HomeMy WebLinkAboutFolderFOR OFFICE USE ONLY
CASE NO. 0;)4 (o
DATE SUBMITTED Tl CYDft
SPECIAL DISTRICT
SITE PLAN APPLICATION
(Wolf Pen Creek, University Drive Corridor, and Northgate)
MINIMUM SUBMITTAL REQUIREMENTS
___£Site plan application completed in full. fi 200 ~ia..I ~i~~ c.f-
v $200.00 Application Fee . .s:fe.. Pla.n
-----V $200 .00 Development Permit Application Fee. ~ $300 .00 Public Infrastructure Inspection Fee if applicable. (This fee is payable if construction of a public
waterline, sewerline, sidewalk, street or drainage facilities is involved.) v Eighteen (18) folded copies of site plan.
· \;;/ Ten (10) folded copies of building elevations (including signage) with dimensions.
__::::_ Color and material samples. v A copy of the attached site plan checklist with all items checked off or a brief explanation as to why they are not
checked off.
APPLICANT (Primary Contact for the Project):
Name 13; \ \ Lo~\~'::/.
Street Address J 0 3 <:,/ o j ~
State T '/.._ Zip Code __.7--'7,_~.;:__46___;;_ __ _
Phone Number 'Y 1 °I -6 'f 6 -5( 4 l.
PROPERTY OWNER'S INFORMATION:
Name l3 ~ l \ (coo\~ \1
Street Address 5"6 3 G \ 6 .l (
State \ '/... Zip Code ---'l'-7"'"-~-4 _,O"----
Phon e Number '11 i; -' ~lo -SI 4 1.
ARCHITECT OR ENGINEER'S INFORMATION:
Name .J~~ S~\...-...\-\-<.. -Te_'{._(c...-\
City Cotl-e.j(. 5f o-h ....
E-Mail Address
City Lo I { ~, ~ Sf.J.'c..,
E-Mail Address
Street Address l 1 <::)] (., .--c-\t\c, ""' (2 o,. J City Co /{ e 5 c Sf-c-t,'o "'
State -C -e. -Lt) Zi p Code ] 7'd 4 5 E-Mail Address j()~ Sc..~J-b• Q hilt'"'·"' .. ~
Phone Number q 1 "( -G, q D -77 l \ Fax Number __ '\..:__].L_L'f_, =(;,'--'9-=-i)_,.__;.'?_1_;'f,_7L--------
OTHER CONTACTS (Please specify type of contact, i.e. project manager, potential buyer, local contact, etc.)
Name Qv...~'t'.V\ W~\l~c."""5 -
StreetAddress L..l l1 5h.t-i..-.wt>oJ Or;v< City Lolfc5c. Sfc.f;,,,....
State -r -c 'f.-~ ~ Zip Code :r1 ~A-0 E-Mail Address
Phone Number 9 J '\ -b Cf lo -tAA 4-Fax Number ---~=-->-f_G._-_'f.._-l:...."3_3 ______ _
SITE PLAN APPLICATION I of 3
Special District Site App.doc 05/01/02
PROPOSEDUSEOFPROPERTY_~~~~-\~_:_-~~-o_~_:_\_1~~~5_;_~-~~;._{~~~~~~~~~
VARIANCE(S)REQUESTEDANDREASON(S) P6r~-. .... <;) Sp6te5 -f/~": . .,..>f4 rt:~..,.,.Jfcc/
o. ...... J. 4ff<t>v~ J ~1 p~c_ OI'.\ rY\4-cJ.. Z...D, Z,oe> c.
1 /_ ..
#OF PARKING SPACES REQUIRED----'--'°---
MULTl-FAMIL Y RESIDENTIAL
Total Acreage tl. 3~ 1
Floodplain Acreage 0 . o
Housing Units 1--
1..k_ # of 1 Bedroom Un its
# of 2 Bedroom Units
#of 3 Bedroom Units
#of 4 Bedroom Units
FOR 2 BEDROOM UNITS ONLY
__ #Bedrooms= 132 sq . ft.
__ #Bedrooms < 132 sq. ft.
D ATTACHED SIGN
Square footage __ _
#OF PARKING SPACES PROVIDED __ z_o __ _
COMMERCIAL
Total Acreage ________ _
Building Square Feet ______ _
Floodplain Acreage _______ _
0 FREEST ANDING SIGN
Square footage __ _
The applicant has prepared this application and certifies that the facts stated herein and exhibits attached hereto are true
and correct.
5-/-o'-
Date
SITE PLAN APPLICATION 2 of 3
Special District Site App.doc 05101/02
(9-1.
Gr"' 2.
~ 3.
c:(
~
(!(
cY rr
if 4.
!SY"" 5.
er 6.
~ 7.
~
llr'"
a;r1
~ av
(4Y
~
C5Y
0 8.
l9'
ID"
[Y
13.Y"
aV
SUBMIT APPLICATION AND THIS
LIST CHECKED OFF WITH 10
FOLDED COPIES OF SITE PLAN FOR REVIEW
SITE PLAN MINIMUM REQUIREMENTS
(ALL CITY ORDINANCES MUST BE MET)
INCLUDING BUT NOT LI MITED TO THE FOLLOWING:
Sheet size -24" x 36" (minimum).
A key map (not necessarily to scale).
Title block to include:
Name, address, location, and legal description
Name, address, and telephone number of applicant
Name, address, and telephone number of developer/owner (if differs from applicant)
Name, address, and telephone number of architect/engineer (if differs from applicant)
Date of submittal
Total site area
North arrow.
Scale should be largest standard engineering scale possible on sheet.
Ownership and current zoning of parcel and all abutting parcels.
Existing locations of the following on or adjacent to the subject site:
Streets and sidewalks (R.O.W.).
Driveways (opposite and adjacent per Driveway Ordinance 1961 ).
Buildings.
Water courses.
Show all easements clearly designating as existing and type (utility, access, etc.).
100 yr. floodplain and floodway (if applicable) on or adjacent to the proposed project site, note if
there is none on the site.
Utilities (noting size and designate as existing) within or adjacent to the proposed site, including
building transformer locations, above ground and underground service con nections to buildings,
and drainage inlets.
Meter locations.
Topography (2' max or spot elevations) and other pertinent drainage information. (If plan has
too much information, show drainage on separate sheet.)
Proposed location, type and dimensions of the following .:
Phasing. Each phase must be able to stand alone to meet ordinance requirements.
The gross square footage of all buildings and structures and the proposed use of each . If
different uses are to be located in a single bui lding, show the location and size of the uses
within the building. Building separation is a minimum of 15 feet w/o additional fi re protection.
Setbacks. Show building setbacks as outlined in Ordinance 1638 Zoning Ord inance,
(Section 7, Table A).
Off-Street parking areas with parking spaces drawn, tabulated, and dimensioned. Minimum
parking space is 9' x 20', or on a perimeter row 9' x 18' with a 2' overhang. Designate number
of parking spaces required by ordinance and provided by proposa l.
Handicap parking spaces.
SITE PLAN CHECKLIST
SITECK.DOC 1/3/02
I of 3
NOTE:
~ 9.
Parki ng Islands. Raised landscape islands, (6 " raised curb) a minimum of 180 sq . ft. are
required at both ends of every parking row (greenspace area contiguous to the end island
maybe applied toward the req uired 180 sq . ft.). Additionally, 180 sq. ft. of landscaping for
every 15 interior parking spaces must be provided . All required islands must be landscaped or
set with decorative pavers, or stamped dyed concrete or other decorative materials as
approved .
Drives. Minimum drive aisle width is 23' with head-in parking or 20' without parking.
Curb cuts. For each proposed curb cut (including driveways, streets, alleys, etc.) locate existi ng
curb cuts on the same opposite sid e of the street to determine separation distances between
existing and proposed curb cuts. Indicate driveway throat length as measured in the Driveway
Ord inance. (See Ordinance 1961 for driveway location and design requirements.)
Security gates (show swing path and design specs with colors).
Sidewalks (both public and private). Sidewalks are required at time of development if property
has frontage on a street shown on the Sidewalk Master Plan or if the review staff determines
the necessity. (Refer to Section 10.2 of the Zoning Ordinance).
Medians. Show any and all traffic medians to be constructed on site.
Landscape Reserve. A twenty four foot setback from R.O.W. to curb of parking lot is required.
Pavement may encroach into this 24' reserve by up to 1134 square feet if streetscape
requirement can still be met. In no case may the pavement be less than 6' from the property
line.
Common open spaces sites
Loading docks
Detention ponds
Gu ardrails
Retain ing walls
All required and other types of fences (a 6' privacy fence is required between
industrial/commercial and residential developments as well as between multi-family and single
family developments).
Sites for sol id waste containers with screening. Locations of dumpsters are accessible but not
visible from streets or residential areas. Gates are discouraged and visual screening is
required. (Minimum 12 x 12 pad required.)
Show all easements clearly designating as proposed and type (utility, access, etc.). If dedicated
by separate instrument list by volume and page.
Utilities (noting size and designate as proposed) within or adjacent to the proposed site,
including building transformer locations, above ground and underground service connections to
buildings.
Meter locations (must be located in public R.O .W. or public utility easement.).
Proposed grading (1 ' max for proposed or spot elevations) and other pertinent drainage
information . (If plan has too much informati on , show drainage on separate sheet.)
Show proposed and existing fire hydrants. Fire hydrants must be located on the same side of a
major street as a project, and shall be in a location approved by the City Engineer. Any
structure in any zoning district other than R-1 , R-1 A, or R-2 must be within 300 feet of a fire
hydrant as measured along a public street, highway or designated fire lane.
Show fire department con nections. FDC's sh ould be within 150' of the fire hydrant. In no case
shall they be any fu rther than 300' apart, and they shall be accessible from the parking lot
without being blocked by parked cars or a structure .
Show fire lanes. Fire lanes a minimum of 20 feet in width with a minimum height clearance of
14 feet must be established if any portion of the proposed structure is more than 150 feet from
the curb line or pavement edge of a public street or highway.
Fire hydrants must be operable and accepted by the City, and drives must have an all weather
surface as defined in the Zoning Ordinance Section 9 before a building permit can be issued.
Will building be sprinkled? Yes D No ~
If the decision to sprinkle is made after th e site plan has been approved, then th e plan must be
resubmitted.
SITE PLAN CHECKLIST
SITECK DOC 1/3/02
2 or 3
10.
11 .
12.
13.
14.
a 15.
Q( 16.
17.
18.
19.
20.
NOTE:
Wheelstops may be required when cars overhang onto property not owned by the applicant or
where there may be conflict with handicap accessible routes or above ground utilities, signs or
other conflicts.
Show curb and pavement detail. A 6" raised curb is required around all edges of all parts of all
paved areas without exception. (To include island, planting areas, access ways, dumpster
locations, utility pads, etc.) Curb details may be found in the Zoning Ordinance Section 9 and
alternatives to those standards must be approved by the City Engineer. No exception will be
made for areas designated as "reserved for future parking".
Landscape plans as required in Section 11 of the Zoning Ordinance (See Ordinance# 1638.)
The landscaping plan can be shown on a separate sheet if too much information is on the
original site plan. If requesting protected tree points, then those trees need to be shown
appropriately barricaded on the landscape plan. Attempt to reduce or eliminate plantings in
easements. Include information on the plans such as:
required point calculations
additional streetscape points required . Streetscape compliance is required on all streets larger
than a residential street.
calculations for# of street trees required and proposed (proposed street tree points will accrue
toward total landscaping points.)
proposed new plantings with points earned
proposed locations of new plantings
screening of parking lots
screening of dumpsters, detention ponds, transformers, A/C units, loading docks, propane
tanks, utility demarcation point on buildings, or other areas potentially visually offensive.
existing landscaping to remain
show existing trees to be barricaded and barricade plan. Protected points wi ll only be awarded
if barricades are up before the first development permit is issued.
Show irrigation system plan. (or provide note on how irrigation system requirement will be met
prior to issuance of C.O.) All plans must include irrigation systems for landscaping. Irrigation
meters are separate from the regular water systems for buildings and will be sized by city
according to irrigation deman submitted by applicant and must include backflow prevention
protection.
Is there any landscaping in TxDOT R.O.W. ? Yes 0 No ~
If yes, then TxDOT permit must be submitted .
Will there be any utilities in TxDOT R.O.W. ? Yes D No CY
If yes, then TxDOT permit must be submitted .
Will there be access from a TxDOT R.O.W.? Yes D No ~
If yes, then TxDOT permit must be submitted .
The total number of multi-family buildings and units to be constructed on the proposed project
site.
The density of dwelling units per acre of the proposed project.
Provide a water and sanitary sewer legend to include water demands (minimum, maximum and
average demands in gallons per minute) and sewer loadings (maximum demands in gallons per
day).
Are there impact fees associated with this development? Yes O
Signs are to be permitted separately.
SITE PLAN CHECKLIST
SITECK DOC 1/3/02
3 of 3
SUPPLEMENTAL DEVELOPMENT PERMIT INFORMATION
Application is hereby made for the following development specific waterway alterations: ------------C.O~ !> \.t" J::ll_._ .r ~e~W\J g ... :l!:-.15 rrJ pkk:-~ lo r-
ACKNOWLEDGMENTS:
I, --~-b~~'--'l"f~k,~~-·-S-~_ ... _\._\._1. __ , design engineer/owner, hereby acknowledge or affirm that:
The information and conclusions contained in the above plans and supporting documents comply with the current
requirements of the City of College Station, Texas City Code, Chapter 13 and its associated Drainage Policy and Design
Standards. As a condition of approval of this permit application, I agree to construct the improvements proposed in this
application according to these documents and the requirements of Chapter 13 of the Colleg Sta ·on ity Code.
{)_
Property Owner(s) Contr. tor ~
CERTIFICATIONS: (for proposed alterations within designated flood hazard areas.)
A. I, , certify that any nonresidential structure on or proposed to be on this site as
part of this application is designated to prevent damage to the structure or its contents as a result of flooding from the 100
year storm.
Engineer Date
B. I, , certify that the finished floor elevation of the lowest floor, including any
basement, of any residential structure, proposed as part of this application is at or above the base flood elevation
established in the latest Federal Insurance Administration Flood Hazard Study and maps, as amended.
Engineer Date
Conditions or comments as part of approval: ____________________________ _
In accordance with Chapter 13 of the Code of Ordinances of the City of College Station , measures shall be taken to insure
that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage
facilities.
I hereby grant this permit for development. All development shall be in accordance with the plans and specifications
submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances
of the City of College Station shall apply.
SITE PLAN APPLICATION 3 of3
Special District Site App.doc 05/0 1/02
• 1 ..
• ~f • •
; '
.
' ' ,, 1. ·;I'
! ., ...
J ...
STAFF REVIEW COMMENTS NO. 1
Project: DP-NORTHGATE LOFTS-DEVELOPMENT PERMIT (02-00100026)
ENGINEERING
1. As you know, this area is a mandatory detention area. Please show how this
requirement is to be met on this project.
2. Is a culvert required for this project?
3. Please explain how a 1" meter is needed for 1 GPM flow.
4. For a DP, please show erosion control.
5. Please label #17 as irrigation meter and backflow preventer.
6. Drainage will not be allowed to negatively impact surrounding properties. Please
demonstrate that drainage from the southwest corner of the parking lot will not
create a problem.
Reviewed by: Spencer Thompson Date: May 13, 2002
NOTE: Any changes made to the plans, that have not been requested by the City of College Station, must be explained in your
next transmittal letter and "bubbled" on your plans. Any additional changes on these plans that have not been pointed out
to the City, will constitute a completely new review.
Page 2 of 2
. ' '
FILE
"'" ........ .
Design Report
Waterline Fire Flow Analysis
for
N orthgate Lofts
Tauber Street
College Station, Texas
June 2002
Prepared By:
TEXCON General Contractors
1707 Graham Road
College Station, Texas 77845
(979) 690-771 I
REVIEWED FOR
COMPLIANCE
COLLEGE STATION
ENGINEERING
~~.:::~ .. ~,,,.~·~·"\).
-"\t. i_.r 1·\, ;~'r ·, ... ,. .. <:~1-\~
--0 •• * .. -<J dl ,,,, ••• • ' • •• 15' '• "* .. ' ·. . ~ . . • * v,. ~ * • ' . l,f, ~.................. • * 'I l JOSEP .................. ,.
............. ~ •• ~: •• SCHULTZ ~ l,1;...,-9 658 ......... ?.'f J f ,,(\·~c ~117 4 (:' '• IST •• ~ _.., .
~·
b--(7--DZ
1.0 INTROD UCT ION & DESCRIPTION
The purpose of this report is to provide a description of the ex isting and proposed wa terline
fo r the Nortltgate lofts proj ect, and to provide th e res ults of the analysis of th e waterlines
und er fire fl ow conditions. An ex isting 2'" waterline is located along Tauber Street in fro nt
of the project site. The proposed 6'' waterline to suppl y the fire hydrant fo r the site will
connect to an 8 .. waterline stub currentl y being constru cted fo r the Cherry Street
Rehabilitation Proj ect. The 6 .. waterline for this project will be constru cted of DR-14,
PVC pipe meeting the requirements of A WW A C-900 with mechanical joint fittin gs. The
proposed wate rline to supply the fire sprinkl er system will be a 2" diameter line connected
to the proposed 2" water meter which will be installed on the existing 2'" waterline along
Tauber Street. This 2" line will also supply the domestic water for each building. A 2"
meter and waterlin e wi ll be constructed for each of the buildings.
2.0 FIRE FLOW REQUIREMENTS
The flow required for fire hydrant flow for the project is 969 gallons per minute (gpm), as
shown on Ex hibit 1. We have used this va lue for this analysis. The fire sprinkler sys tem
peak demand is 80 gallons per minute {gpm). This valu e was provided by Standard
Automatic Fire Enterprises.
3.0 WATERLINE SYSTEM ANALYSIS
A pressure/f1ow test was performed on a fire hydrant on an ex isting 6'' waterline to
determine the pressure and flo w avail able in this area for use in thi s analysis. This test was
perfonned by Standard Automatic Fire Enterprises, and the results are as follows :
Static Pressure
Residual Pressure
70 psi
65 psi @ flow of 1,090 gpm
The design flo w for the proposed 6'. water main extension is the sum of the fire flow and
th e normal domestic use demand on the ex isting waterline. The fire flo w demand is 969
gpm fo r the fire hydrant flow and 80 gpm for the sprinkler system. The nonnal demand
was ass um ed to be 8 existing residential units and 8 proposed residenti al units at a flow of
2 gpm each for a total of 32 gpm . The design flow for the 6" lin e is 1,081 gpm, which is
almost identical to the 1,090 gpm flow in the pressure tes t. Therefore, a residual pressure
of 65 psi is used in the anal ysis for the start of the 6" lin e.
Using the Hazen-Williams Equation with a C value of 140 fo r th e 6 .. pipe, the head loss in
180 feet of pipe is 6 psi. The veloc ity in th e 6 .. pipe is 12.J fp s. The residual pressure at
the fire hydrant will be 59 psi .
There wi ll be approximately 250 feet of ex istin g 2'" wa terline from the proposed fire
hydrant to the water supply lin e for the proposed building. An additional I 0% of length is
added for minor losses due to fittings, va lves and the meter. AC va lu e of 140 was used for
the ex isting pipe. The head loss in the 2'" pipe is 28 psi at a veloc ity of 11.5 fp s. The
residual press ure in th e ex isting 2 .. \Vaterlinc at the proj ec t si te is 3 1 psi . which exceeds th e
minimum pressure of 20 psi required by the TNRCC.
'
The above analysis is based on th e assumption that the fire hydrant, fire sprinkler and
nom1 al demand nows are all occurrin g at the same tim e. rr only th e fire sprinkler and
normal demand flo w are considered, the head loss in the 6 .. line will be minimal and the
residual pressure in the 2'" line at the project site will be approximately 37 psi.
This analysis primari ly addresses the fir e flow req uirements for the Phase I building for
the project. Upon completion of the proposed water! i ne improvements, additional
pressure/flow tests should be performed to verify the design assumptions used in this
analysis.
4.0 CONCLUSIONS
The analysis of the waterlines presented herein is conservative because the pressure loss in
the waterlines was evaluated assuming the project site is supplied only from the north by
the existing 6" line or proposed 8'' line on C herry Street. The existing 2" waterline
connects to 2-2" waterlines approximately 180 feet to the south at the intersection of
Tauber and Cross Streets. If these lines were considered in the design analysis, the
residual pressure would be greater than the values determined by this analysis. In
summary, there is adequate water flow and pressure in the existing 2" waterline under fire
fl ow conditions. This conclusion is based on the assumption that 180 feet of 6" water main
wi ll be constructed from Cherry Street toward the proj ect si te along Tauber Street. If thi s
does not occur, additional analysis using additional data would need to be perfom1ed.
2
Determination of Fire Flow
Fire Flow = F = 18C{/\ (gpm)
EXHlBIT l
Northgate Lofts
Tauber Street
College Station. Texas
C =Coefficient related to the type of construction
1.0 for ordinary construction
0.8 for noncombustible construction
0.6 for fire-resistive construction
A = Total floor area of building (SF)
F = l8Cv'A(gpm) C=l.O A=4,6l 7 SF
F = 18(1.0) '14,6 17 SF = l,223 gpm
Round up or down to increments of 250 gpm
F = 1,250 gpm
Reduce F by 50% for automatic sprinkler system
F = l ,250*0.50 = 625 gpm
Addition of exposure protection
Separation Distance
lOl '-150' (I side)
61'-100' (I side)
31 '-60' (!side)
0 '-10' (l side)
Add 55% to Fire Flow
Percentage
5%
10%
15 %
25%
55%
F = 625 gpm + (0.55)(625) = 969 gpm
F = 969 gpm -Fire Hydrant Flow
Fire Sprinkler System Flow = 80 gpm
.'
DEVELOPMENT PERMIT
PERMIT NO. 02-26
Project: NORTH GA TE LOFTS
FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA
RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE
SITE LEGAL DESCRIPTION:
BOYETT BLOCK 4
LOTS 12, 13, 14
DATE OF ISSUE: 6/25/02
OWNER:
BILL COOLEY
503 GLADE
CS, TX 77840
TYPE OF DEVELOPMENT:
SPECIAL CONDITIONS:
SITE ADDRESS:
403-409 TAUBER
DRAINAGE BASIN:
Burton Creek
VALID FOR 9 MONTHS
CONTRACTOR:
Full Development Permit
All construction must be in compliance with the approved construction plans
All trees must be barricaded, as shown on plans, prior to any construction. Any trees not barricaded will not
count towards landscaping points. Barricades must be 1' per caliper inch of the tree diameter.
The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate
construction site in accordance with the approved erosion control plan as well as the City of College Station
Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are ineffective
to retain all sediment onsite, it is the contractors responsibility to implement measures that will meet City, State
and Federal requirements. The Owner and/or Contractor shall assure that all disturbed areas are sodden and
establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion
control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original
condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to
adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion,
siltation or sedimentation resulting from the permitted work.
Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced
before any operations of this permit can begin.
In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be
taken to insure that debris from construction , erosion, and sedimentation shall not be deposited in city streets,
or existing drainage facilities.
I hereby grant this permit for development of an area outside the special flood hazard area. All development
shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the
development permit application for the above named project and all of the codes and ordinances of the City of
College Station that a ply. ·
Datet I
Owner/ Agent/Contractor Date
CERTIFICATION
REVIEWED FOR
I, Joseph P. Schultz, Licensed Professional Engineer No. 65889, State of Te as, · t C
report for the drainage design for the Northgate Lofts development was pre are by me in
accordance with the provisions of the City of College Station Drainage Poli y and D hlMn2;t3~'Xl.Cl~--.lt~
for the owners hereof.
_,,,,,,,
--"'ic OF -,. \\
"" 'i>-•••••••• ~.+: '• , 0 •• •••• ·····.:iS' •• ~· •" ... *,A ~ *. . *".ii ~·····························,·····i ~ .. AQ~~f.tl .. ~; .. ~~.~.Y.~T~ .... J l.~. • Q; /!. "~-:P0\ .L\ 65889 : "'i! ., ·~r~ Q•"Wi' .,,~~··9./STE~«i.•;§' I
'
vs, ....... ~v.,•
\ .. ,,.C?NAL ~-,,,~._.
COLLEGE STATION
ENGINEERING
TABLE OF CONTENTS
NORTHGATE LOFTS
CERTIFICATION ............................................................................................................................................................ 1
TABLE OF CONTENTS .................................................................................................................................................. 2
LIST OFT ABLES ............................................................................................................................................................ 3
INTRODUCTION ............................................•................................................................................................................ 4
GENERAL LOCATION AND DESCRIPTION .....................................•...................................................................... 4
FLOOD HAZARD INFORMATION ............................................................................................................................. .4
DEVELOPMENT DRAINAGE PATTERNS .........................................•..•................................................................... .4
DRAINAGE DES IGN CRITERIA ...............•........................................•........................................................................ .4
STORM WATER RUNOFF DETERMINATION .............................................................................................•........... S
DETENTION FACILITY DESIGN ................................................................................................................................ 6
CONCLUSIONS ................................................................................................................................................................ 7
APPENDIX A .................................................................................................................................................................... 8
Detention Pond I
-JOO-Year Storm Hydrograph
-Area I Capacity Data & Storage Depth vs. Volume Graph
-Depth I Discharge Data & Rating Curve for Outlet Structure
-Storage Routing Analysis
EXHIBIT A ...................................................................................................................................................................... 18
Pre-Development Drainage Area Map
EXHIBIT B ...................................................................................................................................................................... 20
Post-Development Drainage Area Map
2
LIST OF TABLES
TABLE I -Rainfall Intensity Calculations ......................................................................................... 5
TABLE 2 -Pre and Post-Development Flow ...................................................................................... 6
TABLE 3 -Post-Development Detention Pond Flow Information ..................................................... 6
J
INTRODUCTION
DRAINAGE REPORT
NORTHGATE LOFTS
The purpose of this report is to provide the hydrological effects of the construction of the
Northgate Lofts, and to show that the detention facility proposed for this site will control the
storm water runoff in such a manner so as to have no offsite or downstream impact.
GENERAL LOCATION AND DESCRIPTION
The project is located on a 0.397 acre tract located on Tauber Street north of University
Dri ve in the Northgate area of College Station, Texas. The site currently has four I -story
wood frame duplex units located on it. These structures will be removed during the various
stages of the construction. The existing ground elevations range from elevation 351 to
elevation 353. The general location of the project site is shown on the vicinity map in
Exhibit A.
FLOOD HAZARD INFORMATION
The project site is located in the Burton Creek Drainage Basin. The site is located in a Zone
X Area according to the Flood fnsurance Rate Map prepared by the Federal Emergency
Management Agency for Brazos County, Texas and incorporated areas dated July 2, 1992,
panel number 48041COl42C. A Zone X Area is in an area detennined to be outside of the
500-yr floodplain .
DEVELOPMENT DRAINAGE PATTERNS
The storm water runoff from the site prior to development generally flows to the north
towards Tauber Street where it runs along Tauber Street until it reaches the existing storm
sewer system on Cherry Street. A portion of the runoff also flows to the southwest onto the
adjacent property.
After the proposed development, the proposed detention pond will capture a majority of the
storm water runoff from the site. The locations of this structure as well as the post
development drainage area boundaries are shown in Exhibit B. Because of this detention
pond, the post-development runoff will be controlled and released at or below the runoff
rates allowed for this development. The design criteria and calculations are included in
subsequent sections of this report.
DRAINAGE DESIGN CRITERIA
The design parameters for the stom1 sewer system and detention facility are as follows:
• The Rational Method is utilized to determine peak storm water runoff rates for th e storm
sewer design. A Storage Routing Analys is based on the Continuity Equation is used to
determine the peak f1ow out of the detention facility.
• Design Storm Frequency
Detention Pond 5, 10, 25, 50, and 100-year storm events
• Runoff Coefficients
Grass & landscaped areas
Gravel parking areas
Concrete pavement & building rooftops
c = 0.40
c = 0.80
c = 0.90
• Rainfall Intensity val ues for Brazos County for a minimum time of concentration of 10
minutes can be found in Table 1.
• Time of Concentration, 4: -Due to the small sizes of the drainage areas, the majority of
the calculated times of concentration, tc, are less than 10 minutes. Therefore, a minimum
tc of l 0 minutes is used to determine the rainfall intensity. Refer to Table l for
equations.
STORM WATER RUNOFF DETERMINATION
The peak runoff values were determined in accordance with the criteria presented in the
previous section for the 5, 10, 25 , 50, and 100-year storm events. The runoff coefficients are
based on the future development of this tract. The peak runoff values used for calculating
the allowable post-development runo ff conditions are shown in Table 2. These values are
based on a weighted average of the runoff coefficients given above. The actual post-
development runoff from the detention pond is summarized in Table 3.
TABLE 1 -Rainfall Intensity Calculations
Rainfall Intensity Values (in/hr)
Storm t.:=
Event 10 min
Is 7.693
110 8.635
125 9.861
150 11.148
1100 11.639
Brazos County:
5 t:ear storm 10 t:ear storm
b = 76 b = 80
d = 8.5 d = 8.5
e = 0.785 e = 0.763
The Rational Method:
Q=CIA
Q = Flow (cfs)
A = Area (acres)
C = Runoff Coeff.
I = b I (tc+d)e
tc = L/(V*60)
tc = Time of concentration (min)
L = Length (ft)
I = Rainfall Intensity (in/hr) V =Velocity (ft/sec)
25 t:ear storm 50 t:ear storm 100 t:ear storm
b = 89 b = 98 b = 96
d = 8.5 d = 8.5 d = 8.0
e = 0.754 e = 0.745 e = 0.730
(Data taken from State Department of Hiqhwat:s and Public Transportation Ht:draulic Manual. page 2-16)
5
TABLE 2 -Pre and Post-Deve lopment Flow
Area c tc Os 010 02s Oso 0100 Area# (square feet) (acres) c, C2 C3 C4 Crotal
A, -Buildina A2 -Gravel Al -Concre1e ~-Grass Total Total (min) (cfs) (cfs) (cfs) (cfs) (cfs)
Pre-Development Runoff Information
A 2420 567 605 5367 8959 0.2057 0.90 0.80 0.90 0.40 0.59 10 0.94 1.06 1.20 1.36 1.42 -0.85 0.97 --,___
B 1765 42 135 6370 8312 0.1908 0.90 0.80 0.90 0.40 0.52 10 0.76 1.10 1.15
4185 609 740 11737 17271 0.3965
Post-Develoment Runoff Information
1 2886 0 7030 1595 11511 0.2643 0.90 0.80 0.90 0.40 0.83 10 1.69 1.90 2.16 2.45 2.56 ,_
3 0 0 0 383 383 0.0088 0.90 0.80 0.90 0.40 0.40 10 0.03 0.03 0.03 0.04 0.04
4 546 0 155 1947 2648 0.0608 0.90 0.80 0.90 0.40 0.53 10 0.25 0.28 0.32 0.36 0.38
5 183 0 132 1648 1963 0.0451 0.90 0.80 0.90 0.40 0.48 10 0.17 0.19 0.21 0.24 0.25
6 363 0 0 511 874 0.0201 0.90 0.80 0.90 0.40 0.61 10 0.09 0.11 0.12 0.14 0.14
3978 0 7317 6084 17379 0.3990
TABLE 3 -Post-Development Detention Pond Flow Information
Detention Areas Os 010 02s Oso 0100
(cfs) (cfs) (cfs) (cfs) (cfs)
Pond #1
Pre-Devel. Offsite Flow (cfs) (Area A) 0.9 1 .1 1.2 1.4 1.4 -------·-·------·-· --------------Post-Devel. Offsite Flow (cfs) (Areas 3 & 6) 0.1 0.1 0.2 0.2 0.2 -------------------. -----Pre-Devel. Offsite Flow (cfs) (Area 8) 0.8 0.9 1.0 1.1 1.2 --------· -----------------~ ---Post-Devel. Offsite Flow (cfs) (Areas 4 & 5) 0.4 0.5 0.5 0.6
TOTAL Pre-Devel. Offsite Flow (cfs) 1.7 1.9 2.2 2.5 --------------------------Post-Devel. Offsite Flow (cfs) (A:eas 3. 4. 5 & 6) 0.5 0.6 0.7 0.8 ·----·------->--------------1------------· -Pond OMAx Out -Allowed (cfs) 1.2 1.3 1.5 1.7 -------· -----Pond QMAX Out -Actual (cfs) 1.1 1.2 1.3 1.4 -----Pond QMAX In (cfs) (Area 1) 1.7 1.9 2.2 2.4 --TOTAL Post-Devel. Offsite Flow (cfs) 1.6 1.8 1.9 2.1 -----
Maximum Water Surface Elevation (ft) 352.48 352.52 352.56 352.62 -------------Pond Freeboard (ft) 0.72 0.68 0.64 0.58 ---------Top of Berm Elevation (ft) = 353.2
DETENTION FACILITY DESIGN
The peak runoff rates for the post-development conditions will be reduced to less than the
allowable peak rates for the post-development conditions by temporarily impounding a
portion of the runoff in th e proposed pond. The flow out of the pond is controlled by the 8"
diameter PVC o utlet pipe. As shown in Table 3, the post-development flo w after routin g th e
runoff through Pond 1 is less than th e pre-development flow. For the 10-, 25-, 50-and 100-
year the post-development runoff values do not increase from the post-development values.
These results show that the proposed pond will e ffecti vely control the post-development
peak runoff levels at or below the a llowable levels determined by the pre-development
conditions. An increase in post-development off-site flow is avoided by di verting a majority
of the stom1water runoff to the pond, thereby reducing the area draining directl y off site. A
portion of th e parking lot is uti lized for th e Pond I storage volume. At the max imum water
6
0.6
2.6 ----
0.8 ----1.8
1.4
2.6 -2.2
352.65
0.55
surface elevation of 352.65 feet for the I 00-year storm event, the depth of water in the
lowest corner of the parking lot will be 0.60 feet. The runoff values draining off site, as well
as into the proposed pond are summarized in Table 3. Refer to Exhibit A for the pre-
development drainage areas, and Exhibit B for the post-development drainage areas.
A graphical representation of the Area/Capacity data and the Depth/ Discharge data are
provided in Appendix A. The peak flow out of the detention pond was determined by a
Storage Routing Analysis based on the Continuity Equation as follows: (l l +l2)+((2s l/dt)-
O l )=((2s2/dt)+02). The time interval, dt, used was l minute. The results of the Storage
Routing Analysis are also provided in Appendix A.
CONCLUSIONS
The construction of this project will increase the storm water runoff from this site.
However, the proposed detention pond will adequately control the actual post-development
runoff to levels lower than the allowable runoff for this site. No flood damage to
downstream landowners is expected as a result of this development.
7
APPENDIX A
Detention Pond 1
-100-Year Storm Hydrograph
-Area I Capacity Data & Storage Depth vs. Volume Graph
-Depth I Discharge Data & Rating Curve for Outlet Structure
-Storage Routing Analysis
8
Northgate Lofts
Pond #1 -100 Year Storm Hydrograph -Revised
4.00
QMAX-post = 3.37
3.50 I
3.00 .
Volume = 720 ft3 + 10% = 792 ft3
2.50
~ ~ a
i 2.00 .2 u.
.>e. OI GI 0.. OMAX-pre= 2.57 cfs
1.50 .
100 .
0.50
000 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0 10 20 30
Time of Concentration, tc (min)
3,500
3,000
2,500
E
0
.c 2,000
::I
0 -Q) 5 1,500
0 >
1,000
500
Elevation
(ft)
351.7
352
352.25
352.5
352.75
353
Northgate Lofts
Pond 1 -Revised
Area -Capacity Data
Depth Area Volume
(ft) (ft2) (ft3)
0
0 8.6
86
0.3 88.9
730
0.55 392.9
2,606
0.8 956.7
5.195
1.05 1,601 .2
7,696
Storage Depth vs. Volume
Cumulative
Volume
(ft3)
9
97
490
1,447
3,048
olt-=========~~~~~~~~~~~~~~~_J
0.00 0.30 0.55
Depth (ft)
0.80 1.05
Northgate Lofts
Pond 1 -Revised
Depth -Discharge Data
Elevation Depth Flow
(ft) (ft) (cfs)
351 .70 000 0 00
352.00 0.30 0.23
352.25 0.55 0.68
352.50 0.80 1.13
352.75 1.05 1.52
353.00 1.30 1.82
The depth-discharge data for Pond 1 is based on a circular channel with
the energy head equal to the depth for open channel flow and using the
culvert equation for depths greater than the diameter of the pipe to
determine the flow at each depth.
Rating Curve for Outlet Structure
Depth vs. Discharge
2.00 -------·----
1.80
1.60
-1.40
Ill -u i 1.20
0
LL 1.00 Q)
Cl ...
IV 0.80 J::. u
Ill
0 0.60
0.40
0.20 ---------
0.00
0.30 0.55 0.80 1.05
Depth (ft)
1.30
Northgate Lofts
Storage Routing Analysis Parameters
Pond 1 -8" PVC Pipe
Elevation Depth Discharge Storage S,
(ft) (ft) (cfs) (cf) 2 sit 2 sit+ 0
351 .70 000 0.00 0.00 0.00 0.00
352.00 0.30 0.23 8.60 0.29 0.52
352.25 0.55 0.68 88.88 2.96 3.64
352.50 0.80 1.13 392.94 13.10 14.23
352.75 1.05 1.52 956.70 31 .89 33.41
353.00 1.30 1.82 1601 .17 53.37 55.19
t = 60
Northgate Lofts Storage Routing Analysis Pond 1 -Revised 5-Year Storm Event Time Inflow 11+12 Outflow (min.) (cfs) (cfs) 2s/t-0 2s/t+O (cfs) Depth (ft.) Elevation 0 0.00 0.00 0.00 0.00 0.00 0.00 351.70 1 0.17 0.17 0.02 0.17 0.07 0.16 351.86 2 0.34 0.51 0.06 0.53 0.23 0.32 352.02 3 0.51 0.85 0.34 0.91 0.29 0.36 352.06 4 0.68 1.18 0.77 1.52 0.37 0.41 352.11 5 0.85 1.52 1.32 2.29 0.49 0.47 352.17 6 1.01 1.86 1.95 3.18 0.61 0.48 352.18 7 1.18 2.20 2.75 4.15 0.70 0.60 352.30 8 1.35 2.54 3.78 5.28 0.75 0.64 352.34 9 1.52 2.87 5.04 6.66 0.81 0.66 352.36 10 I 1.69 I 3.21 6.50 8.25 0.88 0.69 352.39 11 1.61 3.30 7.91 9.79 0.94 0.72 352.42 12 1.52 3.13 9.05 11.04 0.99 0.74 352.44 13 1.44 2.96 9.93 12.01 1.04 0.76 352.46 14 1.35 2.79 10.59 12.72 1.07 0.77 352.47 15 1.27 2.62 11.04 13.21 1.09 0.78 352.48 16 1.18 2.45 11.29 13.49 I 1.10 0.78 352.48 I 17 1.10 2.28 11.37 13.57 1.10 0.78 352.48 18 1 01 2.11 11.28 13.48 1.10 0.78 352.48 19 0.93 1.94 11.05 13.23 1.09 0.78 352.48 20 0.85 1.77 10.69 12.83 1.07 0.77 352.47 21 0.76 1.61 10.20 12.29 1.05 0.76 352.46 22 0.68 1.44 9.59 11.63 1.02 0.74 352.44 23 0.59 1.27 8.89 10.86 0.99 0.74 352.44 24 0.51 1.10 8.09 9.99 0.95 0.72 352.42 25 0.42 0.93 7.20 9.02 0.91 0.71 352.41 26 0.34 0.76 6.23 7.96 0.86 0.68 352.38 27 0.25 0.59 5.19 6.82 0.82 0.66 352.36 28 0.17 0.42 4.09 5.62 0.76 0.65 352.35 29 0.08 0.25 2.92 4.34 0.71 0.60 352.30 30 0.00 0.08 1.83 3.01 0.59 0.53 352.23 31 0.00 0.00 0.99 1.83 0.42 0.44 352.14 32 0.00 0.00 0.40 0.99 0.30 0.36 352.06 33 0.00 0.00 0.05 0.40 0.18 0.27 351.97 34 0.00 0.00 0.01 0.05 0.02 0.10 351.80 35 0.00 0.00 0.00 0.01 0.00 0.00 351.70 pond 1-8in-pipe-rev xis
Northgate Lofts
Storage Routing Analysis
Pond 1 -Revised
10-Year Storm Event
Time Inflow 11+12 Outflow
(min.) (cfs) (cfs) 2s/t-0 2s/t+O (cfs) Depth (ft.) Elevation
0 0.00 0.00 0.00 0.00 0.00 0.00 351 .70
1 0.19 0.19 0.02 0.19 0.08 0.17 351 .87
2 0.38 0.57 0.11 0 59 0.24 0 32 352.02
3 0.57 0.95 0.45 1.06 0.31 0.37 352.07
4 0.76 1.33 0.95 1.78 0.41 0.43 352.1 3
5 0.95 1. 71 1.58 2.66 0.54 0.50 352.20
6 1.14 2.09 2.31 3.67 0.68 0.57 352.27
7 1.33 2.47 3.32 4.78 0.73 0.63 352.33
8 1.52 2.85 4.60 6.17 0.79 0.66 352.36
9 1. 71 3.23 6.11 7.83 0.86 0.68 352.38
10 1.90 3.61 7.85 9.72 0.94 073 352.43
11 1.81 3.71 9.52 11.55 1.02 0.74 352.44
12 1.71 3.52 10.88 13 03 1.08 0 77 352.47
13 1.62 3.33 11 .94 14.20 1.13 0.80 352.50
14 1.52 3.14 12.78 15.08 1.15 0.81 352.51
15 1.43 2.95 13.41 15.73 1.16 0.82 352.52
16 1.33 2.76 13.82 16.16 1.17 0.82 352.52
17 1.24 2.57 14.04 16.39 1 17 0.82 352.52
18 1.14 2.38 14.07 16.42 1.17 0.82 352.52
19 1.05 2.19 13.91 16 25 1 17 0.82 352.52
20 0.95 2 00 13.58 15.91 1.16 0.82 352.52
21 0.86 1.81 13.08 15.38 1.15 0.81 352.51
22 076 1.62 12.41 14.69 1.14 0.81 352.51
23 0.67 1.43 11 .61 13.84 1.11 07 9 352.49
24 0.57 1.24 10.70 12.84 1 07 0.77 352.47
25 0.48 1.05 9.70 11 .75 1.02 0.74 352.44
26 0.38 0.86 8.61 10.55 0.97 0.73 352.43
27 0.29 0.67 7.43 9.27 0.92 0.71 352.41
28 0.19 0.48 6.18 7.91 0.86 0.68 352.38
29 0.10 0.29 4.87 6.47 0.80 0.66 352.36
30 0 00 0.10 3.49 4.96 0.74 0.64 352.34
31 0.00 0.00 2.17 3.49 0.66 0.55 352.25
32 0.00 0.00 1.24 2.17 0.47 0.46 352.16
33 0 00 0.00 0.57 1.24 0.33 0.38 352.08
34 0.00 0.00 0.10 0.57 0.24 0.32 352.02
35 0.00 0.00 0.01 0.10 0.04 0.13 351 .83
36 0.00 0.00 0.00 0.01 0.00 0.00 351 .70
37 0.00 0.00 0.00 0.00 0 00 0 00 351 .70
38 0.00 0 00 0 00 0 00 0 00 0.00 351 70
39 0.00 0.00 0.00 0 00 0 00 0.00 351 70
40 0.00 0.00 0.00 0 00 0 00 0 00 35170
pond 1-8in-pipe-rev .xis
Northgate Lofts
Storage Routing Analysis
Pond 1 -Revised
25-Year Storm Event
Time Inflow 11+12 Outflow
(min.) (cfs) (cfs) 2s/t-0 2s/t+O (cfs) Depth (ft.) Elevation --
0 0.00 0 00 0.00 0.00 0.00 0.00 351 .70
1 0.22 0.22 0.02 0.22 0.10 0.20 351 .90
2 0.43 0.65 0.17 0.67 025 0.33 352.03
3 065 1.08 0.58 1 25 0.34 0.39 352 09
4 0.86 1.51 1.18 2 09 0.46 0.46 352 .16
5 1.08 1.94 1.91 3.12 0.61 0.48 352.18
6 1.30 2.38 2.87 4.29 0.71 0.60 352.30
7 1.51 2.81 4.15 5.68 0.77 0.66 352.36
8 1.73 3.24 5.71 7.39 0.84 0.67 352.37
9 1.94 3.67 7.53 9.38 0.92 0.71 352.41
10 2.16 4.10 9.60 11 .64 1.02 0.74 352.44
11 2.05 4.21 11 .58 13.81 1 .11 0.79 352.49
12 1.94 4.00 13.27 15.58 1.16 0.82 352 .52
13 1.84 3.78 14.67 17.05 1 19 0.83 352 .53
14 1.73 3.56 15.81 18.24 1.21 0.83 352 .53
15 1.62 3.35 16.70 19.16 1.23 0.84 352 .54
16 1.51 3.13 17.34 19 83 1.24 0.85 352.55
17 1.40 2.92 17.75 20.26 1.25 0.85 352.55
18 1.30 2.70 17.94 20.45 1.26 0.86 352.56
19 1.19 2.48 17 91 20.43 1.26 0.86 352 .56
20 1.08 2.27 17.68 20.18 1.25 0.85 352 .55
21 0.97 2.05 17.25 19 73 1.24 0.85 352 .55
22 0.86 1.84 16.63 19 08 1.23 0 84 352.54
23 0.76 1.62 15 82 18.25 1.21 0.83 352.53
24 0.65 1.40 14.85 17.23 1.19 0.83 352.53
25 0.54 1.19 13.70 16.03 1.17 0.82 352 52
26 0.43 0.97 12.39 14.67 1.14 0.81 352.51
27 0.32 0.76 10.93 13.15 1.11 0.79 352.49
28 0.22 0.54 9.33 11.47 1.07 0.77 352.47
29 0 11 0.32 7.78 9.65 0.94 0.73 352.43
30 0.00 0.11 6.17 7.89 0.86 0.68 352.38
31 0.00 0.00 4.59 6.17 0.79 0.66 352.36
32 0.00 0.00 3.15 4.59 0.72 0.61 352.31
33 0.00 0.00 1.93 3.15 0.61 0.48 352.18
34 0.00 0.00 1 06 1.93 0.43 0.44 352.14
35 0.00 0.00 0.45 1 06 0.31 0.37 352.07
36 0.00 0.00 0 05 0.45 0 20 0.29 351 .99
37 0.00 0.00 0.01 0.05 0 02 0.10 351 .80
38 0.00 0.00 0 00 0 01 0.00 0 00 351 70
39 0.00 0.00 0.00 0 00 0.00 0 00 351 .70
40 0 00 0 00 0 00 0 00 0 00 0 00 351 7 0
pond 1-8in-pipe-rev. xis
Northgate Lofts
Storage Routing Analysis
Pond 1 -Revised
50-Year Storm Event
Time Inflow 11+12 Outflow
(min.) (cfs) (cfs) 2s/t-0 2s/t+O (cfs) Depth (ft.) Elevation
0 0.00 0.00 0.00 0.00 0.00 0.00 351 .70
1 0.25 0.25 0.03 0.25 0.11 0.21 351 .91
2 0.49 0.74 0.23 0.76 0.27 0.34 352.04
3 0.74 1.23 0.73 1.46 0.37 0.41 352.11
4 0.98 1.72 1.43 2.44 0.51 0.48 352.18
5 1.23 2.21 2.27 3.63 0.68 0.57 352.27
6 1.47 2.70 3.50 4.97 0.74 0.64 352.34
7 1.72 3.19 5.06 6.68 0.81 0.66 352.36
8 1.96 3.68 6.95 8.74 0.90 0.70 352.40
9 2.21 4.17 9.12 11 . 11 1.00 0.73 352.43
10 2.45 4.66 11 .55 13.77 1.11 0.79 352.49
11 2.33 4.78 13.98 16.33 1.17 0.82 352.52
12 2.21 4.53 16.08 18.51 1.22 0.84 352.54
13 2.08 4.29 17.86 20.37 1.25 0.85 352.55
14 1.96 4.04 19.33 21 .90 1.29 0.88 352.58
15 1.84 3.80 20.50 23.13 1.31 0.90 352.60
16 1.72 3.55 21.40 24.06 1.33 0.91 352.61
17 1.59 3.31 22.02 24.70 1 34 0.92 352.62
18 1.47 3.06 22.38 25.08 1.35 0.92 352.62
19 1.35 2 82 22.49 25.20 1.35 0.92 352.62
20 1.23 2.57 22.36 25.06 1.35 0.92 352.62
21 1.10 2.33 22.01 24.69 1 34 0.92 352.62
22 0.98 2.08 21.43 24 09 1 33 0.91 352.61
23 0.86 1.84 20.64 23.26 1.31 0.90 352.60
24 0.73 1.59 19.64 22.23 1.29 0.88 352.58
25 0.61 1.35 18.46 20.99 1.27 0.87 352.57
26 0.49 1.10 17.08 19.56 1.24 0.85 352.55
27 0.37 0.86 15.53 17.94 1.21 0.83 352.53
28 0.24 0.61 13.80 16.14 1.17 0.82 352.52
29 0.12 0.37 11.92 14.17 1.13 0.80 352.50
30 0.00 0.12 9.97 12.04 1.04 0.76 352.46
31 0.00 0 00 8.07 9.97 0.95 0.72 352.42
32 0.00 0.00 6.33 8.07 0.87 0.68 352.38
33 0.00 0.00 4.74 6.33 0.79 0.66 352.36
34 0.00 0.00 3.29 4.74 0.73 0.63 352.33
35 0.00 0.00 2.03 3.29 0.63 0.54 352.24
36 0.00 0.00 1.13 2.03 0.45 0.45 352.15
37 0.00 0.00 0.50 1.13 0 32 0.37 352.07
38 0.00 0 00 0.06 0.50 0 22 0.32 352 .02
39 0.00 0 00 0.01 0.06 0.03 0.11 351 .81
40 0.00 0 00 0.00 0.01 0 00 0 00 351 .70
pond 1-8in-pipe-rev xis
Northgate Lofts
Storage Routing Analysis
Pond 1 -Revised
100-Year Storm Event
Time Inflow 11+12 Outflow
(min.) (cfs) (cfs) 2s/t-0 2s/t+O (cfs) Depth (ft.) Elevation
0 0.00 0.00 0.00 0.00 0.00 0.00 351 .70
1 0.26 0.26 0.03 0.26 0.11 0.21 35 1.91
2 0.51 0 77 0.26 0.80 0.27 0.34 352.04
3 0.77 1.28 0.78 1.54 0.38 0.42 352.12
4 1.02 1.79 1.52 2.58 0.53 0.49 352.19
5 1.28 2.30 2.45 3.83 0.69 0.58 352.28
6 1.54 2.82 3.77 5.27 0.75 0.65 352.35
7 1.79 3.33 5.44 7.10 0.83 0.66 352.36
8 2.05 3.84 7.44 9.28 0.92 0.71 352.41
9 2.30 4.35 9.74 11 .80 1.03 0.75 352.45
10 2.56 4.86 12.33 14.61 1.14 0.81 352.51
11 2.43 4.99 14.94 17.32 1.19 0.83 352.53
12 2.30 4.74 17.19 19.67 1.24 0.85 352.55
13 2.18 4.48 19.11 21 .67 1.28 0.87 352.57
14 2.05 4.22 20.70 23.33 1.32 0.91 352.61
15 1.92 3.97 21 .99 24.67 1.34 0.92 352.62
16 1.79 3.71 22 .97 25.70 1.36 0.93 352.63
17 1.66 3.46 23.67 26.43 1.38 0.94 352.64
18 1.54 3.20 24.10 26.87 1.39 0.95 352.65
19 1.41 2.94 24.26 27 04 1.39 0 95 352.65
20 1.28 2.69 24 .17 26.95 1.39 0.95 352.65
21 1.15 2.43 23 .84 26.60 1.38 0.94 352.64
22 1 02 2.18 23 .28 26.02 1.37 0.93 352.63
23 0.90 1.92 22.49 25.20 1.35 0.92 352.62
24 0.77 1.66 21.49 24.16 1.33 0.91 352.61
25 0.64 1.41 20.29 22.90 1.31 0.90 352.60
26 0.51 1.15 18.89 21 .44 1.28 0.87 352.57
27 0.38 0.90 17.30 19.78 1.24 0.85 352.55
28 0.26 0.64 15.53 17.94 1.21 0.83 352.53
29 0.13 0.38 13.58 15.91 1.16 0.82 352.52
30 0.00 0.13 11.49 13.71 1.11 0.79 352.49
31 0.00 0 00 9.47 11.49 1.01 0.73 352.43
32 0.00 0.00 7.61 9.47 0.93 0.72 352.42
33 0.00 0 00 5.91 7.61 0.85 0.67 352.37
34 0.00 0.00 4.36 5.91 0.78 0.66 352.36
35 0.00 0 00 2.94 4.36 0.71 0.60 352.30
36 0.00 0 00 1.78 2.94 0.58 0.53 352 .23
37 0 00 0 00 0.96 1.78 0.41 0.43 352 .13
38 0.00 0 00 0.37 0.96 0.29 0.36 352.06
39 0.00 0.00 0.04 0.37 0.16 0.26 351 .96
40 0.00 0.00 0 00 0 04 0 02 0 10 351 80
41 0.00 0.00 0.00 0.00 0 00 0.00 351.70
42 0.00 0.00 0.00 0.00 0 00 0 00 351.70
43 0.00 0.00 0.00 0.00 0.00 0 00 351 . 70
44 0.00 0 00 0.00 0.00 0 00 0.00 351 .70
45 0.00 0 00 0.00 0.00 0.00 0.00 351 .70
pond 1-8 in -pipe-rev xis
EXHIBIT A
Pre-Development Drainage Area Map
18
EXHIBIT B
Post-Development Drainage Area Map
20