of Transportation
Office of Systems Planning
1 Capitol Hill
Providence, RI 02908-5872
(401) 277-6578
SOUTH CAROLINA
South Carolina Water and Natural
Resources Commission
1201 Main Street, Suite 1100
Columbia, SC 29201
(803) 737-0800
U.S . Geological Survey
District Chief
Water Resources Division
Stevenson Center, Suite 129
720 Gracern Road
Columbia, SC 29210-7651
(803) 750-6100
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Bldg., Rm. 950
1835 Assembly St.
Columbia, SC 29201
(803) 765-5681
NFIP State Coordinator
Mr. Danny Johnson, Director
Surface Water Division
South Carolina Water Resources
Commission
1201 Ma i n Street, Suite 1100
Columbia, SC 29201
(803) 737-0800
SOUTH DAKOTA
Disaster Assistance Programs
Emergency and Management Services
500 East Capitol
Pierre, SD 57501
(605) 773-3231
A3-15
U.S. Geological Survey
District Chief
Water Resources Division
Federal Building, Room 317
200 Fourth Street Southwest
Huron, SD 57350-2469
(605) 353-7176
U.S. Department of Agricu lture
Natural Resources Conservation
Service
Federal Building, Rm. 203
200 4th Street, SW
Huron, SD 57350
(605) 353-1092
NFIP State Coord i nator
Mr. Gary N. Whitney, Director
South Dakota Department of
Military and Veteran Affa irs
Division of Emergency and
Disaster Services
500 E. Capitol
Pierre, SD 57501
(605) 773-3231
TENNESSEE
Tennessee Department o f Econ o mic
and Community Development
Division of Community Development
320 Sixth Avenue North, Sixth Floor
Nashville, TN 37243-0405
(615) 741-1888
U.S. Geological Survey
District Chief
Water Resources Di vision
810 Broadway, Suite 500
Nashville, TN 37203
(615) 736-5424
U.S. Department of Agriculture
Natural Resources Conservat i o n
Service
U.S. Courthouse, Rm. 675
801 Broadway Street
Nashville, TN 37203
(615) 736-5471
FTS 852-5471
Appendix 3 -continued
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
other Federal and State Agencies
NFIP State Coordinator
Mr. Michael McGuire
Assistant Commissioner
Tennessee Department of Economic and
Community Development
320 Sixth Avenue
North Nashville, TN 37219-5408
(615) 741-2211
TEXAS
Texas Natural Resource
Conservation Commission
P.O. Box 13087
Capitol Station
Austin, TX 78711-3087
(512) 239-1000
U.S. Geological Survey
District Chief
Water Resources Division
8011 Cameron Road
Austin, TX 78754
(512) 873-3000
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Bldg.
101 s. Main Street
Temple, TX 76501
(817) 774-1214
NFIP State Coordinator
Mr. Jesus Galza
Executive Director
Texas Water Commission
P.O. Box 13087
Capitol Station
Austin, TX 78711-3087
(512) 463-7791
UTAH
Office of Comprehensive
Emergency Management
State Office Building, Room 1110
Salt Lake City, UT 84114
(801) 538-3400
U.S. Geological Survey
District Chief
Water Resources Division
2363 Foothill Drive
Salt Lake City , UT 84109
(801) 467-7970
A3-16
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Building
125 s. State Street
P.O. Box 11350
Salt Lake City, UT 84147
(801) 524-5068
NFIP State Coordinator
Ms. Lorayne Frank, Director
Department of Public Safety
Division of Comprehensive Emergency
Management
State Office Building, Room 1110
450 North Main
Salt Lake City, UT 84114
(801) 538-3400
VERMONT
Agency of Natural Resources
Department of Environmental
Conservation
Water Quality Division
103 South Main Street -lON
Waterbury, VT 05671-0408
(802) 241-3777
U.S. Geological Survey
District Chief
Water Resources Division
P.O. Box 628
Montpelier, VT 05602
(802) 828-4479
U.S. Department of Agriculture
Natural Resources Conservation
Service
69 Union Street
Winooski, VT 05404
(802) 951-6795
NFIP State Coordinator
Mr. Chuck Clarde, Secretary
Agency of Natural Resources
Center Building
103 South Main Street
Waterbury, VT 05671-0301
(802) 244-7347
Appendix 3 -continued
Federal Baergency llanageaent Agency Offices
and other Federal and State Agencies
Qt.her Federal and State Agencies
VIRGIN ISLAllDS
Virgin Islands of the U.S.
Virgin Islands Planning Department
and Natural Resources
Charlotte Amalie
Nisky center, Suite 231
St. Thomas, VI 00802
(809) 774-3320
U.S. Geological Survey
District Chief
Water Resources Division
GPO Box 4424
San Juan, PR 00936
(Street Address:
GSA Center, Building 652
Highway 28, Pueblo Viejo)
(809) 783-4660
NFIP State Coordinator
Mr. Roy E. Adams, commissioner
Virgin Islands Department of
Planning and Natural Resources
Suite 231, Nisky center
Charlotte Amalie
St. Thomas, VI 00802
(809) 774-3320
VIRGINIA
Virginia State Department of
Environmental Quality
4900 cot Road
Glen Allen, VA 23060
(804) 527-5000
U.S. Geological Survey
Hydrologist-in-Charge
Virginia Office
Water Resources Division
3600 West Broad Street
Room 606
Richmond, VA 23230
(804) 771-2427
U.S. Department of Agriculture
Natural Resources Conservation
Service
1606 Santa Rosa Road
Suite 209
Richmond, VA 23229
(804) 287-1689
A3-17
NFIP State Coordinator
Mr. Roland B. Geddes, Director
Department of Conservation and
Historic Resources
203 Governor Street, Suite 206
Richmond; VA 23219
(804) 786-4356
WASHINGTON
Department of Ecology
P.O. Box 47600
Olympia, WA 98504-7600
(206) 407-6000
U.S. Geological Survey
District Chief
Water Resources Division
1201 Pacific Avenue, Suite 600
Tacoma, WA 98402
(206) 593-6510
U.S. Department of Agriculture
Natural Resources Conservation
Service
316 Boone Avenue
Suite 456
Spokane, WA 99201
(509) 353-2336
NFIP State Coordinator
Mr. Chuck Clark
Washington Department of Ecology
P.O. Box 47600
Olympia, WA 98504-7600
(206) 459-6168
WEST VIRGINIA
West Virginia Office of
Emergency Services
Room EB-80, Capitol Building
Charleston, WV 25305
(304) 348-5380
U.S. Geological Survey
District Chief
Water Resources Division
11 Dunbar Street
Charleston, WV 25301
(304) 347-5130
U.S. Department of Agriculture
Natural Resources Conservation
Service
75 High street, Rm. 301
Morgantown, WV 26505
(304) 291-4151
Appendix 3 -continued
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
Other Federal and State Agencies
NFIP State Coordinator
Mr. Carl Bradford, Director
West Virgin i a Office of
Emergency Services
Room EBI-80
Capitol Bui l ding
Charleston, WV 25305
(304) 348-5380
WISCONSIN
Department of Natural Resources
Dam Safety/Floodplain
Management Section
P.O. Box 7921
Madison, WI 53707
( 608) 266-2621
U.S. Geological Survey
District Chief ·
Water Resources Center
University of Wisconsin/Madison
1975 Willard Drive
Madison, WI 53706-4042
(608) 262-3577
U.S. Department of Agriculture
Natural Resources Conservation
Service
6515 Watts Road
Suite 200
Madison, WI 53719
(608) 264-5341
NFIP State Coordinator
Mr. Carroll D. Besandy, Secretary
Wisconsin Department of Natural
Resources
P.O. Box 7921
Madison, WI 53707
(608) 266-2121
WYOMING
Wyoming Emergency Management Agency
P.O. Box 1709
Cheyenne, WY 82003-1709
(307) 777-4900
U.S. Geological Survey
District Chief
Water Resources Division
P.O. Box 1125
Cheyenne, WY 82003
(Street Address:
2617 East Lincoln Way
Cheyenne, WY 82001
(307) 772-2153
A3-18
U.S. Department of Agriculture
Natural Resources Conservation
Service
Federal Office Building
100 East "B" Street
Casper, WY 82601
(307) 261-5231
NFIP State Coordinator
Mr. Joe Daly, Coordinator
Wyoming Emergency Management
Agency
P.O. Box 1709
Cheyenne, WY 82003
(307) 777-7566
Appendix 3 -continued
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
U.S. Army corps of Engineers
U.S. Army Corps of Engineers
Headquarters
20 Massachusetts Ave., NW
Washington, D.C. 20314-1000
Attn: CECW-PF
202/272-0169
U.S. Army Corps of Engineers
Lower Miss. Valley Division
P.O. Box 80
Vicksburg, MS 39181-0080
Attn: CELMV-PD-CM
601/634-5827
U.S. Army Corps of Engineers
Memphis District
167 North Main Street, B-202
Memphis, TN 38103-1894
Attn: CELMM-PD-M
901/544-3968
U.S. Army Corps of Engineers
New Orleans District
P.O. Box 60267
New Orleans, LA 70160-0267
Attn: CELMN-PD-FG
504/865-1121
U.S. Army Corps of Engineers
St. Louis District
1222 Spruce Street
St. Louis, MO
63103-2833
Attn: CELMS-PD-M
314/331-8483
U.S. Army Corps of Engineers
Vicksburg District
2101 North Frontage Road
Vicksburg, MS 39180-0060
Attn: CELMK-PD-FS
601/631-5416
U.S. Army Corps of Engineers
Missouri River Division
12565 West Center Road
Omaha, NE 68104-3869
Attn: CEMRD-PD-F
402/221-7273
U.S. Army Corps of Engineers
Kansas City District
700 Federal Building Kansas
City, MO 64106-2896
Attn: CEMRK-PD-P
816/426-3674
A3-19
U.S. Army Corps of Engineers
Omaha District
215 North 17th Street
Omaha, NE 68102-4978
Attn: CEMRO-PD-F
402/221-4596
U.S. Army Corps of Engineers
North Atlantic Division
90 Church Street
New York, NY 10007-2979
Attn: CENAD-PL-FP
212/264-7482
U.S. Army Corps ot Engineers
Baltimore District
Supervisor of Baltimore Harbor
P.O. Box 1715
Baltimore, MD 21201-1715
Attn: CENAB-PL-B
410/962-7608
U.S. Army Corps of Engineers
New York District, Planning
Division, Floodplain Management
Section
26 Federal Plaza
New York, NY 10278
Attn: CENAN-PL-FP
212/264-8870
U.S. Army Corps of Engineers
Norfolk District
Supervisor of Norfolk Harbor
803 Front Street
Norfolk, VA 23510-1096
Attn: CENAO-PL-FP
804/441-7779
U.S. Army Corps of Engineers
Philadelphia District
U.S. Customs House
2nd & Chestnut Streets
Philadelphia, PA 19106-2991
Attn: CENAP-PL-F
215/656-6516
U.S. Army Corps of Engineers
North Central Division
111 North Canal Street, 14th Floor
Chicago, IL 60606
Attn: CENCD-PD-FP
312/353-1279
Appendix 3 -continued
Federal Emergency Management Agency Offices
and Other Federal and State Agencies
u.s. Army Corps of Engineers
U.S. Army Corps of Engineers
Buffalo District, Planning Division,
Floodplain Management Section
1776 Niagara Street
Buffalo, NY 14207-3199
Attn: CENCB-PD-FP
716/879-4104
U.S. Army Corps of Engineers
Chicago District
111 North Canal Street
14th Floor
Chicago, IL 60606
Attn: CENCC-PD-R
312/353-6400
U.S. Army Corps of Engineers
Detroit District
477 Michigan Avenue
Detroit, MI 48226
Attn: CENCE-PD-PF
313/226-6773
U.S. Army Corps of Engineers
Rock Island District
P.O. Box 2004
Clock Tower Building
Rock Island, IL 61204-2004
Attn: CENCR-PD-F
309/788-4750
U.S. Army Corps of Engineers
St. Paul District
190 Phipps street East
St. Paul, MN 55101-1638
Attn: CENCS-PD-FS
612/290-5200
U.S. Army Corps of Engineers
New England Division
424 Trapelo Road
Waltham, MA 02254-9149
Attn: CENED-PL-B
617/647-8111
U.S. Army Corps of Engineers
North Pacific Division
333 Southwest 1st Avenue
Portland, OR 97204
Attn: CENPD-PL-FS
503/326-6021
U.S. Army Corps of Engineers
Alaska District
P.O. Box 898
Anchorage, AK 99506-0898
Attn: CENPA-EN-PL-FP
907/753-2504
U.S. Army Corps of Engineers
Portland District
P.O. Box 2946
Portland, OR 97208-2946
Attn: CENPP-PL-CF
503/326-6411
A3-20
U.S. Army Corps of Engineers
Seattle District
P.O. Box 3755
Seattle, WA 98124-2255
Attn: CENPS-EN-HH
206/764-3660
U.S. Army Corps of Engineers
Walla Walla District
Bldg. 602 City-county Airport
Walla Walla, WA 99362-9265
Attn: CENPW-PL-FP
509/522-6589
U.S. Army Corps of Engineers
Ohio River Division
P.O. Box 59
Louisville, KY 40201-0059
Attn: CEORD-PD-J
502/582-5782
U.S. Army Corps of Engineers
Huntington District
502 8th Street
Huntington,WV 25701-2070
Attn: CEORH-PD-S
304/529-5644
U.S. Army Corps of Engineers
Louisville District
P.O. Box 59
Louisville, KY 40201-0059
Attn: CEORL-PD-S
502/582-5742
U.S. Army Corps of Engineers
Nashville District
P.O. Box 1070
Nashville, TN 37202-1070
Attn: CEORN-ED-P
615/736-5055
U.S. Army Corps of Engineers
Pittsburgh District
William S. Moorehead Fed. Bldg.
1000 Liberty Avenue
Pittsburgh, PA 15222-4186
Attn: CEORP-PD-J
412/644-6924
U.S. Army Corps of Engineers
Pacific Ocean Division
Ft. Shafter, HI 96858-5440
Attn: CEPOD-ED-PH
808/438-7009
Appendix 3 -continued
Federal Eaergency Management Agency Offices
and Other Federal and State Agencies
u.s. Aray Corps of Engineers
U.S. Army Corps of Engineers
Charleston District
P.O. Box 919
Charleston, SC 29402-0919
Attn: CESAC-EN-PH
803/727-4263
U.S. Army Corps of Engineers
South Atlantic Division
611 South Cobb Drive
Marietta, GA 30060
Attn: CESAD-PD-A
404/421-5296
U.S. Army Corps of Engineers
Jacksonville District
P.O. Box 4970
Jacksonville, FL 32232-0019
Attn: CESAJ-PD-FP
904/232-2234
U.S. Army Corps of Engineers
Mobile District
P.O. Box 2288
Mobile, AL 36628-0001
Attn: CESAM-PD-P
205/694-3879
U.S. Army Corps of Engineers
Savannah District
P.O. Box 889
Savannah, GA 31402-0889
Attn: CESAS-PD-F
912/652-5822
U.S. Army Corps of Engineers
Wilmington District
P.O. Box 1890
Wilmington, NC 28402-1890
Attn: CESAW-PD-F
910/251-4822
U.S. Army Corps of Engineers
South Pacific Division
Room 720
630 Sansome Street
San Francisco, CA 94111-2206
Attn: CESPD-PD-P
415/705-2427
U.S. Army Corps of Engineers
Los Angeles District
P.O. Box 2711
Los Angeles, CA 90053-2325
Attn: CESPL-PD-WF
213/894-5450
A3-21
U.S. Army Corps of Engineers
Sacramento District
1325 G street
Sacramento, CA 95814-4794
Attn: CESPK-PD-F
916/557-6700
U.S. Army Corps of Engineers
San Francisco District
211 Main Street
San Francisco, CA 9410S-1905
Attn: CESPN-PE-W
415/744-3029
U.S. Army Corps of Engineers
Southwestern Division
1114 Commerce Street
Dallas, TX 75242-0216
Attn: CESWD-PL-M
214/767-2310
U.S. Army Corps of Engineers
Albuquerque District
P.O. Box 1580
Albuquerque, NM 87103-1580
Attn: CESWA-ED-PH
505/766-2635
U.S. Army Corps of Engineers
Fort Worth District
P.O. Box 17300
Fort Worth, TX 76102-0300
Attn: CESWF-PL-F
817/334-3207
U.S. Army Corps of Engineers
Galveston District
P.O. Box 1229
Galveston, TX 77553-1229
Attn: CESWG-PL-P
409/766-3023
U.S. Army Corps of Engineers
Little Rock District
P.O. Box 867
Little Rock, AR 72203-0867
Attn: CESWL-PL-F
501/378-5611
U.S. Army Corps of Engineers
Tulsa District
P.O. Box 61
Tulsa, OK 74121 0061
Attn: CESWT-PL-GF
918/581-7896
Appendix 3 -continued
Federal Baergency Manageaent Agency Off ice•
and Other Federal and State Agencie•
River Basin Commissions
Delaware Ri ver Basin Commission
25 State Police Drive
Box 7360
West Trenton, NJ 08628
609/883-9500
Susquehanna River Basin Commission
1721 North Front Street
Harrisburg, PA
717/238-042 2
A3-22
Appendix 4
state Hydrology Reports
ALABAMA
Olin, D.A. and Bingham, R.H., 1982, Synthesized flood frequency of urban streams
in Alabama: U.S. Geological Survey Water-Resources Investigations 82-683.
Olin, D.A., 1984, Magnitude and frequency of floods in Alabama: U.S. Geological
Survey Water-Resources Investigations 84-4191.
ALASKA
Lamke, R.D., 1978, Flood characteristics of Alaskan streams: U.S. Geological
Survey Water-Resources Investigations 78-129.
ARIZONA
Eychaner, J.H., 1984, Estimation of magnitude and frequency of floods in Pima
County, Arizona, with comparisons of alternative methods: U.S. Geological Survey
Water-Resources Investigations 84-4142.
ARKANSAS
Neely, B.L., Jr., 1986, Magnitude and frequency of floods in Arkansas: U.S.
Geological Survey Water-Resources Investigations 86-4335.
CALIFORNIA
Waananen, A.O., and Crippen, J.R., 1977, Magnitude and frequency of floods in
California: U.S. Geological Survey Water-Resources Investigations 77-21 (PB-272
510/AS).
COLORADO
Hedman, E.R., Moore, D.O. and Livingston, R.K., 1972, Selected streamflow
characteristics as related to channel geometry of perennial streams in Colorado:
U.S. Geological Survey Open-File Report.
Kircher, J.E., Choquette, A.F., and Richter, B.D., 1985, Estimation of natural
streamflow characteristics in Western Colorado: U.S. Geological Survey Water-
Resources Investigations 85-4086.
Livingston, R.K., 1980, Rainfall-runoff modeling and preliminary regional flood
characteristics of small rural watersheds in the Arkansas River Basin in
Colorado: U.S. Geological Survey Water-Resources Investigations 80-112 (NTIS).
Livingston, R.K., and Minges, D.R., 1987, Techniques for estimating regional
flood characteristics of small rural watersheds in the plains regions of eastern
Colorado: U.S. Geological Survey Water-Resources Investigations 87-4094.
McCain, J.R., and Jarrett, R.D., 1976, Manual for estimating flood
characteristics of natural flow streams in Colorado: Colorado Water Conservation
Board, Technical Manual No. 1.
A4-l
CONHECTICUT
Appendix 4 -continued
State Hydrology Reports
Weiss, L.A., 1975, Flood flow formula for urbanized and non-urbanized areas of
Connecticut: Watershed Management Symposium of ASCE Irrigation and Drainage
Division, August 11-13, 1975, pp. 658-675.
DELAWARE
Simmons, R.H., and Carpenter, D.H., 1978, Technique for estimating the magnitude
and frequency of floods in Delaware: U.S. Geological Survey Water-Resources
Investigations Open-File Report 78-93.
DISTRICT OF COLUMBIA
None listed
FLORIDA
Bridges, w.c., 1982, Technique for estimating the magnitude and frequency of
floods on natural-flow streams in Florida: U. s. Geological Survey Water-Resources
Investigations Open-File Report 82-4012.
Franklin, M.A ., 1984, Magnitude and frequency of floods from urban streams in
Leon County, Florida: U.S . Geological Survey Water-Resources Investigations
84-4004.
Lopez, M.A., and Woodham, W.M., 1982, Magnitude and frequency of floods on small
urban watersheds in the Tampa Bay area, west-central Florida: U.S . Geological
Survey Water-Resources Investigations 82-42.
GEORGIA
Inman, E.J., 1983, Flood-frequency relations for urban streams in metropolitan
Atlanta, Georgia: U.S. Geological Survey Water-Resources Investigations
83-4203.
Price, M., 1979, Floods in Georgia, magnitude and frequency: U.S. Geolog i cal
Survey Water-Resources Investigations 78-137 (PB-80 146 244).
BAWA II
Matsuoka, I., 1978, Flow characteristics of streams in Tutuila, American Somoa:
U.S. Geological Survey Open-File Report 78-103.
Nakahara, R.H ., 1980, An analysis of the magnitude and frequency of floods on
Oahu, Hawaii : U.S. Geological Survey Water-Resources Investigations 80-45
(PB-81 109 902).
A4-2
IDAHO
Appendix 4 -continued
State Hydrology Reports
Harenberg, W.A., 1980, Using channel geometry to estimate flood flows at ungaged
sites in Idaho: U.S. Geological Survey Water-Resources Investigations 80-32
(PB-81 153 736).
Kjelstrom, L.C., and Moffatt, R.L., 1981, Method of estimating flood-frequency
parameters for streams in Idaho: U.S. Geological Survey Open-File Report 81-909.
Thomas, C.A., Harenburg, W.A., and Anderson, J.M., 1973, Magnitude and frequency
of floods in small drainage basins in Idaho: U. s. Geological Survey Water-
Resources Investigations 7-73 (PB-222 409).
ILLINOIS
Allen, H.E., Jr., and Bejcek, R.M., 1979, Effects of urbanization on the
aagnitude and frequency of floods in northeastern Illinois: u. s. Geological
Survey Water-Resources Investigations 79-36 (PB-299 065/AS).
Curtis, G.W., 1987, Technique for estimating flood-peak discharges and
frequencies on rural streams in Illinois: U.S. Geological Survey Water-Resources
Investigations 87-4207.
IHDIAHA
Glatfelter, D.R., 1984, Technique for estimating the magnitude and frequency of
floods in Indiana: U.S . Geological Survey Water-Resources Investigations 84-4134.
IOWA
Lara, o., 1978, Effects of urban development on the flood flow characteristics
of Walnut Creek basin, Des Moines metropolitan area, Iowa: U.S. Geological Survey
Water-Resources Investigations 78-11 (PB-284 093/AS).
KAH SAS
Clement, R.W., 1987, Floods in Kansas and techniques for estimating their
magnitude and frequency: U.S. Geological Survey Water-Resources Investigations
87-4008 .
Hedman, E.R., Kastner, W.M., and Hejl, H.R., 1974, Selected streamflow
characteristics as related to active-channel geometry of streams in Kansas:
Kansas Water Resources Board Technical Report No. 10.
Peek, C.O., and Jordan, P.R., 1978, Determination of peak discharge from rainfall
relations for urbanized basins, Wichita, Kansas: U.S. Geological Survey Open-File
Report 78-974.
KENTUCKY
Choquette, A.F., 1987, Regionalization of peak discharges for streams in
Kentucky: U.S. Geological Survey Water-Resources Investigations 87-4029.
A4-3
LOUISIANA
Appendix 4 -continued
State Hydrology Reports
Lee, F.N., 1985, Floods in Louisiana, Magnitude and Frequency, Fourth Edition:
Department of Transportation and Development, Water Resources Technical Report
No. 36.
Lowe, A.S., 1979, Magnitude and frequency of floods in small watersheds in
Louisiana: Louisiana Department of Transportation and Development, Office of
Highways, Research Study No. 65-2H.
MAI HE
Morrill, R.A ., 1975, A technique for estimating the magnitude and frequency of
floods in Maine: U.S. Geological Survey Open-File Report.
MARYLAND
Carpenter, D.H ., 1980, Technique for estimating magnitude and frequency of floods
in Maryland: U .S. Geological Survey Water-Resources Investigations Open-File
Report 80-1016.
MASSACHUSETTS
Wandle, S .W., 1983, Estimating peak discharges and frequencies of small rural
streams in Massachusetts: U.S. Geological Survey Water-Supply Paper 2214.
MICHIGAN
Holtschlag, D.J., and Croskey, H.M., 1984, Statistical models for estimating flow
characteristics of Michigan streams: U.S. Geological Survey Water-Resources
Investigat i ons 84-4270.
MINNESOTA
Jacques, J .E., and Lorenz, D.L., 1987, Techniques for estimating the magnitude
and frequency of floods in Minnesota: U.S. Geological Survey Water-Resources
Investigations 87-4170.
MISSISSIPPI
Colson, B.E ., and Hudson, J.W., 1976, Flood frequency of Mississippi streams:
Mississippi State Highway Department .
MISSOURI
Becker, L.D ., 1986, Techniques for estimating flood-peak discharges for urban
streams in Mi ssouri: U.S. Geological Survey Water-Resources Investigations Report
86-4322.
Hauth, L.D ., 1974, A technique for estimating the magnitude and frequency of
Missouri floods: U.S. Geological Survey Open-File Report.
A4-4
MISSOURI continued
Appendix 4 -continued
state Hydrology Reports
Spencer, D.W., and Alexander, T.W., 1978, Techniques for estiaating the magnitude
and frequency of floods in St. Louis County, Missouri: U.S. Geological Survey
Water-Resources Investigations 78-139 (PB-298 245/AS).
MOHTAHA
omang, R.J., 1983, Mean annual runoff and peak flow estiaates based on channel
geoaetry of streams in southeastern Montana: U.S. Geological Survey Water-
Resources Investigations Report 82-4092.
omang, R.J., Parrett, c ., and Hull, J.A., 1986, Methods of estimating magnitude
and frequency of floods in Montana based on data through 1983: U.S . Geological
Survey Water-Resources Investigations Report 86-4027.
Parrett, c., 1983, Mean annual runoff and peak flow estiaates based on channel
geoaetry of streams in northeastern and western Montana: U.S. Geological Survey
Water-Resources Investigations Report 83-4046.
Parrett, c., Hull, J.A., andOmang, R .J., 1987, Revised techniques for estimating
peak discharges from channel width in Montana: U.S. Geological Survey Water-
Resources Investigations 87-4121.
NEBRASKA
Beckman, E.W., 1976, Magnitude and frequency of floods in Nebraska: U.S.
Geological Survey Water-Resources Investigations 76-109 (PB-260 842/AS).
NEVADA
Moore, D.O., 1974, Estimating flood discharges in Nevada using channel-geometry
aeasureaents: Nevada State Highway Department Hydrologic Report No. 1.
Moore, D.O., 1976, Estimating peak discharges from small drainages in Nevada
according to basin areas within elevation zones: Nevada State Highway Department
Hydrologic Report No. 3.
NEW HAMPSHIRE
LeBlanc, D.R., 1978, Progress report on hydrologic investigations of small
drainage areas in New Haapshire--Preliainary relations for estimating peak
discharges on rural, unregulated streaas: U.S. Geological Survey Water-Resources
Investigations 78-47 (PB-284 127/AS).
HEW JERSEY
Stankowski, S.J., 1974, Magnitude and frequency of floods in New Jersey with
effects of urbanization: New Jersey Department of Environmental Protection
Special Report 38.
Velnick, Anthony J. and Laskowski, Stanley L., 1979, Technique for estiaating
depth of 100-year flood in New Jersey: Open-File Report 79-419.
A4-5
HEW MEXICO
Appendix 4 -continued
State Hydrology Reports
Hejl, H.R., Jr., 1984, Use of selected basin characteristics to estimate mean
annual runoff and peak discharges for ungaged streaas in drainage basins
containing strippable coal resources, northwestern Hew Mexico: U.S. Geological
Survey Water-Resources Investigations 84-4264.
Scott, A.G., and Kunkler, J.L., 1976, Flood discharges of streaas in Hew Mexico
as related to channel geometry: U.S. Geological Survey Open-File Report.
Waltmeyer, S.D., 1986, Techniques for estimating flood-flow frequency for
unregulated streams in Hew Mexico: U. s. Geological Survey Water-Resources
Investigations 86-4104.
HEW YORK
Lomia, Richard, 1991, Regionalization of flood discharges for rural, unregulated
streaas in Hew York, excluding Long Island: U. s. Geological Survey Water-
Resources Investigations Report 90-4197.
HORTH CAROLINA
Gunter, H.C., Mason, R.R., and Stamey, T.C., 1987, Magnitude and frequency of
floods in rural and urban basins of Horth Carolina: U.S. Geological Survey Water-
Resources Investigations 87-4096.
Martens, L.S., 1968, Flood inundation and effects of urbanization in metropolitan
Charlotte, North Carolina: U.S. Geological Survey Water-Supply Paper 1591-C.
Putnam, A.L., 1972, Effect of urban development on floods in the Piedmont
province of North Carolina: U.S. Geological Survey Open-File Report.
NORTH DAKOTA
Crosby, O.A., 1975, Magnitude and frequency of floods in small drainage basins
of Horth Dakota: U.S. Geological Survey Water-Resources Investigations 19-75
(PB-248 480/AS).
OHIO
Roth, D.K., 1985, Estimation of flood peaks from channel characteristics in Ohio:
U.S. Geological Survey Water-Resources Investigations Report 85-4175.
Sherwood, J.M., 1986, Estimating peak discharges, flood voluaes, and hydrograph
stages of small urban streams in Ohio: U.S. Geological Survey Water-Resources
Investigations Report 86-4197.
Webber, E.E., and Bartlett, W.P., Jr., 1977, Floods in Ohio magnitude and
frequency: State of Ohio, Department of Natural Resources, Division of Water,
Bulletin 45.
Webber, E.E., and Roberts, J.W., 1981, Floodflow characteristics related to
channel geometry in Ohio: U .S. Geological Survey Open-File Report 81-1105.
A4 -6
OKLAHOMA
Appendix 4 -continued
State Hydrology Reports
Sauer, V.B., 1974, An approach to estimating flood frequency for urban areas in
Oklahoma: U.S. Geological Survey Water-Resources Investigations 23-74
(PB-235 307/AS).
Tortorelli, R.L., and Bergman, D.L., 1984, Techniques for estimating flood peak
discharge for unregulated streams and streams regulated by small floodwater
retarding structures in Oklahoma: U.S. Geological Survey Water-Resources
Investigations 84-4358.
OREGON
Harris, D.D., and Hubbard, L.E., 1982, Magnitude and frequency of floods in
eastern Oregon: U.S. Geological Survey Water-Resources Investigations 82-4078.
Harris, D.D., Hubbard, L.E., and Hubbard, L.L., 1979, Magnitude and frequency of
floods in western Oregon: U.S. Geological Survey Open-File Report 79-553.
Laenen, Antonius, 1980, Storm runoff as related to urbanization in the Portland,
Oregon-Vancouver, Washington, area: U. s. ·Geological Survey Water-Resources
Investigations Open-File Report 80-689.
PEHHSYLVAHIA
Bailey, J.F., Thomas, w.o., Jr., Wetzel, K.L., and Ross, T.J., 1987, Estimation
of flood-frequency characteristics and the effects of urbanization for streaas
in the Philadelphia, Pennsylvania, area: U.S. Geolog+cal Survey Water-Resources
Investigations 87-4194. ·
Flippo, H.N., Jr., 1977, Floods in Pennsylvania: A manual for estimation of their
aagnitude and frequency: Pennsylvania Department of Environmental Resources
Bulletin No. 13.
PUERM RICO
Lopez, M.A., Colon-Dieppa, E., and Cobb, E.D., 1978, Floods in Puerto Rico:
magnitude and frequency: U.S. Geological Survey Water-Resources Investigations
78-141 (PB-300 855/AS).
RHODE ISLAND
Johnson, C.G., and Laraway, G.A., 1976, Flood magnitude and frequency of saall
Rhode Island streaas--Preliainary estimating relations: U.S. Geological Survey
Open-File Report.
SOUTH CAROLINA
Whetstone, B.H., 1982, Floods in South Carolina--Techniques for estiaating
magnitude and frequency of floods with compilation of flood data: U.S. Geological
survey Water-Resources Investigations 82-1.
A4-7
SOUTH DAKOTA
Appendix 4 -continued
State Hydrology Reports
Becker, L.D., 1974, A aethod for eatiaating the aagnitude and frequency of floods
in South Dakota: U.S. Geological Survey Water-Resources Investigations 35-74
(PB-239 831/AS).
Becker, L.D., 1980, Techniques for eatiaating flood peaks, voluaea, and
hydrographa on aaall atreaaa in South Dakota: U.S. Geological Survey Water-
Resources Investigations 80-80 (PB-81 136 145).
TERNES SEE
Neely, B.L., Jr., 1984, Flood frequency and atora runoff of urban areas of
Meaphia and Shelby County, Tennessee: U.S. Geological Survey Water-Resources
Investigations 84-4110.
Randolph, W.J., and Gamble, C.R., 1976, A technique for estimating magnitude and
frequency of floods in Tennessee: Tennessee Department of Transportation.
Robbins, C.H., 1984, Synthesized flood frequency of small urban atreaaa in
Tennessee: U .S. Geological Survey Water-Resources Investigations 84-4182.
Wibben, H.C., 1976, Effects of urbanization on flood characteristics in
Kaahville-Davidaon County, Tennessee: U.S. Geological Survey Water-Resources
Investigations 76-121 (PB-266 654/AS).
TEXAS
Land, L.F., Schroeder, E.E., and Hampton, B.B., 1982, Techniques for estiaating
the aagnitude and frequency of floods in the Dallas-Fort Worth Metropolitan Area,
Texas: U.S. Geological Survey Water-Resources Investigations 82-18.
Liscum, F., and Massey, B.c., 1980, Techniques for estiaating the aagnitude and
frequency of floods in the Houston, Texas aetropolitan area: U.S. Geological
Survey Water-Resources Investigations 80-17 (ADA-089 495).
Schroeder, E.E., and Massey, B.C., 1977, Techniques for estimating the aagnitude
and frequency of floods in Texas: U.S. Geological Survey Water-Resources
Investigations Open-File Report 77-110.
Veenhuis, J.E., and Garrett, D.G., 1986, The effects of urbanization on floods
in the Austin aetropolitan area, Texas: U.S. Geological Survey Water-Resources
Investigations 86-4069.
UTAH
Fields, F.K., 1974, Eatiaating atreaaflow characteristic• for atreaaa in Utah
using selected channel-geoaetry paraaetera: U.S. Geological Survey Water-
Resources Investigations 34-74 (PB-·241 541/AS).
Thomas, B.E., and Lindskov, K.L., 1983, Methods for eatiaating peak discharges
and flood boundaries of atreaaa in Utah: U.S. Geological Survey Water-Resources
Investigations 83-4129.
A4-8
VERMONT
Appendix 4 -continued
State Hydrology Reports
Johnson, C.G., and Tasker, G.D., 1974, Flood magnitude and frequency of Vermont
Streams: U.S. Geological Survey Open-File Report 74-130.
VIRGIN ISLANDS
None listed
VIRGINIA
Anderson, D.G., 1970, Effects of urban development on floods in Northern
Virginia: U.S. Geological Survey Water-Supply Paper 2001-C.
Miller, E.M., 1978, Technique for estimating the magnitude and frequency of
floods in Virginia: U.S. Geological Survey Water-Resources Investigations Open-
File Report 78-5.
WASHINGTON
Cummans, J.E., Collins, M.R., and Nassar, E.G., 1974, Magnitude and frequency of
floods in Washington: u.s. Geological Survey Open-File Report 74-336.
Haushild, W.L., 1978, Estimation of floods of various frequencies for the small
ephemeral streams in eastern Washington: U.S. Geological Survey Water-Resources
Investigations 79-81.
WEST VIRGINIA
Runner, G.S., 1980, Technique for estimating the magnitude and frequency of
floods in West Virginia: U.S. Geological Survey Open-File Report 80-1218.
WISCONSIN
Conger, D.H., 1980, Techniques for estimating magnitude and frequency of floods
for Wisconsin streams: U.S. Geological Survey Water-Resources Investigations
Open-File Report 80-1214.
Conger, D.H., 1986, Estimating magnitude and frequency of floods for ungaged
urban streams in Wisconsin: U.S. Geological Survey Water-Resources Investigations
Report 86-4005.
WYOMING
Craig, G.S., Jr., and Rankl, J.G., 1977, Analysis of runoff from small drainage
basins in Wyoming: U.S. Geological Survey Water-Supply Paper 2056.
Lowham, H.W., 1976, Techniques for estimating flow characteristics of Wyoming
streams: U.S. Geological Survey Water-Resources Investigations 76-112
(PB-264 224/AS).
A4-9
Appendix 5
Manning's "n" Values
The value of "n" may be computed by
where: basic "n" value for a straight, uniform, smooth channel
value added to correct for the effect of surface
irregularities
value added for variation in the shape and size of the
channel cross section
value added for obstructions
value added for vegetation and flow conditions
correction factor for meandering of the channel
Proper values of I1o to n 4 and m5 may be selected from the following table
according to the given conditions:
Channel conditions Values
Earth 0 .020
Material Rock cut 0 .025
involved no
Fine gravel 0 .024
Coarse gravel 0 .028
Smooth 0 .000
Degree of Minor 0.005
irregularity n ,
Moderate 0 .010
Severe 0 .020
Gradual 0 .000
Variations of
channel cross Alternating occasionally n , 0.005
section
Alternating frequently 0 .010-0.015
Negligible 0 .000
Relative Minor 0. 010-0. 015
effect of na
obstructions Appreciable 0 .020-0 .030
Severe 0 .040-0 .060
Low 0 . 005--0 . 010
Medium 0 .010--0 .025
Vegetation n,
High 0 .025--0 .050
Very high 0 .050-0.100
Minor 1.000
Degree of Appreciable m, 1 .150 meandering
Severe 1 .300
REFERENCE
1. Chow, Ven Te, Ph.D.: "Open-Channel Hydraulics," McGraw-Hill Book Company,
New York, 1959, pp. 106-114.
The computed "n" values should be compared with the typical "n" values from the
following pages, or with those in the U.S. Geological Survey Report (Reference
2) or the Federal Highway Administration Report (Reference 3).
AS-1
Appendix 5 -continued
Manning's "n" Values
Type of channel and description Minimum Normal Maximum
A. CLOSED CoNDUITS FLOWING PARTLY FULL
A-1. Metal
a. Brass, smooth
b. Steel
1. Lockbar and welded
2. Riveted and spiral
c. Cast iron
1. Coated
2. Uncoated
d . Wrought iron
1. Black
2. Galvanized
e. Corrugated metal
1. Subdrain
2. Storm drain
A-2. Nonmetal
a. Lucite
b. Glass
c. Cement
1. Neat, surface
2. Mortar
d. Concrete
l. Culvert, straight and free of d ebris
2. Culvert with bends, connections,
and some d ebris
3. Finished
4. Sewer with manholes, inlet , etc .,
straight
5. Unfinished , steel form
6. Unfinished , smooth wood form
7. Unfinished, rough wood form
e. Wood
1. Stave
2. Laminated, treated
f. Clay
1. Common drainage tile
2. Vitrified sewer
3. Vitrified sewer with manholes, inlet,
etc.
4. Vitrified subdrain with open joint
g. Brickwork
1. Glazed
2. Lined with cement mortar
h. Sanitary sewers coated with sewage
slimes, with bend s and connections
i. Paved invert, sewer, smooth bottom
j. Rubble masonry, cemented
AS-2
0 .009
0 .010
0 .013
0 .010
0 .011
0.012
0 .013
0.017
0.021
0 .008
0 .009
0 .010
0 .011
0.010
0 .011
0.011
0 .013
0 .012
0.012
0.015
0 .010
0 .015
0 .011
0.011
0 .013
0.014
0 .011
0 .012
0 .012
0 .016
0 .018
0 .010
0 .012
0.016
0 .013
0.014
0.014
0 .016
0 .019
0.024
0 .009
0.010
0 .011
0.013
0 .011
0.013
0 .012
0.015
0.013
0.014
0 .017
0 .012
0 .017
0.013
0.014
0.015
0.016
0.013
0.015
0.013
0 .019
0 .025
0 .013
0 .014
0 .017
0 .014
0 .016
0.015
0 .017
0 .021
0.030
0.010
0 .013
0 .013
0.015
0.013
0 .014
0.014
0.017
0 .014
0 .016
0.020
0 .014
0 .020
0.017
0.017
0 .017
0.018
0.015
0.017
0.016
0 .020
0 .030
Appendix 5 -continued
Manning's "n" Values
Type of channel and description Minimum Normal Maximum
B. LINED OR BUILT-UP CHANNELS
B-1. Metal
a. Smooth steel surface
1. Unpainted 0 .011 0.012 0.014
2. Painted 0 .012 0 .013 0 .017
b. Corrugated 0 .021 0 .025 0 .030
B-2. Nonmetal
a. Cement
1. Neat, surface 0 .010 0 .011 0 .013
2. Mortar 0 .011 0 .013 0 .015
b. Wood
1. Planed, untreated 0 .010 0 .012 0.014
2. Planed, creosoted 0 .011 0 .012 0 .015
3. Unplaned 0 .011 0 .013 0 .015
4. Plank with battens 0 .012 0 .015 0.018
5. Lined with roofing paper 0.010 0 .014 0 .017
c. Concrete
1. Trowel finish 0 .011 0 .013 0 .015
2. Float finish 0.013 0.015 0.016
3. Finished, with gravel on bottom 0 .015 0 .017 0.020
4. Unfinished 0 .014 0.017 0 .020
5. Gunite, good section 0.016 0 .019 0.023
6. Gunite, wavy section 0 .018 0 .022 0 .025
7. On good exc a vated rock 0 .017 0 .020
8. On irregular excav ated rock 0 .022 0.027
d. Concrete bottom float finished with
sides of
1. Dressed stone in mortar 0 .015 0 .017 0 .020
2. Random stone in morta r 0.017 0 .020 0.024
3 . Cement rubble masonry, plastered 0 .016 0 .020 0 .024
4. Cement rubble masonry 0.020 0 .025 0 .030
5. Dry rubble or riprap 0.020 0 .030 0.035
e. Gravel bottom with sides of
1. Formed concrete 0.017 0.020 0 .025
2. Random stone in mortar 0.020 0 .023 0.026
3. Dry rubble or riprap 0.023 0 .033 0 .036
J. Brick
1. Glazed 0 .011 0.013 0.015
2. In cement mortar 0.012 0.01& 0.018
g. Masonry
1. Cemented rubble 0 .017 0 .025 0.030
2. Dry rubble 0 .023 0 .032 0 .035
h. Dressed ashlar 0.013 0.015 0 .017
i. Asphalt
1. Smooth 0 .013 0 .013
2. Rough 0.016 0 .016
j. Vegeta.l lining 0 .030 ..... 0 .500
~
AS-3
Appendix 5 -continued
Manning's "n" Values
Type of channel and description Minimum Normal Maximum
C. E:xCAV ATED OR DREDGED
a. Earth, straight and uniform
1. Clean, recently completed
2. Clean, after weathering
3. Gravel, uniform section, clean
4. With short grass, few weeds
b. Earth, winding and sluggish
1. No vegetation
2. Grass, some weeds
3 . Dense weeds or aquatic plants m
deep channels
4. Earth bottom and rubble sides
5 . Stony bottom and weedy banks
6. Cobble bottom and clean sides
c. Dragline-excavated or dredged
1. No vegetation
2. Light brush on banks
d. Rock cuts
1. Smooth and uniform
2. Jagged and irregular
e. Channels not maintained, weeds and
brush uncut
1. Dense weeds, high as flow depth
2. Clean bottom, brush on sides
3. Same, highest stage of flow
4. Dense brush, high stage
D. NATURAL STREAMS
D-1. Minor streams (top width at flood stage
<100 ft)
a. Streams on plain
1. Clean, straight, full stage, no rifts or
deep pools
2. Same as above, but more stones and
weeds
3 . Clean, winding, some pools and
shoals
4. Same as above, but some weeds and
stones
5. Same as above, lower stages, more
ineffective slopes and sections ..
6 . Same as 4, but more stones
7. Sluggish reaches, weedy, deep pools
8. Very weedy reaches, deep pools, or
fioodways with heavy stand of tim-
ber and underbrush
AS-4
0 .016
0 .018
0 .022
0 .022
0.023
0 .025
0 .030
0 .028
0 .025
0.030
0.025
0 .035
0.025
0.035
0 .050
0 .040
0 .045
0.080
0.025
0 .030
0 .033
0 .035
0.040
0.045
0.050
0 .075
0.018
0.022
0.025
0.027
0 .025
0 .030
0 .035
0.030
0.035
0.040
0 .028
0.050
0.035
0 .040
0 .080
0.050
0.070
0 .100
0.030
0 .035
0 .040
0 .045
0.048
0 .050
0.070
0 .100
0 .020
0 .025
0.030
0 .033
0 .030
0 .033
0 .040
0 .035
0 .040
0 .050
0 .033
0.060
0 .040
0 .050
0.120
0.080
0 .110
0 .140
0 .033
0 .040
0 .045
0 .050
0.055
0 .060
0 .080
0 .150
Appendix 5 -continued
Manning's "n" Values
Type of channel and description Minimum Normal Maximum
b. Mountain strea ms, no vegetation in
channel, banks usually steep, trees
and brush along banks submerged at
high stages
1. Bottom: gra vels, cobbles, and few
boulders
2. Bottom : cobbles with large boulders
D-2. Flood plains
a. Pasture, no brush
1. Short grass
2 . High grass
b. Cultivated areas
1. No crop
2 . Mature row crops
3 . Mature field crops
c. Brush
1. Scattered brush, he1wy weeds
2. Light brus h and trees, in winter
3. Light brush and trees, in summer
4. Medium to dense brush, in winter
5. Medium to dense brush, in summer
d. Trees
1. Dense willows, summer, straight
2. Cleared land with tree stumps, no
sprouts
0 .030
0 .040
0 .025
0.030
0 .020
0 .025
0.030
0 .035
0.035
0 .040
0 .045
0.070
0 .110
0 .030
3. Same as above, but with heavy 0 . 050
growth of sprouts
4. Heavy stand of timber, a few down 0 .080
trees, little undergrowth, flood stage
below branches
5. Same as above, but with flood stage 0 .100
reaching branches
D-3. Major streams (top width at flood stage
>100 ft). Then value is less than that
for minor streams of similar description,
because banks offer less effective resistance.
a. Regular section with no boulders or
brush
b. Irregular and rough section
REFERENCES
0.025
0 .035
0.040
0 .050
0.030
0 .035
0 .030
0 .035
0.040
0 .050
0.050
0 .060
0.070
0 .100
0 .150
0 .040
0 .060
0.100
0 .120
0 .050
0 .070
0.035
0 .050
0.040
0 .045
0 .050
0 .070
0 .060
0 .080
0 .110
0 .160
0 .200
0.050
0 .080
0 .120
O.lQO
0 .060
0.100
1. Chow, Ven Te, Ph.D.: "Open-Channel Hydralics," McGraw-Hill Book Company,
New York, 1959, pp. 106-114.
2. U.S. Geological Survey, Roughness Characteristics of Natural Channels,
Water-Supply Paper 1849, Washington, D.C., 1967.
3. U.S. Department of Transportation, Federal Highway Administration, Guide
for Selecting Manning's Roughness Coefficients for Natural Channels and
Floodplains, Report No. FHWA-TS-84-204, McLean, Virginia, April 1984.
A5-5
-------------
Appendix 6
QUICK-2 computer Program Manual
A6-1
Z-9V
Federal Emergency Management Agency
Computation of <Wate't ~u't{ace
EferJationi in t.Dpen Cfzanne[i
QUICK-2
Computation of Water Surface Blevationa in Open Channels
User's Guide
Pederal Bmergency Management Agency
1995
TABLE OF CONTENTS
Chapter 1: INTRODUCTION
Chapter 2: OVERVIEW ..
Chapter 3: GETTING STARTED
Chapter 4: TUTORIALS
Normal Depth . . . . . .
Changing Variables
Step-Backwater . . . . . . . .
Running HEC-2 with QUICK-2 Files
Rerunning Using Saved Cross-Section
Channel Capacity . . .
Rating Curve Plot . .
PLOT-2 . . . . . . . . .
Profile Plot . . .
Cross-Section Plot
Chapter 5: FORMULAS ....
Critical Depth .
Channel Capacity .
Normal Depth
Step-Backwater .
Files
1-1
2-1
3-1
. 4-1
. 4-2
4-6
4-9
4-18
4-19
4-21
4-22
4-23
4-23
4-24
. 5-1
5-2
5-4
5-5
. 5-6
Appendix 1: DEFINITION OF VARIABLES ............... A-1
QUICK-2 User's Guide Introduction
Chapter 1: Introduction
QUICK-2 is a user friendly program that assists in the computation of
flood Water Surface Elevations (WSEs) in open channels of all types. It
is much easier to use than the United States Army Corps of Engineers
(USACE) HEC-2 program. However, a QUICK-2 step-backwater file can also
be used, as is, with the HEC-2 program, which is also included in the
QUICK-2 package of programs. Therefore a HEC-2 output file can be
generated with a QUICK-2 input data file, without ever leaving the
QUICK-2 environment; and, without having to know how to set-up and run
the HEC-2 program. This version of QUICK-2 (Version 1.0) however, does
not perform hydraulic calculations through bridges or culverts.
QUICK-2 was primarily developed to accompany the FEMA technical
guidance manual titled, "MANAGING FLOODPLAIN DEVELOPMENT IN ZONE A
AREAS - A GUIDE FOR OBTAINING AND DEVELOPING BASE FLOOD ELEVATIONS."
That manual is intended to assist local community officials who are
responsible for administering and enforcing the floodplain management
requirements of the National Flood Insurance Program (NFIP) . The
purpose of that manual is to provide guidance for obtaining and
developing base flood (100-year) elevations (BFEs) where Special Flood
Hazard Areas (SFHAs) on a community's Flood Hazard Boundary Map (FHBM)
or Flood Insurance Rate Map (FIRM) have been identified and designated
as Zone A.
QUICK-2 will also be useful to community engineers, architect/engineer
firmi, developers, builders and others at the local level who may be
required to develop BFEs for use in Special Flood Hazard Areas.
This manual includes four other chapters: Overview, Getting Started,
Tutorials and Formulas. The Formulas section describes the "complex"
equations and methodologies used in the development of the program. An
Appendix is also included that contains a list of Definitions of the
variables shown on the screen and on the printouts.
To get started as quickly as possible in using QUICK-2 we
recommend that the user read the Overview and Getting
Started chapters; and then work through the Tutorials.
MINIMUM SYSTEM REQUIREMENTS
Random Access Memory (RAM}
Hard disk storage
Monitor
Printer (prints to LPTl)
Disk Operating System (DOS) -
1-1
512K
SOOK
Color or Monotone
Dot-matrix to LaserJet
Version 3.0 or higher
QUICK-2 User's Guide Overview
Chapter 2: Overview
V FOUR OPTIONS
This user friendly program computes:
• Critical Depth,
• Cross Section Capacity (Rating Curves),
• Normal Depth, and
• Step-Backwater Analysis (similar to the USACE HEC-2 program)
CRITICAL DEPTH: This option should be used to determine a Base Flood
Elevation (BFE) if a previous calculation using the Normal Depth option
computed a depth that was determined to be SUPERCRITICAL. Super
Critical depths are generally not accepted for use as BFEs.
CHANNEL CAPACITY: This option is used to determine a rating curve for
a cross section. The program computes a discharge based on the entered
depth. Repeating with other depths produces a rating curve. A BFE may
be determined by interpolation with the correct discharge.
NORMAL DEPTH: This is the usual option to use in determining BFEs. The
user should watch the "Flow Type" message to make sure that the
calculation is CRITICAL or SUBCRITICAL. Use Option 1 if SUPERCRITICAL.
STEP-BACKWATER: This option should be used to calculate BFEs if more
than one cross-section is warranted to cover the extent of the
property. Generally if the property parallels more than 500 feet of a
flooding source this option should be used.
V HANDLES "REGULAR" AND "IRREGULAR" SHAPED CROSS SECTIONS
The REGULAR shape cross-sections include:
• V-shape,
• Trapezoidal,
• Rectangular, and
• Circular
2-1
QUICK-2 Us er's Guide overview
For IRREGULAR cross-sections:
-up to 40 points can be input to describe the ground points
-Ground p oints are easily modified using the Insert or Delete Keys
-Encroachments or other changes in the floodplain are easily modeled
-An u nlimi ted number of cross sections may be modeled
In addition, ground points and other input variables for the irregular
shape cros s -sections can be saved to a file, for later use .
Y SINGLE SCREEN DATA INPUT, COMPUTATION AND OUTPUT
One of t he most user-friendly aspects of this program that sets i t
apart from many other computational programs is that all of the data
input, the computation, and the printing or plotting, is performed from
the same screen. You will not get lost in a maze of menus .
YGRAPm cs
• Cross-Sec tion Plots,
• Water Surface Elevation Profiles, and
• Rating Cu rve Plots
Cross sect ion plots and water surface elevation profiles from QUICK -2 's
step-backwater analysis can be viewed on the screen us i ng the USA CE
PLOT-2 p r ogram that comes with the QUICK-2 package of programs. The
channel capacity option of QUICK-2 can be used to generate r ating curve
plots of ·individual cross sections that can be viewed on screen and
printed. ·
Y AUTOMATIC ERROR CHECKING
This software is designed to virtually eliminate the need for user's
manuals. T he program incorporates error-checking routines and warning
messages t o alert the user to incorrect input data or potentially
incorrect output data . The program prompts the user for the required
input data so that there is no need to worry about which columns to put
data in; whether or not it needs to be left-justified, or right-
justified, e t c .
2-2
QUICK-2 User's Guide Overview
SPECIAL FEATURES OF QUICK-2
>»> Critic al Depth, Channel Capacity, and Normal Depth Options <«<
EASY VIEW: All of the input data is viewed on the same screen (and
changes can be made) before starting the computations
EASY CHANGE: After an initial calculation, the following parameters can
be changed, and the above options can be re-calculated in seconds:
Discharge
Base width or Diameter
Channel Stations
Channel Slope
Channel Side Slope
Manning's N
Ground Points
AUTO-SAVE: For irregular channels the program automatically stores all
the input variables to a file designated as "TEMP. XSC", which is stored
in the C:\QUICK2\DATA Directory.
RATING CURVES: A special feature of the Channel Capacity Option for
irregular channels is the Rating Curve Print Option . A rating curve
plot can be automatically generated with 20 computations of water
surface elevation versus discharge. The maximum elevation of the rating
curve will be just lower than the channel depth specified by the user.
The rating curve can be viewed on the screen and/or printed.
»» Step-Backwater Option ««
EASY VIEW: All of the input data is viewed on the same screen (and
changes can be made) before starting the computations
PRECISE: Balances the energy equation to within .01 foot.
COMPUTES CRITICAL DEPTH AUTOMATICALLY: After up to 40 energy balance
trials (without a balance) the program automatically computes critical
depth.
OUTPUT OPTIONS: Detailed and Summary printouts are available
AUTO-SAVE: The program automatically saves the first cross -section into
a file designated as TO.XSC, and subsequent cross-sections are saved
adding the Channel distance (XLCH) to the previous cross-section's file
name. Therefore, if we run 3 cross-sections that are 200 feet apart
their filenames will be: TO.XSC, T200.XSC, and T400.XSC. These 'files
are automatically stored in a directory named C:\QUICK2\DATA.
HEC-2 RUNS WITH QUICK-2 FILES: The backwater option also automatically
saves all of the cross-sections into a HEC -2 compatible file called
HEC2.DAT, which is stored in the C: \QUICK2 Directory . The QUICK-2
program is linked with the USACE HEC-2 program such that any backwater
computation that is run using QUICK-2 can also be run using the HEC-2
program within the QUICK-2 environment. The user does not need to have
any previous experience in running the HEC-2 model.
2-3
QUICK-2 User's Guide overview
AUTOMATIC ERROR CHECKS AND WARNING MESSAGES
ERROR CHECKS
Error checks prevent the user from continuing by re-prompting the user
for correct input data. The following are error checks performed
automatically by the program :
-Ground Point (GR) stations should be ~ncreasing
-Stations of the left and right bank should match a GR point
WARNING MESSAGES
Warning messages instruct the user that the program has had to modify
the input data in order to complete a calculation, or that the
completed calculation may not be valid. The following are warning
messages performed by the program:
Extended Cross Section
The computed water surf ace elevation is higher than one or both ends of
the cross-section, and the program automatically extended the end (s) of
the cross-section vertically to complete the computation .
Divided Flow
There is a ground point(s) within the cross-section which is higher
than the computed water surface elevation which is dividing the flow
within the cross-section .
No Energy Balance ... Computing Critical Depth
The program attempted up to 40 trial computations and could not arrive
at an energy balance; and therefore, critical depth is assumed to occur
at this cross-section.
Comoutinq Critical Deoth ... Critical Depth Assumed
Either the initial Starting Water Surface Elevation or an energy
balance between two cross sections occurred at an elevation for which
the f roude number or the index f roude number was equal to or greater
than 1. Thus, the computed water surface elevation is suspected of
being below the critical depth. Therefore the critical depth is
computed and compared to the previous calculated water surf ace
elevation. In this case the critical depth elevation was higher, and
thus Critical Depth is Assumed.
Computing Critical Depth ... Critical Depth Not Assumed
Sarne as above except, the critical depth is computed and compared to
the previous calculated water surface elevation; and, in this case the
critical depth elevation was lower, and thus Critical Depth is Not
Assumed.
2-4
QUICK-2 User's Guide
Chapter 3: Getting Started
This section provides you with
convenient installation and run
procedures that will enable you
to run the program from the hard
disk drive or the floppy disk drive.
Getting Started
HARD DISK INSTALLATION AND RUN PROCEDURE
To install and run QUICK-2 simply place the floppy disk in either your
"A" disk drive or your "B" disk drive.
For "A" Drive users: Type
For "B" Drive users: Type
A:\AQ2
B:\BQ2
and Press <Enter>
and Press <Enter>
Follow the screen message to start the program. That's it!
The program resides in a C:\QUICK2 directory. To run the program in the
future, just change to that directory and type Q2 and press <Enter>.
FLOPPY DISK INSTALLATION AND RUN PROCEDURE
To install and run QUICK-2 from the floppy disk drive simply place the
floppy disk in either your "A" disk drive or your "B'' disk drive .
For "A" Drive users:
For "B" Drive users:
Type
Type
A: \FAQ2
B:\FBQ2
and Press <Enter>
and Press <Enter>
Follow the screen message to start the program. That's it!
To run the program in the future, just place the disk in your floppy
drive, change to that directory and type Q2 and press <Enter>.
Although the program will run from the floppy disk drive it will run
much faster if installed and run on the hard disk drive.
REMINDER:
Entering and editing data, as well as moving around within the input
screens is performed using the Function keys, the Backspace Key and the
Enter Key. DO NOT USE THE CURSOR CONTROL KEYS (ARROW KEYS) FOR
ENTERING, DELETING, OR EDITING DATA.
3-1
Chapter 4: TUTORIALS
Normal Depth
Step-Backwater
Channel Capacity
PLOT-2
{TIME REQUIRED TO COMPLETE ALL THE TUTORIALS IS ABOUT ONE HOUR}
4-1
QUICK-2 User's Guide Normal Depth Tutorial
NORMAL DEPTH {Tutorial Time: 5 to 10 minutes}
After pressing Q2 and <Enter> to start the program you will come to
the Main Menu screen of QUICK-2 as shown below.
Critical Depth
Channel Capacity
Normal Depth
Step-Backwater
QUIT
QUICK - 2
MAIN MENU
Press
1
2
3
4
<F10>
1. Press 3 and then press <Enter> to start the Normal Depth Option.
Next you will see the Shape of Cross Section screen:
SHAPE OF CROSS SECTION
V -Ditch
Rectangular Channel
Trapezoidal Channel
Circular Channel
Irregular Channel
Press
v
R
T
c
Let's try the Trapezoidal Channel option.
2. Press T and then press <Enter> to perform a Normal Depth
calculation for a trapezoidal channel.
4-2
QUICK-2 User's Guide Normal Depth Tutorial
The next screen you will see is the Input I Output screen:
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) : 1 R Side Slope (H:V) : 1
Bottom Width (ft) Manning's n
Discharge (cfs) Depth (ft)
Slope (ft/ft)
OUTPUT VARIABLES
Area (sq ft) Wet Perimeter (ft)
Velocity Cft/s) Hyd Radius
Top Width (ft) Froude #
Flow Type
Enter Left Side Slope and Press <Enter> :1
<-Back Tab <F2> Main Menu <F7>
The program is currently prompting you to enter the Left Side Slope
(in terms of the Number of Horizontal feet (H) to every 1 foot
Vertical (H : 1). Let's say our left side slope is 3 to 1 (3:1).
3. Enter 3 and then Press <Enter>.
The next screen you will see is the Input / Output screen with a new
prompt:
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1
Bottom Width Cft)
Discharge Ccfs)
R Side Slope (H:V)
Manning's n
Depth (ft)
Slope (ft/ft)
Area (sq ft)
Velocity (ft/s)
lop Width (ft)
OUTPUT VARIABLES
Wet Perimeter (ft)
Hyd Radius
Froude #
Flow Type
: 1
Enter Right Side Slope and Press <Enter> :1
<-Back Tab <F2> Main Menu <F7>
Notice that the
3 has been entered
to the right of
"L Side Slope (H:V)"
The program is currently prompting you to enter the Right Side Slope
(in terms of the Number of Horizontal feet (H) to every 1 foot
Vertical (H : 1). Let's say our right side slope is 2 to 1 (2:1).
4. Enter 2 and then Press <Enter>.
4-3
QUICK-2 User's Guide
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1
Bottom Width (ft)
Discharge (cfs)
Slope (ft/ft)
R Side Slope CH:V) 2.0:1
Manning's n
Depth (ft)
OUTPUT VARIABLES
Area (sq ft)
Velocity (ft/s)
Top Width (ft)
Enter • •••••••••••••• •
<· Back Tab <F2>
Wet Perimeter (ft)
Hyd Radius
Froude #
Flow Type
and Press <Enter>
Main Menu <F7>
Normal Depth Tutorial
The program will continue to prompt you for input data.
Let's say our channel is 10 feet wide, with a Manning's n value of
0.035, the discharge is 300 cfs, and the channel slope is .005 ft/ft.
SCREEN PROMPT -"Enter Bottom Width and Press cEnter>"
5. Enter 10 and then Press <Enter>.
SCREEN PROMPT -"Enter Manning's n and Press cEnter>"
6. Enter .035 and then Press <Enter>.
SCREEN PROMPT -"Enter Discharge and Press cEnter>"
7. Enter 300 and then Press <Enter>.
SCREEN PROMPT -"Enter Slope and Press cEnter>"
8. Enter .005 and then Press <Enter>.
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1
Bottom Width (ft) 10.0
Discharge (cfs) 300
Slope (ft/ft) 0.0050
R Side Slope (H:V) 2.0:1
Manning's n 0.0350
Depth (ft) 0.00
OUTPUT VARIABLES
Area (sq ft)
Velocity (ft/s)
Top Width (ft)
Wet Perimeter (ft)
Hyd Radius
Froude #
Flow Type
11eg;n Calculations <Enter>
<· Back Tab <F2> Main Menu <F7>
4-4
After all the data
is input your screen
should look like this
QUICK-2 User's Guide Normal Depth Tutorial
To begin the calculation simply ...
9. Press <Enter>.
After a split second the screen should look like this:
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1 R Side Slope (H:V) 2.0:1
Bottom Width (ft) 10.0 Maming•s n 0.0350
Discharge (cfs) 300 Depth (ft) 3.27
Slope (ft/ft) 0.0050
OUTPUT VAR IABLES
Area (sq ft) 59.6 Wet Perimeter (ft) 27.7
Velocity (ft/s) 5.0 Hyd Radius 2.2
Top Width (ft) 26.4 Froude # 0.6
Flow Type SUBCR IT I CAL
Begin Calculations <Enter>
Print <F5>
<· Back Tab <F2> Main Menu <F7>
Notice that the Depth is no longer 0.00, but equals 3.27 feet, which
is the Normal Depth for this particular Trapezoidal cross-section. If
300 cfs represents the 100-year discharge, then the 100-year flood
depth would equal 3.27 feet. All of the output variables have also
been computed and listed.
10. To print the output simply Press the <FS> Function key.
The printed output is shown below.
QUICK - 2
NORMAL DEPTH
Trapezoidal Channel
I
Depth
I
v
INPUT VARIABLES
\ I 11 \\ n = O . 035
1
; 11
3:-o \ I 2-:o \ ____ !
Base Width = 10.0
= 0.0050 Slope
4-5
OUTPUT VARIABLES
Depth (ft)
Discharge (cf s)
Velocity (ft/s)
Top Width (ft)
3.27
300.0
5.04
26.4
0.59
SUBCRITICAL
Froude No.
Flow Type:
QUICK-2 User's Guide Normal Depth Tutorial
CHANGING THE VARIABLES
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1 R Side Slope (H :V) 2.0:1
Bottom Width (ft) 10.0 Manning's n 0.0350
Discharge (cfs) 300 Depth (ft) 3 .27
Slope (ft/ft) 0.0050
OUTPUT VARIABLES
Area (sq ft) 59.6 Wet Perimeter (ft) 27.7
Velocity ( ft/s) 5.0 Hyd Radius 2.2
Top Width (ft) 26.4 Froude # 0.6
Flow Type SUBCR IT I CAL
Begin Calculations <Enter>
Print <F5>
<· Back Tab <F2> Main Menu <F7>
Let's say we want to run this calculation again but with a disch~rge
of 500 cfs instead of 300 cfs.
1. Press the Function Key <F2>
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1 R Side Slope (H :V) 2.0:1
Bottom Width (ft) 10.0 Manning's n 0.0350
Discharge (cfs) 300 Depth (ft) 3 .27
Slope (ft/ft) 0.0050
OUTPUT VARIABLES
Area (sq ft) 59.6 Wet Perimeter (ft) 27.7
Velocity (ft/s) 5.0 Hyd Radius 2.2
Top Width (ft) 26.4 Froude # 0.6
Flow Type SUBCRI Tl CAL
Entel" Slope mid Pr-esa <Entel">
<· Back Tab <F2> Main Menu <F7>
The above screen is what you should be looking at. The <1'2> key will
move the prompt backwards through all the variables. Note that since
we want to change the Discharge (from 300 to 500), we will need to
Press <F2> again to come to the Enter Discharge prompt. Follow the
steps as shown on the following page to rerun this calculation with a
new discharge.
4-6
QUICK-2 User's Guide Normal Depth Tutorial
SCREEN PROMPT -"Enter Slope and Press cEnter>"
2. Press cF2 >.
SCREEN PROMPT -"Enter Discharge and Press cEnter>"
3. Enter 500 and then Press <Enter>.
SCREEN PROMPT -"Enter Slope and Press <Enter>"
4. Press <Enter>.
After all of the data is input your screen should look like this:
NORMAL DEPTH -
TRAPEZOIDAL CHANNEL
INPUT VARIABLE ·S:
L Side Slope (H:V) 3.0:1 R Sid~ .. Slope (H:V) 2.0: 1
Bottom Width (ft) 10.0 Manning's n 0.0350
Discharge (cfs) 500 Depth. :(ft) 3.27
Slope (f t/ft) 0.0050
OUTPUT VARIABLES
Area (sq ft) 59.6 Wet Perimeter (ft) 27.7
Velocity (ft/s) 5.0 Hyd Radius 2.2
Top Wid t h (ft) 26.4 Froude # 0.6
Flow Type SlllCRITI CAL
Begin C.lculatiana ~ter>
<· Back Tab <F2> Main Menu <F7>
4-7
QUICK-2 User's Guide Normal Depth Tutorial
5. Press <Enter> to begin the calculation.
After a split second the screen should look like this:
NORMAL DEPTH
TRAPEZOIDAL CHANNEL
INPUT VARIABLES
L Side Slope (H:V) 3.0:1
Bottom Width (ft) 10.0
Discharge (cfs) 500
Slope (ft/ft) 0.0050
R Side Slope (H:V) 2.0:1
Manning's n 0.0350
Depth (ft) 4.22
OUTPUT VARIABLES
Area (sq ft)
Velocity Cft/s)
Top Width (ft)
Begin Calculations
Print
<· Back Tab
86.7
5.8
31.1
<Enter>
<FS>
<F2>
Wet Perimeter
Hyd Radius
Froude #
(ft) 32.8
2.6
0.6
SUBCRITICAL Flow Type
Main Menu <F7>
Let's return to the Main Menu ... Just Press the <F7> Function Key
Critical Depth
Channel Capacity
Normal Depth
Step-Backwater
QUIT
QUICK - 2
MAIN MENU
Press
1
2
3
4
<F10>
.., If you want to continue and to perform the Step-Backwater
Tutorial, then turn to the next page . .., .., .., ..,
.., If you want to exit out of the program for now, Press <FlO>. •
4-8
QUICK-2 User's Guide Step-Backwater Tutorial
STEP-BACKWATER {Tutorial Time: 20 to 25 minutes}
Let's say that we have a piece of property located in an unnumbered
Zone A, and we need to determine if our property is really in or out
of the floodplain. We will be referring to Figure 1 on the next page
which represents a plan view of our proposed floodplain study (step-
backwater analysis) . We have field surveyed 3 cross-sections to use
in the step-backwater analysis. The next page lists all of the data
from the field surveyed cross-sections.
If you have continued from the previous Normal Depth Tutorial you
should see the screen below. If you are just starting the program,
you will see the screen below after pressing Q2 and <Enter>.
Critical Depth
Channel Capacity
Norma l Depth
Step-Backwater
QUIT
QUICK - 2
MAIN MENU
Press
1
2
3
4
<F10>
1. Press 4 and then press <Enter> to start the Step-Backwater Option.
Next you will see the Starting Water Surface Elevation Method screen:
Starting Water Surface Elevation Method
NORMAL DEPTH (Slope-Area)
Enter the Slope in Ft/Ft
OR
KNOWN WATER SURFACE ELEVATION
Enter the known ws Elevation
Enter • Slope or an Elevation:
Input
(for ex. .0025)
(for ex. 656.78)
Let's say that we do not have any previous information about flood
elevations for our sample stream. Thus we need to start the step-
backwater analysis assuming that the flow in our first cross-section
is at Normal Depth. (This assumes that the channel slope downstream
of our first cross-section will approximate the slope of the energy
grade at the first cross-section of our study.) Let's assume that our
calculated downstream channel slope is .0029 ft/ft.
2. Type .0029 and then press <Enter>.
4-9
QUICK-2 User's Guide
CROSS SECTION INFORMATION
Cross-Section 1
GROUND POINTS
Station
362
4.25
509
512
602
605
732
1020
Elevation
505.0
499.1
498.0
496 .9
496 .9
498.2
500.1
504.7
CHANNE~ BANK STATIONS
Left 509 Ri ght 605
MANNING'S N VALUES
Left .065
Channel .040
Right .060
CHANNEL REACH LENGTHS
Left
Channel ---
Right ---
LOSS COEFFICIENTS
Cont ---Exp an
100-YEAR DISCHARGE
3000
FIGURE 1
515
Cross-Section 2
Station Elevation
0 510 .0
150 504.8
233 502.2
236 500.9
331 500.9
334 501.8
402 505.5
591 510.1
Left 233 Right 334
Left .055
Channel .040
Right .060
Left 450
Channel 450
Right 450
Cont 0 .1 Expan 0.3
1
3000
I
: PROPERTY
I
I
I
2
I
' I
' ' ' ~--······ ..... '
X SEC. 450
4-10
3
Step-Backwater Tutorial
Cross-Section 3
Station Elevation·
0 515.0
433 510.1
600 506.3
614 504.9
701 504 .8
725 506 .5
866 511.1
1240 514 .6
Left 600 Right 725
Left .065
Channel .040
Right .060
Left 490
Channel 490
Right 490
Cont 0 .1 Expan 0.3
3000
X SEC. 940
OUICK-2 User's Guide Step-Backwater Tutorial
The next screen you will see is the Input I Output screen as shown:
XSEC ID: 0 >> STEP -BACKWATER << GROUND POINTS
STAT ELEV STAT ELEV STAT ELEV STAT ELEV
CHANNEL BANK STATIONS: Left Right
MANNING'S N VALUES: Left Channel Right
CHANNEL REACH LENGTHS: Left Channel Right
LOSS COEFFICIENTS: Contractn Expansn :Dschrg
WS ELEV Depth Top Wid Kratio
EG ELEV Flow Regime ChanVel Froud#
F2><-Back Tab F5)List Files F6>Retrieve File F7>Main Menu F10>Ed/Ex GrPt
F3)1nsert GrPt F4)Delete GrPt F1 )HELP
Before we go on let's read about how data is to be input for this
screen.
3. Press <Fl> to access the Help screen.
4. When you are finished reading the Help screen just Press <Enter>.
If you refer to the previous page, you will see a tabulation of the
Ground Points for the first field surveyed cross-section listed by
Station and Elevation. You will also see the Channel Bank Stations,
Manning's N values, and Discharge.
S. Following the method explained in the Help Screen, enter the
Ground Points one at a time, by their respective Station and
Elevation. Be sure to Press <Enter> after you have typed in each
correct number.
Once you have entered all of the Ground Points correctly
6. Press <FlO> to Exit from entering Ground Point data
NOTE: The <FlO> Key will EXIT you from the top of the screen, or it
will RETURN you to the top of the screen if you need to go back to
EDIT the Ground Points.
4-11
QUICK-2 User 's Guide Step-Backwater Tutorial
Your screen should now look like this:
XSEC ID: 0 >> STEP -BACK\.IATER << GROUND POINTS
STAT ELEV STAT ELEV STAT ELEV STAT ELEV
362 505.0 425 499.1 509 498.0 512 496.9
602 496.9 605 498.2 732 500.1 1020 504.7
CHANNEL BANK STATIONS: Left Right
MANNING'S N VALUES: Left Channel Right
CHANNEL REACH LENGTHS: Left Channel Right
LOSS COEFFICIENTS: Contractn Expansn :Dschrg
WS ELEV Depth Top Wid Kratio
EG ELEV Flow Regime ChanVel Froud#
F2)<-Back Tab F5>PRINT f6}SAVE F7)Main Menu F8>New XSEC F10>Ed/Ex GrPt
Enter LEFT Channel 8-* Station and Press <Enter>
The program i s currently prompting you to enter the Left Channel Bank
Station. Using the information contained on the previous page, we
know that our Left Channel Bank Station is 509. Therefore ...
7. Enter 509 and then Press <Enter>. (Notice that the 509 has
been entered to the right of "CHANNEL BANK STATIONS: Left".)
Next you will see the Input I Output screen with a new prompt:
SCREEN PROMPT -"Enter RI GHT Channel Bank Station and Press <Enter>"
Using the information for Cross-section 1, simply follow the screen
prompts to input the required data, as follows:
SCREEN PROMPT -"Enter R I GHT Channel Bank Station and Press cEnter>"
8. Type 605 and then Press <Enter>.
SCREEN PROMPT -"Enter LEFT Manning's n Value and Press cEnter>"
9. Type .• 065 and then Press <Enter>.
SCREEN PROMPT -"Enter CHANNEL Manning's n Value and Press <Enter>"
10. Type .040 and then Press <Enter>.
SCREEN PROMPT -"Enter RIGHT Manning's n Value and Press <Enter>"
11. Type .060 and then Press <Enter>.
SCREEN PROMPT -"Enter Discharge and Press <Enter>"
12. Type 3000 and then Press <Enter>.
4-12
QUICK-2 User's Guide Step-Backwater Tutorial
Your screen should now look like this:
XSEC ID: 0 >> STEP -BACKWATER << GRCXJND POINTS
STAT ELEV STAT ELEV STAT ELEV STAT ELEV
362 505.0 425 499.1 509 498.0 512 496.9
602 496.9 605 498.2 732 500.1 1020 504.7
CHANNEL BANK STATIONS: Left 509.0 Right 605.0
MANNING'S N VALUES: Left 0.0650 Channel 0.0400 Right 0.0600
CHANNEL REACH LENGTHS: Left Channel Right
LOSS COEFFICIENTS: Contractn Expansn :Dschrg 3000
WS ELEV Depth Top Wid Kratio
EG ELEV Flow Regime ChanVel Froud#
F2><·.Back Tab F5>PRINT F6}SAVE F7lMain Menu F8>New XSEC F10>Ed/Ex GrPt
TO BEGlll CAlaJLATIOllS Press <Enter>
The program is now ready to begin the calculations since all of the
required data has been entered for the 1st cross-section of our step-
backwater analysis. Note that even at this point, if any of the data
on the screen has been typed in incorrectly, the user can simply
press the <F2> key to toggle backwards through all of the input data,
even back to the Ground Points. Remember that you can instantly go
back to the Ground Points by pressing <FlO>, also.
13. Press <Enter> to Begin the Calculations.
Your screen should now look like this:
XSEC ID: 0 >> STEP · BACKWATER << GRCXJND POINTS
STAT ELEV STAT ELEV STAT ELEV STAT ELEV
362 505.0 425 499.1 509 498.0 512 496.9
602 496.9 605 498.2 732 500.1 1020 504.7
CHANNEL BANK STATIONS: Left 509.0 Right 605.0
MANNING'S N VALUES: Left 0.0650 Channel 0.0400 Right 0.0600
CHANNEL REACH LENGTHS: Left Channel Right
LOSS COEFFICIENTS: Contractn Expanan :Dachrg 3000
WS ELEV 501.03 Depth 4.13 Top Wid 385 Kratio 1.00
EG ELEV 501.32 Flow Regime ,.., ChanVel 5.10 Froud# 0.50
F2><· Back Tab f5}PRINT f6}SAVE F7>Main Menu F8>New XSEC F10)Ed/Ex GrPt
As you can see from the screen, the (100-year) Water Surface
Elevation (WS ELEV) has been computed (501.03), with other variables.
4-13
QUICK-2 User's Guide Step-Backwater Tutorial
Before we move on to enter the data for the next cross-section let's
obtain a printout of this first calculation.
CJ Press <FS>.
The screen prompt will be ...
PRINT: Swmnary or Detailed? Press S or D and <Enter>
Let's obtain a Detailed Printout ... Therefore ...
CJ Press D and then Press <Enter>.
Assuming your printer is turned on, the detailed printout will look
like this:
.. Cross Section: 0 .. .. .. XLOB: 0 XLCH: 0 XROB: 0 CC: 0 CE: 0 .. .. .. .. .. .. NLOB: .065 STCHL: 509 NCHL: .04 STCHR: 605 NROB: .06 .. .. .. .. .. .. STAT ELEV STAT ELEV STAT ELEV STAT BLBV .. .. .. 362.00 505.00 425.00 499.10 509.00 498.00 512.00 496.90 .. .. .. 602.00 496.90 605.00 498.20 732.00 500.10 1020.00 504.70 .. .. .. .. .. .. CWSEL EG ELM IN QLOB QCH QROB .. .. .. Chan Vel HV KRATIO ALOB ACH AROB .. .. .. Depth HL Top Width STAT-L ST-MIDCH STAT-R .. .. .. Discharge OL Froude # CH-Slope EG-Slope FlowRegim .. .. .. 501.03 501.317 496.90 493 2003 505 .. .. .. 5.10 0.29 1.00 228 392 265 .. .. .. 4.13 0.00 385 404.4 557.0 789.9 .. .. .. 3000 0.00 0.50 0.0000 0.0029 .. ..
If any of the above variables are unfamiliar, a description of each
is provided in Appendix 1.
If you want to save the cross-section data to a different name and/or
directory, before pressing <F8>, you can Press <F6>, · (F6}SAVE) , to
perform this.
Now we need to enter the data for the 2nd cross-section. Since we are
entering a new cross-section (New XSEC), we need to ...
CJ Press <F8>.
Before the Screen changes you will notice that at the bottom of the
screen a message will briefly appear ...
SAVING TEMPORARY FILE C:\QUICK2\DATA\TO.XSC
This alerts you that your cross-section data has been saved to a file
called TO.XSC, which is located in your C:\QUICK2\DATA directory.
4-14
QUICK-2 User's Guide Step-Backwater Tutorial
Your screen should be blank again as shown below:
XSEC ID : 0 >> STEP -BACKWATER << GRCXJND POINTS
STAT ELEV STAT ELEV STAT ELEV STAT ELEV
CHANNEL BANK STATIONS: Left Right
MANNING'S N VALUES: Left Channel Right
CHANNEL REACH LENGTHS: Left Channel Right
LOSS COEFFICIENTS: Contractn Expansn :Dschrg
WS ELEV Depth Top Wid Kratio
EG ELEV Flow Regime ChanVel Froud#
F2}<-Back Tab F5}List Files F6}Retrieve File F7}Main Menu F10}Ed/Ex GrPt
F3}1nsert GrPt F4>Delete GrPt F1 }HELP
C Following the method used before, for the 1st cross-section, enter
the Ground Points one at a time, by their respective Station and
Elevation for the 2nd cross-section using the data provided. Be
sure to Press <Enter> after you have typed in each correct number.
C Once you have entered all of the Ground Points correctly, remember
to Press <FlO> to Exit from entering Ground Point data
C Follow the on screen prompts to enter all of the other data.
Remember that if any of the data on the screen has been typed in
incorrectly, the user can simply press the <F2> key to toggle
backwards through all of the input data, even back to the Ground
Points. (You can also Press <FlO> to go back to the Ground Points
immediately for editing) .
After entering all the data your screen should now look like this:
XSEC ID: 450 >> STEP -BACKWATER << GRCXJND POINTS
STAT ELEV STAT ELEV STAT ELEV STAT ELEV
0 510.0 150 504.8 233 502.2 236 500.9
331 500.9 334 501.8 402 505.5 591 510.1
CHANNEL BANK STATIONS: Left 233.0 Right 334.0
MANNING'S N VALUES: Left 0.0550 Chamel 0.0400 Right 0.0600
CHANNEL REACH LENGTHS: Left 450 Chamel 450 Right 450
LOSS COEFFICIENTS: Contractn 0.1 Expansn 0.3 :Dschrg 3000
WS ELEV Depth Top Wf d Kratf o
EG ELEV Flow Regime ChanVel Froud#
F2><-Back Tab F5}PRINT F6}SAVE F7}Main Menu F8}New XSEC F10>Ed/Ex GrPt
TO BEGIM CALQJLATJ<llS Presa <Enter>
4-15
QUICK~2 User's Guide Step-Backwater Tutorial
The program is now ready to begin the calculations since all of the
required data has been entered for the 2nd cross-section of our step-
backwater analysis.
ICJ Press <Enter> to Begin the Calculations.
Once the calculation is finished you may ...
ICJ Press <FS> to obtain a printout
ICJ Press <F6> to save the data to another name and/or directory
Finally, to finish our analysis we need to enter in the data for the
3rd cross-section.
ICJ Press <F8>
Before the Screen changes you will notice that at the bottom of the
screen a message will briefly appear ...
SAVING TEMPORARY FILE C:QUICK2\DATA\T450.XSC
This alerts you that your 2nd cross-section data has been saved to a
file called T450.XSC, which is located in your C:\QUICK2\DATA
directory. Notice that the 450, represents the channel distance
between the 1st and 2nd cross-sections.
C Following the method used before for the other cross-sections,
enter the Ground Points one at a time, by their respective Station
and Elevation for the 3rd cross-section using the data provided. Be
sure to Press <Enter> after you have typed in each correct number.
C Once you have entered all of the Ground Points correctly, remember
to Press <FlO> to Exit from entering Ground Point data
C Follow the on screen prompts to enter all of the other data.
After entering all the data for the 3rd cross-section
ICJ Press <Enter> to Begin the Calculations.
Once the calculation is finished you may ...
ICJ Press <PS> to obtain a printout
CJ Press <P6> to save the data to another name and/or directory
TO EXIT OUT OF THIS SCREEN NOW THAT OUR ANALYSIS IS COMPLETED ••.
ICJ Press <1'7>
4-16
QUICK-2 User's Guide Step -Backwater Tutorial
You will see a screen prompt at the bottom
SUMMARY PRINTOUT: Press <F5>, otherwise Press <Enter>
To print a summary of the output for all 3 cross-sections then ...
C Press <F5>, otherwise just Press <Enter>
The on screen Summary or the printed summary will look like this:
SECNO
0
450
940
Q
3000.0
3000.0
3000.0
XLCH
0
450
490
CWSEL
501.03
503.96
508.54
FR#
0.50
1.06
0.71
ELMIN
496.90
500.90
504.80
AVG.VEL.
3.39
7.54
4.95
ARE A
885.0
398 .1
606 .5
TOPWID
385.5
196.9
286.2
If we carefully compare the Computed Water Surface Elevations
(CWSELs) at each cross-section, to the topographic contours on
Figure 1, we will see that the property is clearly higher than
the CWSEL at evezy cross-section. Therefore this analysis with
more detailed cross-section data has proven that the property
has been inadvertently included in an unnumbered Zone A Special
Flood Hazard Area.
Turn to the next page to continue ================ ............
4-17
QUICK-2 User's Guide Step-Backwater Tutorial
RUNNING HEC-2 USING QUICK-2 FILES {Tutorial Time: s minutes}
C You will be prompted one more time to Press <Enter>. The next
prompt will ask you a question concerning running the HEC-2 or
PLOT-2 programs.
Press Y and <Enter> to rerun w/HEC-2 or PLOT-2: If NO Press <Enter>
C For purposes of this tutorial let's answer "Y'' , (and Press
<Enter>) to run the HEC-2 program. The next screen that will appear
will include the following:
To Run
QUICK-2
HEC-2
AUTOHEC-2
PLOT-2
VIEW/PRINT
C Type AH2 and Press <Enter>.
Type
Q2
H2
AH2
P2
LIST
Once the HEC-2 run is complete it will return you to the above-
mentioned screen.
NOTE: Typing AH2 runs the HEC-2 program automatically using the
QUICK-2 generated HEC2.DAT, HEC-2 data file.
If you are using a HEC-2 data file other than HEC2.DAT, then Type
H2 and Press <Enter>. Follow the directions on the screen for
naming the Input, Output and Tape95 files; pressing <Enter> after
each filename is typed in.
C Type LIST and Press <Enter>, and then enter your output
filename, (Default is HEC2.0UT), to view the results . Note
that you move up, down and across the screen using the <Page UP>,
<Page Down>, the cursor keys, etc.
C To Print the data that appears on the screen simply Press P.
C To Exit from the screen simply Press X or the Escape key.
If you would like to complete the next tutorial example, then
Type Q2 and Press <Enter>; and, turn to the next page. ... .........
4-18
QUICK-2 User's Guide Step-Backwater Tutorial
RERUNNING USING SAVED CROSS-SECTION FILES
{Tutorial Time: 5 minutes}
Let's say that in the analysis that was performed in the previous
tutorial, we want to change the discharge from 3000 to 5000, and run
the step-backwater option again with the same cross-sections. This is
quite easily done. Just follow the steps as shown below.
1. At the Main Menu Screen Type 4 and Press <Enter>
2. At the Starting Water Surf ace Elevation Method Screen
Type .0029 and Press <Enter>
3. At the Input/Output Screen Press <F6> to retrieve a saved cross-
sect i on file
Assum i ng your 1st cross -section file is stored as
C :\QUICK2\DATA\TO.XSC
Type C and Press <Enter> when prompted for the d i rectory
Type QUICK2\DATA & Press <Enter> when prompted for the subdirectory
Type TO and Press <Enter> when prompted for the filename
4. Press <F2> to toggle back to the "Enter Discharge" prompt
5. Type 5000 and Press <Enter> to enter the new discharge
6. Press <Enter> to Begin the Calculations
7. Press <F8> to input another cross-section
Press <F6> to retrieve a saved cross -section file
Assuming your 2nd cross-section file is stored as
C :\QUICK2\DATA\T450.XSC
Type C and Press <Enter> when prompted for the directory
Type QUICK2\DATA & Press <Enter> when prompted for the subdirectory
Type T450 and Press <Enter> when prompted for the filename
8. Press <F2> to toggle back to the "Enter Discharge" prompt
9. Type 5000 and Press <Enter> to enter the new discharge
10. Press <Enter> to Begin the Calculations
4-19
OUICK-2 User's Guide Step-Backwater Tutorial
11. Press <F8> to input another cross-section
Preas <F6> to retrieve a saved cross-section file
Assuming your 3rd cross -section file is stored as
C:\QUICK2\DATA\T940.XSC
Type C and Press <Enter>
Type QUICK2\DATA & Press <Enter>
Type T940 and Press <Enter>
when prompted for the directory
when prompted for the subdirectory
when prompted for the filename
12. Press <F2> to toggle back to the "Enter Discharge" prompt
13. Type 5000 and Press <Enter> to enter the new discharge
14. Press <Enter> to Begin the Calculations
CJ Press <F7> to Ex i t out of the screen
CJ Press <FS> to obtain a summary printout
CJ Press <Enter> tw i ce to get back to the main menu
CJ Press <FlO> to leave the program
Q.E.D.
4-20
QUICK-2 User's Guide Channel Capacity Tutorial
CHANNEL CAPACITY OPTION WITH THE RATING CURVE PLOT
{Tutorial Time: 5 to 10 minutes}
Let's say that we need to determine a Base Flood Elevation (BFE) for
the property shown in Figure 1. We do not want to exempt the entire
property from the flood plain, only a structure which is located in
the middle of the property. Therefore, we can use one cross-section
(the 2nd cross-section (T450.XSC) from our previous tutorial and
shown on Figure 1), to compute a BFE.
Let's assume that we know the discharge is between 3000 cfs and 4000
cfs based on our best estimates.
Let's assume our structure does not have a basement; the lowest
adjacent grade (LAG) to the house is at elevation 510 NGVD; and the
first floor elevation (FFE) is 510.5 NGVD.
Let's determine the maximum carrying capacity of the floodplain using
a depth equal to the lowest adjacent grade (510.0) minus the minimum
stream elevation (500.9). For purposes of this example we'll use a
depth of 9 feet (510-501) .
To perform a channel capacity calculation we also need ~o know the
downstream slope, which in this case is easy to compute from the
information on page 4-10. Slope = 500.9 -496.9 I 450 = .0089.
The graphic below sums up our situation so far:
I_, = 510.5
\ \/ WSE = ?
Stream Invert = 500.9
Follow the steps as shown on the next page to conq:mte the rating
curve . . . ..,. ..,. ..,. ..,.
4-21
QUICK-2 User 's Guide Channel Capacity Tutorial
1. At the Main Menu Screen Type 2 and Press <Enter>
2. At the Shape of Cross Section Screen
Type I and Press <Enter>
3. At the Input/Output Screen Press <F6>
We are usi n g the 2nd cross-section file stored as
C:\QUICK2\DATA\T450.XSC
Type C and Press <Enter> when prompted for the directory
Type QUICK2\DATA & Press <Enter> when prompted for the subdirectory
Type T450 and Press <Enter> when prompted for the filename
4. Type .0089 and Press <Enter> to enter the slope
5. Type 9 and Press <Enter> to enter the depth
6. Press <Enter> to Begin the Calculations
7. Press <F4> to Plot to screen .... Press <F5> to Print
Looking at the rating curve plot we can see that for a discharge
range of between 3000cfs -4000cfs the BFE ranges from about 504.3 to
504.8. Since our lowest adjacent grade and first floor elevation are
at or above 510, it is clear that this structure is above the BFE.
M-FFE
% +----LAG = 510.0
= 510.5
WSE = 504.3-504.8 t
I
9.1'
I
\ ~ Stream Invert = 500.9
Slope = .0089
8. Press <Enter> to continue
9. Press <F7> t o go back to the Main Menu
10. Press <FlO> to Exit the program
4-22
QUICK-2 User's Guide PLOT-2 Tutorial
PLOT-2
In general PLOT-2 will only work on QUICK-2 files that have been converted into
HBC-2 format using QUICK-2's Step-Backwater option.
Profile plots from PLOT-2 will work only if the QUICK-2 generated data file
(HBC2.DAT) is also run using the HEC-2 program (see Running HEC-2 Using QUICK-2
Files, page 4-18), since a HEC2.T95 file needs to be generated by the HEC-2
program for use by PLOT-2.
PLOT-2 Cross-section plots can be generated using the QUICK-2 generated data file
(HBC2.DAT) even if it is not run with HEC-2. However, the Cross-section plot will
not show the computed water surface elevation (CWSEL) unless the QUICK-2 HEC2.DAT
file is run with HEC-2, since the CWSEL is found on the HEC2 .T95 file.
Note that the user can compute a normal depth elevation for only one cross-section
and have that cross-section plotted by choosing the Step-Backwater option and the
Normal Depth starting water surface elevation method. Once the computation is
finished, the user simply exits (Presses <F7>) , and the QUICK-2 program
automatically creates the HEC2.DAT file for that one cross-section, which can be
used by the PLOT-2 program.
Let's say that we want to view the water surface elevation profile
and the cross..:.section plots from our previous tutorial on the Step-
Backwater option.
C From the QUICK-2 Title screen Press P2
C You are now into the PLOT-2 program, Press <Enter> to continue
PROFILE PLOT {Tutorial Time: 5 to 10 minutes}
1. Let's view the profile first. Press 1 from the PLOT-2 main menu
selection
2. Cursor to the HEC2 Tape95 file name entry and Type ?
This will list all of the data files in the QUICK-2 directory.
T95 files are designated with the 3 letter extension .T95 .
Therefore cursor over to highlight that file (HEC2.T95) and Press
<Enter>.
3. Move up to highlight the Plot profiles entry and Press <Enter>.
4. Your profile is now plotted. Pressing <Enter> moves you back to
the Pr~file plots main menu screen. You can explore the different
Profile and Plotting options and replot the profile if you wish.
5. When you are finished plotting, highlight the Return to main menu
message and Press <Enter>
4-23
QUICK-2 User's Guide PLOT-2 Tutorial
CROSS-SECTION PLOT {Tutorial Time: s to 10 minutes}
1. From the PLOT-2 main menu Press 2 from the menu selection.
2. Cursor down to the HEC2 input file name entry and Type ?
This will list all of the data files in the QUICK-2 directory.
Input files are designated with the 3 letter extension .DAT .
Therefore cursor over to highlight that file (HEC2.DAT) and Press
<Enter>. If we want to view a different data file than that of the
profile we previously viewed, we would have to specify a different
file here before proceeding.
3. Cursor down to the HEC2 Tape95 file name entry
Note that we do not have to re-enter this file since we have
already entered it previously. If we want to view a different
Tape95 file than that of the profile we previously viewed, we
would have to Type ?, and then specify a different file here
before proceeding.
4. Move up to highlight the Plot cross sections entry and Press
<Enter>.
5. You now have the option of printing all or selected cross sections
from your data file. Press Y for plotting all, or N for plotting
selected cross sections.
Your first cross-section is now plotted. Pressing <Enter> moves
you back to the Cross-section plots main menu screen or plots
additional cross-sections depending on how many cross-section
plots you have. You can explore the different Cross-section and
Plotting options if you wish.
6. Highlight the Return to main menu message and Press <Enter>
Pressing 4 at the PLOT-2 main menu exits you from PLOT-2 and back
to the QUICK-2 title screen.
Note: To use PLOT-2 and to access data files that are in another
directory (i.e., they are not in the C:\QUICK2 directory), just
change to that data directory (i.e., CD\dirname) and access PLOT-2 by
typing C: \QUICK2\PLOT2 (or A: \PLOT2 if using the program from the
floppy drive) from that data directory.
4-24
Chapter 5: FORMULAS
Critical Depth
Channel Capacity
Normal Depth
Step-Backwater
5-1
QUICK-2 User's Guide Critical Depth Formulas
1. CRITICAL DEPTH
In every cross-section for a given discharge there exists a critical depth, where the
energy grade (depth of water plus velocity head -V2/2G) is at a minimum. Increasing
the discharge above this given discharge will force the flow into the super-critical
regime. Discharges below the given discharge will remain in the sub-critical regime.
Super -critical depths will be lower than the critical depth, and sub-critical depths
will be above the critical depth. Super-critical flow is characterized by small water
depths with large velocity heads; while, sub-critical flow is characterized by large
water depths with small velocity heads. A rule of thumb used to determine critical
depth is that when the Velocity Head equals 1/2 the hydraulic depth (Area/Topwidth)
critical flow is probable. ·
A formula which can be used to approximate critical depth (De) is
given below.
Qc2 I g • A3 I T
Where .Qc is the discharge (in cfs) based on critical depth, g is the gravitational
constant (32.15 feet/second squared), A is the cross-section area (in square feet),
and T is the top width of the water surface (in feet). Note: for rectangular channels
the above equation can be reduced so that De = (Qc/5. 67 T) .M7 •
The more exact way to compute critical depth (minimum specific energy) is to find a
specific depth of water within a cross-section for a given discharge which produces
the lowest energy grade. The following represents the process that the Critical Depth
option of QUICK-2 goes through to calculate critical depth.
After the cross-section information (ground points, channel stations, etc.) has been
input the program starts computing the water surface elevation (WSE) and corresponding
energy grade elevation (EG) at a depth of 0.1 foot above the lowest elevation in the
cross-section. It continues to calculate WSE and EG at intervals of 0.5 foot. As the
depth of water in the cross-section increases the EG will decrease. At one point the
EG will begin to increase. This means that between the last 0.5 foot interval there
exists a minimum energy grade. Once this has occurred the program decreases the WSE
in intervals of .02 foot. As the depth of water decreases in the cross-section the
EG will also decrease as it approaches the minimum specific energy. At one point the
EG will begin to increase again.
This means that between the last .02 foot interval critical depth exists . At this
point the screen will display the actual critical water surface elevation (along with
other variables) by assuming that the next to the last iteration was the critical
depth.
The calculations performed by the program for a given cross-section are listed on the
next page . The calculations include the iterations that the program goes through to
arrive at critical depth.
5-2
QUICK-2 User's Guide Critical Depth Fonnulas
ELMIN • 92.5
WSE • 92 .. 6 QC• 6.026845E-02 Q• 260 EG•466080.8 EG Decreasing
WSE• 93.1 Qc= 5.314738 O= 260 EG=452.6406
WSE• 93.6 QC= 24 .18726 Q= 260 EG:sl25.4259
WSE• 94.1 QC= 61.71717 Q= 260 EG=lOl.21
WSE= 94.6 Qc= 121.451 Q= 260 EG=96.99928
WSE= 95.1 Qc= 204.4488 Q= 260 EG=96.14474 v
WSE= 95.6 Qc= 311.15 Q= 260 EG=96.14897 + EG Increasing
Therefore Mini mum Specific Energy is between WSE's of 95.1 and 95.6.
Note also that the Discharge {Q = 260) is also within the computed
Critical Discharge {Qc) range of 204 -311.
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSE=
WSB=
WSE=
95.58
95.56
95.54
95.52
95.50
95.48
95.46
95.44
95.42
95.40
95.38
95.36
95.34
95.32
95.30
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
QC=
306.5006
301.8821
297.2962
292.7447
288.2256
283.737
279.2825
274.8583
270.4678
266.1075
261.7806
257.4854
253.22
248.986
244.76
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
Q=
260
260
260
260
260
260
260
260
260
260
260
260
260
260
260
EG=96.14179
EG=96.13499
EG=96.12863
EG=96.12271
EG=96.11724
EG=96.11225
EG=96.10776
EG=96.1038
EG=96.10038
EG=96.09752
EG=96.09525
EG=96.09361
EG=96.09262
BG=96.09199
EG=96.09271
-EG Decreasing
I
I
I
I
v
I
I
I
minimum v
+ EG Increasing
We assume that •.• Critical Depth= 95.32', Minimum Specific Energy= 96.09199'
The Froude number would be, Q I Qc, or 260 I 248.986 = 1.04.
It is not unusual for the Froude number to not e'.flal exactly 1. O, since the
calculation of critical discharge using the formula Qc I g = A3 I T, does not always
yield a WSE that is exactly at the True minimum specific energy.
You should notice from the above tabulation, that as you approach critical depth
{minimum specific energy) , for very small changes in EG there are large jumps in the
water surface elevation. The EG is only changing by .001' to .003' while the WSE
changes by .02'. A 0.01' difference in EG can cause a 0.10' change in WSE.
5-3
QUICK-2 User's Guide Channel Capacity Formulas
2. CHANNEL CAPACITY
In this option, a Normal Depth elevation (see 3. NORMAL DEPTH) is input and the
program computes the corresponding discharge. (In the Normal Depth option, the
discharge is input and the program computes a normal depth elevation). The Manning's
equation is used as the formula for determining the (normal) discharge.
Q • 1.486 A (R'667 ) 9.5 I N
Where Q is the discharge (in cfs), A is the cross-section area (in square feet), R
is the hydraulic radius (in feet), S is the energy slope (in feet/feet), and N is the
Manning's roughness value.
After the cross-section information (ground points, channel stations, streambed slope,
normal depth elevation(s)., etc.) has been input, the program simply solves for the
area (A) and hydraulic radius (R) below the normal depth elevation (specified by the
user) and computes the (normal) discharge directly using the Manning's equation. This
is not an iterative process. The screen will display the (normal) discharge (which
represents the channel capacity) along with other variables.
5-4
QUICK-2 User's Guide Normal Depth Formulas
3. NORMAL DEPTH
The standard formula for determining normal depth in a cross-section is the Manning's
formula. Water is flowing at normal depth when the energy grade and the hydraulic
grade (water surface) slopes are the same as the stream bed slope . Normal depth
profiles occur, in general, when the flow is uniform, steady, one-dimensional, and
is not affected by downstream obstructions or flow changes. The standard Manning's
equation is:
Q • 1. 486 A (R·667 ) s-' /N
Where Q is the discharge (in cfs), A is the cross-section area (in square feet), R
is the hydraulic radius (in feet), Sis the energy slope (in feet/feet), and N is the
Manning's roughness value.
The exact method for computing normal depth for a given discharge at a particular
cross-section, is to assume that S is equal to the downstream streambed slope and to
solve iteratively for the depth (this obviously assumes N is known) . The following
represents the process that the Normal Depth option of QUICK-2 goes through to
calculate normal depth.
After the cross-section information (ground points, channel stations, discharge,
streambed slope, etc.) has been input, the program starts computing discharge using
the Manning's equation at an initial depth of 0.1 foot above the lowest point in the
cross-section, and from that point in 0.5 foot intervals . At some point, the computed
discha_rge will exceed the given target discharge . The program then uses a converging
technique to compute a discharge (with a corresponding normal depth) that is within
1\ of the given discharge. At this point the screen will display the actual normal
depth water surface elevation (along with other variables) .
The calculations performed by the program for a given cross-section are listed below.
The calculations include the iterations that the program goes through to arrive at
normal depth.
ELM IN= 92.5
WSE 92.6 Q= 260 Computed Q= .023579 below target Q
WSE= 93.1 Q= 260 Computed Q= 2.803083 below
WSE= 93.6 Q= 260 Computed Q= 14.11313 below
WSE= 94 .1 Q= 260 Computed Q= 38.33264 below
WSE= 94.6 Q= 260 Computed Q= 80.01045 below
WSE= 95.1 Q= 260 Computed Q= 146.9773 below
WSE= 95 .6 Q= 260 Computed Q= 245.9516 below
WSE= 96 .1 Q= 260 Computed Q= 369 .2461 above target Q
WSE= 95 .65697 Q= 260 Computed Q= 258.7531 within H
We assume that ••• Normal depth• 95.66 for a Discharge (Q) of 260 cfs
5-5
OUICK-2 User's Guide Step-Backwater Formulas
4. STEP-BACKWATER
The Bnergy Bquation which represents one-dimensional, uniform, and steady flow in open
channels is shown below.
(1) WSBd + HVd • WSB,. + HV,. + HL + OL
Where WSEd is the water surface elevation at the downstream cross-section, HVd is the
velocity head at the downstream cross-section, WSE 11 is the water surface elevation
at the upstream cross-section, HV11 is the velocity head at the upstream cross-section,
HL is the friction loss between the two cross-sections, and OL is the eddy
(contraction or expansion) loss between the two cross -sections.
Velocity Head, HV, is calculated as follows:
HV • (a) v2 I 2g
Where (a) is alpha the velocity coefficient, V is velocity (Q/A), and g is the
gravitational constant . Alpha (a) is calculated as follows:
11n 3 ltc3 ltr3
(a) .. 1---+ ---+
IA1 2 Ac 2 Ar2
Where A and Kare the total area and conveyance below the water surface, respectively;
and Kl, Kc, Kr and Al, Ac, Ar, are the conveyance and area in the left overbank ,
channel, and right overbank, respectively.
Friction Losa, HL, is calculated as follows:
HL • Lw ( Qd + Ou ) 2 / ( ltd + K,, ) 2
Where Lw is the discharge weighted reach length between cross-sections, Qd is the
discharge at the downstream cross-section, Q11 is the discharge at the upstream cross
section, ~ is the conveyance at the downstream cross-section, and K,. is the
conveyance at the upstream cross-section . This is derived from the Average Conveyance
Friction slope equation.
The Discharge Weighted Reach Length, Lw, is calculated as follows :
Lw • {(Ll * Ql) + (Le * Qc) + (Lr* Qr)} I Qa
Where Qa is the average total discharge between cross-sections; and, Ll, Le, Lr, and
Ql, Qc, Qr, represent the reach length and average discharge between cross -sections
for the left overbank, channel, and right overbank, respectively.
Bddy Losa, OL, is calculated as follows:
OL • (Ce or Cc) * ABS I HVd HV .. I
Where Ce is the expansion coefficient, Cc is the contraction coefficient, HVd
velocity head at the downstream cross-section, and HV11 is the velocity head
upstream cross-section . When HV11 is greater than HVd Ce is utilized. When
greater than or equal to HVd Cc is utilized.
5-6
is the
at the
HV 11 is
QUICK-2 User's Guide Step-Backwater Formulas
After the cross-section information for the first cross-section has been input, either
a known water surface elevation is input to start the calculations or the water
surface elevation could have been determined by the Normal or Critical Depth options
or by another source or method. The program then computes all pertinent variables for
the first cross-section that will be needed for an energy balance with the next
upstream cross-section. After this the user must put in the appropriate information
for the next cross -section (i.e , ground points, channel stations, reach lengths,
contraction and expansion coefficients, etc.). Once this is done the program performs
a series of trial iterations to make sure that the Energy Equation (l) listed
previously will balance to within .014 foot. The sequence of trial elevations is
listed below.
lST TRIAL:
Uses the depth of water (DP) of the previous cross-section added to the lowest
elevation (ELMIN) within the current cross-section. If DP + ELMIN is less than the
previous WSE (i.e., adverse slope condition) then the program uses the previous WSE
for the lst trial at the current cross-section.
2ND TRIAL:
Uses the average of the computed WSE and the WSE assumed in Trial number l.
3RD TRIAL AND ON . . . . .
Uses a formula designed to help converge quickly to balance the energy equation as
shown below:
Trial WSB • WSB-(WSB+HV-DG-HL-OL)/(1-((Q/QC)2 )+((1.S*HL)/(A/W)))
Where WSE, HV, HL, OL, QC, A, and W are the latest computations of water surface
elevation, velocity head, friction loss , eddy loss, critical discharge, total area ,
and total wetted perimeter, respectively; and, DG is the computed energy grade
elevation from the previous cross-section; and, Q is the discharge at the current
cross-section.
For most energy balances between cross-sections that are not at or near critical flow,
the program will balance the energy equation within 5 trials .
The calculations performed by the program for an energy balance between two
cross-sections are listed below. The calculations include the iterations that the
program goes through to arrive at the energy balance .
WSE
Assumed
98.75
98.53744
98 .32476
WSE
Calculated
98.32489
98.32472
98.32513
Difference
+.4251099
+.2127228
-.00037
We assume that the correct WSB • 98.32
Trial #
1
2
3
Note: Energy balance in this case was accurate to .00037 foot.
5-7
QUICK-2 User's Guide Definition of Variables
Appendix 1: Definition of Variables
ACH Area within the specified channel below the water surface elevation
ALOB Area within the specified left overbank below the water surface elevation
AROB Area within the specified right overbank below the water surface elevation
ALPHA -Velocity head coefficient
ARBA or Area -Total area within the cross-section below the water surface elevation
AVG.VBL or Velocity -Average Velocity within the entire cross-section
Base Width -Channel bottom width of a trapezoidal or rectangular cross-section
Bottom Width -Channel bottom width of a trapezoidal or rectangular cross-section
CC -Contraction Coefficient
CB -Expansion Coefficient
CH-SLOPB -Slope of the streambed, Channel Slope
CHAN-VBL or ChanVel -Velocity within the main channel of cross-section
Critical Slope -Slope of the Energy Grade line at Critical Flow
CWSBL -Computed water surface elevation within a cross-section
Depth -Maximum depth of water in the cross-section as measured below the water
surface elevation
Diameter -Width or Height of a circular pipe
Di•charge -The rate of the flow of a volume of water within a cross-section, usually
expressed in cubic feet per second (cfs)
BG or BG BLBV -Energy grade elevation, expressed as, WSE + HV
BG-Slope -Energy grade slope
BLBV -Elevation of a ground point of a cross-section, as referenced to some datum
(i.e., NGVD, NAVD, etc.)
BLMIN -Lowest elevation in a cross section
Flow Regime -Type of water surface profile (Supercritical regimes are not computed)
111: EG-Slope <• Ch-Slope and FR# < .8
112: EG-Slope > Ch-Slope and FR# < .8
Cl: EG:-Slope <= Ch-Slope and FR# >= .8
C3: EG-Slope > Ch-Slope and FR# >:a .8
rlow Type -either, Supercritical, Critical or Subcritical
rroude#, rroude No., rroud# or rR# -Froude number, used to determine the flow type
(i.e., •ub-(FR#< l), critical (FR#• l) or •uper-critical (FR#> l) flow)
HL -Friction loss between cross sections
KV -Velocity head
Ryd Radiu• or Ryd R -Hydraulic Radius: equal to (Area I Wet Perimeter)
A-1
QUICK-2 User's Guide Definition of Variables
KRATIO -Ratio of upstream total conveyance to downstream total conveyance
L Sid• Slope -Ratio of the slope of the left side of a channel in terms of Horizontal
distance in feet to 1 foot Vertical.
Manning' a n -Coefficient used to account for the friction caused by earthen,
vegetative, and/or man-made surfaces within a floodplain cross-section.
Max Discharge -The maximum flow possible within a circular pipe, (usually occurring
at .94 * Diameter).
NCHL -Manning's "N" value for the specified channel
NLOB -Manning's "N" value for the specified left over bank
NROB -Manning's "N" value for the specified right over bank
OL -Expansion/contraction loss
Q -Total discharge in the cross-section
QC -Critical discharge within the entire cross-section for a specific water surface
elevation
QCH -Discharge within the specified channel of a cross-section
QIC -Critical discharge within the entire cross-section for a specific water surface
elevation, assuming that critical flow is limited to the channel, even if flow is
occurring in the overbanks
QLOB -Discharge within the specified left overbank of a cross-section
QROB -Discharge within the specified right overbank of a cross-section
R Side Slope -Ratio of the slope of the right side of a channel in terms of
Horizontal distance in feet to 1 foot Vertical.
SECNO -Cross section number or identifier
Slope or BG-Slope -Energy grade slope
STAT-L -Station, within a cross-section, of the left edge of the water surface
STAT-R -Station, within a cross-section, of the right edge of the water surface
STAT -Station of a ground point of a cross-section
STCHL -Station of the left bank of a cross-section
STCHR -Station of the right bank of a cross-sectipn
ST-MIDCH -Station which represents the mid-point between the channel bank stations
Top Width or Top Wid -Top width of the water surface within a cross-section
Velocity -Average Velocity within the entire cross-section
Wet Perimeter or Wet Per -actual width of ground within a cross-section below the
water surface elevation.
ws BLBV or CWSBL -Water surface elevation within a cross-section
XLCH -Distance between cross-sections as measured along the channel
XLOB -Distance between cross-sections as measured along the left overbank
XROB -Distance between cross-sections as measured along the right overbank
A-2
Appendix 7
Hydraulic Coaputer Manuals
BEC-2
U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC), "Water Surface
Profiles, HEC-2, User's Manual," Davis, California, 1991.
BEC-RAS
U.S . Army Corps of Engineers, Hydraulic Engineering Center (HEC), "HEC-RAS, River
Analysis System, User's Manual -Draft," BETA 2 Test Version, Davis, California,
February 1995.
PSUPRO
Federal Emergency Management Agency, "PSUPRO Encroachment Analysis User's
Manual", Washington, D.C., 1989.
SFD
Federal Emergency Management Agency, "Simplified Floodway Determination Computer
Program User's Manual", Washington, D.C., 1989.
WSPRO
U.S. Geological Survey, "Water Surface PROfiles, WSPRO, User's Manual, Reston,
Virginia, 1990.
WSP2
U.S. Department of Agriculture, Natural Resources Conservation Service, "WSP2
Computer Program User's Manual", Technical Release No. 61, Washington, D.C.,
1976.
A7-l
Appendix 8
Normal Depth Hand Calculation
A8-l
Appendix a -continued
Normal Depth Hand Calculation
AS-2
App•ndix 8 -continued
Normal Depth Band Calculation
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tll c... tl :r 0 Ill
0 , 15 65 .. tr ..
0 " .. 2 .. .. uo / 3 I 17 IS~S 0 0 0 0 0 0 0 0
2 ?
II 0 0 2. 3!:> 3514 ?
"' 132 II 8 "' 4442 IN
/ 0 ...
STEP1 / r (P&. 35)
..... ...-
'2~Z 3 ~.s 0.3 32 .3.3 s 1-9 4z 0 0 4Z 2784 zz8 / 32.
'2..'-"" 6.S.381 .53.Sf 3Z 4.3 2. 6..5 2..9, 24 z 8.S 8841 724 SS 2 I
t<• hU.' AR.213 • I< .s'lz. . S' =:
11z. Q:: d·0067; .r :-o.o.f/4S ) I ' ~ n I ~ ' '-i 'STEP 7 (P6, 35) I ' _,..
•
Appendix 9 -continued
Weir Flow Hand Calculations
A9-2
Appendix 9 -continued
Weir Flow Band Calculations
Calculation Sheet
----------Date -------Checker ----------Date-------
Title ---------------------------------Job No.-------
Subject Sheet No. I of ....,$....___
~;~en : Q :: C,ooo cf .
Cl,c,-n n .e l !xdforn ..slof'e = O· CJ0067
7ne Cr(lJJ sech fi?? Jr./ lhe w~il' p~aj-1'/e /.J ..rhovvn on ~e 3 .
.So~tio-n:
~rn/7vde th e clov..n?..r k efA l'YI (/..)t:.ier -.J"u1';!t:<<e e lt-v~h(/YJ (WSEL) !y no;r-n~l de;:'#, rne/fi()/.
'1'1 e Ccny1.A.f e d dowrultt1?01 W.JEL.=-263.2;) fee t-.
/Jssw-ne tAf Sh <urn ~l?f 'S.Y 9,,0 c/c-' elevc.hr:fYI M ?d' wr>-1/0 /e !Ire wu·r Jlow.
4.r.rL<n?e .-a.r !earl:. lli ree vtl.Urc'J .
1•5
Q;.: @CLL./-IL. j C ="Z.'b I Q :::l:,Qt•
FirJt' ~f.ArY>e ,J ener:g::; grv.c/e e/e vAh o">-1 -. 2t:~·50 /Let-.
/
l·S 1·5
µ-~~nt-Sfol-iOY! f/ev6'h"'1 H Le H. H LL.H( Roc.J £L. t) 1>/H. ~ Q{ l-L" •
I 1000 Z 68 l·S 40 '2.t~ 3·~5 IS '6· o -Z.67 2·2' 0•91, "•30 370
10 4o z6G .3·5
z. 10 10 z. 6~ 3•5 80 5·0 I/· Ii &'~4·4 26.f·S 4·7::> "·95'8 0·73 ,,.:is
/I 20 Z.63 6·5
3 II 2-0 'Z (.3> 6·5 ~o 6·5 16·57 3.34· 2. H3 6·Z'J O·:J6 8 O• "4 I~ 5'4
II fo z63 ~·5
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,, 70 t,.:J,s O·
Se~J Ctife;.rned f.Af?J frecvYJ ene (Y!:) grc.de elevahm = 'Z 70· 0 fr .
~Mt'1t .S+-o«hO>, H L -He
l·S 1-5 Roo.J El, D D/H,: o. E'lev&o.~ L Hl. LC:H L . @
L
I 1000 268 2·o 40 3·0 S-20 20,. ~7· Z·23 0·7'3 o-9,s S33
/040 -Z.6' 4 ·0
z /04o ?-6(, "I·() 'i 0 5.5 IZ •-'O /o3Z· '2.'~·.S 4·73 O·O I (). !)7 Z.'03
1120 2.6.> 7·0
3 /120 z,3 7•0 60 7·0 18•52 //l/·2 263. ~.z,~ O·'t>~ t>·.93 2,.87
1180 7-'3 7,0
4 If 8(> 2.'J 7.0 9~ 3.·S r,.55 '4f·S Z'6·5 2·~!1 0·731 f>•.9:J I~ '!J
/279 7. 70 O·
Q
4874
Q
7492
Appendix 9 -continued
Weir Flow Band Calculation•
Calculation Sheet
Designer ----------Date -------Checker ----------Date-------
Title ---------------------------------Job No.-------
Subject Sheet No. _2. __ of _,3..__
t
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1
~
~
{
~
t\
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1·5 Q~ = @c Le: H,_. ; c-= z." ; Q,,, I..O.:
-th ird A.f.!1A.rnt?d vyurre~i?'? enery.!;19r.::..sle el~ve:..h't:n'I: '2~.9·7
H L· H..: 1•5 l•S
'Roo.JEl.. .se_, ..... @ .. 1 ,S'h;. IT(r,., Eltv'e.li.r> Hi: L· H . .D D/~. ~ Q. Q " L • •
'
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1040 '"'' 3•7
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3 ti 20 '2.C.3 ~·7
60 6·7 17.34 1040. 4 ,,~. t:-z:;; ()•.93~ O•lr'25 ZZ.32
11 iO 2t;;3 6·7
4 /llO 'Z6'3 ,.7 ~4 J·.35 ,.,J, 57r,. z '2.~6·3~ Z.·-'1 0•$78 0·.9(;. 14 38
tz.74 Z6.3·7 0 62!'4
z70.o
7. '~·6'6
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'ooo 70oo toao
in c/..1~
~ c;., olt'.tcAc..'Je c:J G tJOCJ c/.J U,P..!'IYt!V<m enf''3JI ;;rlY!e elevt:(.h~ = ~6.!J. ~~ jt-.
F~ CY'Prox;rnt~fe c;l'?~Ji..J WSel-¥.r~Arn: Ee, "'f.Jh..,.~:.rn = 2.~~-~~ Jf·
111-1
t:.rtJss sec hrn JIA )f~hm £/NP-htrn Sfr:i.hff>1 E /eve. h<rn >fc..H<rn £/ev~Hon en >i ti & E : (ii• ID cQ. ~ I ~ .. /0 O(J 2. 68 "() ()0 l68 I 13 2 '2-55 I 252 264 1040 7..6, / o4 O 2 6{, / 16 0 2.55 I 2~ I 2 66 II 20 Z '3 I 06 o 264 /I 7 5 260 1270 z.~g 1110 2 ,.3 I tJ 8 0 2...6'2. /23.4 z 60 / 273 270 12 1.s I z 10 I I I 5 7. ,6 1243 -z 62 n= ·IO ... n::: • o4 --~~~ 1 -7..70 h = •/O ~lfJeNT I se&meNI z '5£1':r/1)f3(1/{ ~ :fieGf'fJ~NT + ti D> .. ID . ~ • ~ us ~ t I V'1 ~ .~ ·~ .§ 2.,0 -t ... :.-11 :g .. CD ~ ts 0 g. a: ... >C = .. IO ts g. (") n n ::r • 0 ID ~ ts n ill" n rt ID c:: ... .. ~ ts DI c:: rt • ... g. 0 ~ ts .. ~ \ij 2>5 0 en "" ti Ill ........ ::r 0 D> 0 ID O' .. ~ 2 ID i:: 2 !' ........ 250 -+---------------,r-~~~~~~-;-~~~~~~~r-~~~~~~-,--~~~~~~~.----~~~~~~-.-~ Jj Ill c:-T ...... 0 ~ •3oo :1 I Ul ~ <t> <t> /000 1050 • I/ 00 I I 5() 11. 00 1250 S"fr;<Htft"I II'\ /~t---> r+
Appendix 10
worksheet
Base Plood Elevations in zone A Areas
state: -----
Community ID# =--------~Panel #: _____ FIRM Date: ________ _
Project Identifier
This request is for: Existing
Single Lot
Other
Proposed
Multi-Lot
<S acres
<SO lots
>S acres
>SO lots
-----------------------APPROACH USED TO DEVELOP THE BASE FLOOD ELEVATION (BFE)------------------
EXISTING DATA
SIMPLIFIED
DETAILED
FEMA
Federal
Other
Available
[ 1
[ 1
[ 1
Contour Interpolation ( ]
Not Available
[ 1
[ 1
[ 1
Did Not Check
[ 1
[ 1
[ 1
Data Extrapolation ( ]
Hydraulics Normal Depth [ ] Weir Flow [ ] Culvert Flow [ ]
Hydrology
Topography
Other ----------------------------
Regression Equations
Discharge-Drainage
Other
Rational Formula
TR-SS
----------------------------
Topographic Map ( or Field Survey
Map Scale: 1" = Contour Interval:
Field Survey tied to Datum? YES NO N/A
Datum: NGVD 1929 Other ---------------
# Cross-Sections Length of Stream--------ft.
------------------------------------------RESULTS-------------------------------------------
BFE or Depth of 100-year Flood
First Floor Elevation or Depth
Lowest Adjacent Grade to Structure
Lowest Grade on entire Property N/A
•U .S. GOVERNMENT PRINTING OFFICE: 1995-622-785/82189 . AlQ-1