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Home My WebLink AboutDrainage ReportDRAINAGE REPORT FOR INDIAN LAKES SUBDIVISION PHASE 17 September 2013 PREPARED FOR: SMILING MALLARD DEVELOPMENT, LTD. 3608 EAST 29TH STREET BRYAN, TEXAS 77802 0"MISl.' 1011! MBESI No.10620039 rMMcCLURE & BROWNE ENGINEERING/SURVEYING, INC. 1008Woodcreek Dr., Suite 103 College Station, Tx. 77845 (979)693-3838 Engineer Reg. No. F-458 1314 10th Street, Suite 210 Huntsville, Tx. 77320.(936) 294-9749 Survey Reg. No. 101033-00 Indian Lakes Subdivision, Phase 17 Stormwater Management Technical Design Summary Report MBESI No. 10620037 PART 1— Executive Summary Report Section 1— Contact Information Project Designer: McClure and Browne Engineering and Surveying, Inc. 1008 Woodcreek Drive, Suite 103 College Station, TX 77845 979-693-3838 Project Developer: Smiling Mallard Development, Ltd. 3608 East 29111 Street Bryan, Texas 77802 Section 2 — General Information and Project Location This development is the 17' phase of a multi phase subdivision. Phase 17 consists of 19 lots. The phase is located in the Indian Lakes Village which is down Arrington Rd approximately 2 miles from the Arrington Rd. William D. Fitch Pkwy intersection. Phase 17 lies in the southeast portion of the subdivision near the intersection of Indian Lakes Dr and Matoska Ridge. The entire subdivision has been analyzed in the initial drainage report submitted in September, 2000. The development is entirely located within the city limits of College Station. The project site is in the Peach Creek watershed. According to the Flood Insurance Rate Maps for Brazos County, Texas and incorporated area, Map Number 48041CO350E effective May 16, 2012; no portion of this property is located in a 100-year flood hazard area. Culvert pipe and ditch sizing calculations are shown with this submittal. The culverts and ditches peak runoffs were found using the Rational Method. 0.50 was used for residential areas since all the lots have an area greater than the proposed roadways are uniform throughout the project. The ditch pi roadways were determined using the largest ditch drainage area found for P] ditches were analyzed using Hydraflow Express Extension for AutoCAD Cii Manning's Equation for the analysis. Section 3 — Reference Exhibit A Vicinity Map Exhibit B Excerpt from FEMA FIRM & BCS Watershed Map Exhibit C Culvert Pipe & Ditch Calculations Exhibit D Drainage Area Map Exhibit E Technical Design Summary Drainage Report Indian Lakes, Phase 17 A runoff coefficient (c) of 1 acre. The ditches along ofiles along all proposed Lase 17. The culverts and it 3D 2012 which utilizes EXHIBIT A Vicinity Map Drainage Report Indian Lakes, Phase 17 Vicinity Map EXHIBIT "A" VICINITY MAP /ND/AN LAKES PHASE XIO/ COLLEGE STAT/ON, BRAZOS COUNTY, TEXAS EXHIBIT B FEMA FIRM Map & BCS Watershed Map Drainage Report Indian Lakes, Phase 17 SECTION IX APPENDIX B — REGION'S WATERSHEDS 14,MD 7,000 0 14,000FFeet"� ,y uAW ,(t "N1 B WATERSHED RASUI LAW ALUMCREEK 2 UEE ORIARCEK 1 r CREEK 4 BRUSITYC 4 BRUSHY CREEK ,+ 5 BURT011 CREEK 6 CARTERS CREEK j, 7 COTTOIIW000 BRAIICN 8 HUDSOIICREEK 9 LICK CREEK r` 16 LITTLE WICKSOD MEEK 11 PEACH CREEK 12 SPRIIIG CRE EK q 13 STEEP HOLLOW BRPJICHri> sW,480' 14 STILL CREEK 13 TX OhP50115BRA11CH .> 16 THOdP50115 CREEK tt WHITEY CREEK J 18 WHITES CREEK 19 WACKSOU CREEK A-- 28 WiOI.FPEHCREEK a`x S+ Figure B-1: Watersheds of Bryan / College Station Region STORMWATER DESIGN GUIDELINES Page 4 of 24 APPENDIX B: REGION'S WATERSHEDS Effective February 2007 As Revised August 2012 SECTION IX Feet 0 4050 8,100 16200 Figure B-12: Peach Creek Watershed Area STORMWATER DESIGN GUIDELINES Page 15 of 24 APPENDIX B: REGION'S WATERSHEDS Effective February 2007 As Revised August 2012 EXHIBIT C Culvert Pipe & Ditch Calculations Drainage Report _ Indian Lakes, Phase 17 N G O R 3 c� m (.i d L T Q V d T w X 0 Q S w a R 3 E O LL R 0 O m K O OQM h O m m m 0I OOLI=NNN_O O O h h C � mom m OSD N ��6ocir m D N OSI ? e N A to m ST.D N V m N U — N m O O O O SZI = m of m of CO of P r c oN -nm 060 `O a"O fO m m m LL� Q`I S m m m m C n v m Samor m n n n m S1=�rry e zaNm�� N U mm mm 7.1 = m fD m [O m [O (D V _C O O O �- �13sn�000m �ma�q7 LLJ N � N ,U100I3A�"""`- IIVd o000 m N MOId a311n0 0 0 0 0 HlON31 MO -Id y311nEJ o IIVd o 0 0 0 MOId ONVIU3AO m O N N N 0000 HlON3l MOIJ ONVIN3AO tl01tl101 P � ni m mo v e�0000 IN3W3AVd m o o 0 0 0 0 0 0 bI IVI1N301SEINc'Norv0tl321tl ao03dO13A30Nn�nNV3ZIV IV1O1 VmVMIV 30VNInQ Zv J S W 0 n a � � o d N j U U MN� NN(i A r;a >L ws� 0 0 n a N N > i — O U s ( w c 0 n a U m ro 0 0 U x ( w M 0 n a U m K C � N C N > > > U 0 Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2012 by Autodesk, Inc. -_ Control Ditch 25-yr Triangular Side Slopes (z:1) = 4.00, 4.00 Total Depth (ft) = 2.00 Invert Elev (ft) = 249.00 Slope (%) = 1.00 N-Value = 0.030 Calculations Compute by: Known Q Known Q (cfs) = 11.70 -- Elev (ft) Section 252.00 Wednesday, Feb 20 2013 Highlighted Depth (ft) = 0.99 Q (cfs) = 11.70 Area (sqft) = 3.92 Velocity (ft/s) = 2.98 Wetted Perim (ft) = 8.16 Crit Depth, Yc (ft) = 0.89 Top Width (ft) = 7.92 EGL (ft) = 1.13 Depth (ft) 3.00 251.50 2.50 251.00 ^-- _--- - -- ----- - -- 2.00 250.50 — --- — ----- -- -- - 1.50 _ 250.00 1.00 249.50 — -- '- —__ 0.50 249.00 0.00 248.50 0 2 4 6 8 10 12 14 16 0.50 18 20 Reach (ft) Channel Report Hydreflow Express Extension for AutoCAD® Civil 3D® 2012 by Autodesk, Inc. Control Ditch 100-yr -' Triangular Side Slopes (zA) = 4.00, 4.00 Total Depth (ft) = 2.00 Invert Elev (ft) = 249.00 Slope (%) = 0.85 N-Value = 0.030 Calculations Compute by: Known Q Known Q (cfs) = 13.80 Elev (ft) 252.00 - 251.50 - 251.00 250.50 250.00 249.50 249.00 248.50 Section Wednesday, Feb 20 2013 Highlighted Depth (ft) = 1.08 Q (cfs) = 13.80 Area (sqft) = 4.67 Velocity (ft/s) = 2.96 Wetted Perim (ft) = 8.91 Crit Depth, Yc (ft) = 0.95 Top Width (ft) = 8.64 EGL (ft) = 1.22 2 4 6 8 10 12 14 16 18 20 Reach (ft) Depth (ft) 3.00 2.50 2.00 1.50 1.00 L tt n An W mm IS 5"E FW o LL c m a W W O c T m d �c�i ov5m3 3 W sa wc? 9 0 d Q E m Z o Qm Q� m 8 �ffiv;m o W F zA3= m.00 xam immm� - o Z qEa° o o EEu. W N y rA Op ? �V0U _ jE9E tea$ o.mci Q s`°ap4 fe zJ tau Nq O W E mwo _ �z iv 0.2E C F 0 C y o �a� '6icmc o.ID q '� `oiE `o Q d"m In zoo. [i dlicq 9 ° E a 0 a ® a e 4 a ®®® 7 ® 7 m�. �° .Me M e O mm0 -{- U-c a �.1.0 DRIVE CHEROKE LLJ Aid— , U „o LU ,r y Z DR�JE Q .. SJ�":: ?: O�,SglbuS4 VOh �� V� `.V.iV j y Z w... C U] n N C a SO A ¢I s u� Ua C 4' N W ci ti d e E M1 ��I�� o y w ID � h m - NIaVJ YV `l'� OE GPV G9 DR z o L vil c � + a in, 4z w -z: �o o w h LL F� LL rjv I'' o Sti NN o 0 Z O N O y C y O 0 O p UY � F C~iY U� Q �� EXHIBIT D Drainage Area Map Drainage Report Indian Lakes, Phase 17 EXHIBIT E Technical Design Summary Drainage Report Indian Lakes, Phase 17 • W. ►■ ■► Mfflyj11 4 The Cities of Bryan and College Station both require storm drainage design to follow these Unified Stormwater Design Guidelines. Paragraph C2 of Section III (Administration) requires submittal of a drainage report in support of the drainage plan (stormwater management plan) proposed in connection with land development projects, both site projects and subdivisions. That report may be submitted as a traditional prose report, complete with applicable maps, graphs, tables and drawings, or it may take the form of a "Technical Design Summary". The format and content for such a summary report shall be in substantial conformance with the description in this Appendix to those Guidelines. In either format the report must answer the questions (affirmative or negative) and provide, at minimum, the information prescribed in the "Technical Design Summary" in this Appendix. The Stormwater Management Technical Design Summary Report shall include several parts as listed below. The information called for in each part must be provided as applicable. In addition to the requirements for the Executive Summary, this Appendix includes several pages detailing the requirements for a Technical Design Summary Report as forms to be completed. These are provided so that they may be copied and completed or scanned and digitized. In addition, electronic versions of the report forms may be obtained from the City. Requirements for the means (medium) of submittal are the same as for a conventional report as detailed in Section III of these Guidelines. Note: Part 1 Executive Summary must accompany any drainage report required to be provided in connection with any land development project, regardless of the format chosen for said report. Note: Parts 2 through 6 are to be provided via the forms provided in this Appendix. Brief statements should be included in the forms as requested, but additional information should be attached as necessary. Part 1 — Executive Summary Report Part 2 — Project Administration Part 3 — Project Characteristics Part 4 — Drainage Concept and Design Parameters Part 6 — Plans and Specifications Part 6 — Conclusions and Attestation STORMWATER MANAGEMENT TECHNICAL DESIGN SUMMARY REPORT Part 1 — Executive Summary This is to be a brief prose report that must address each of the seven areas listed below. Ideally it will include one or more paragraphs about each item. Name, address, and contact information of the engineer submitting the report, and of the land owner and developer (or applicant if not the owner or developer). The date of submittal should also be included. 2. Identification of the size and general nature of the proposed project, including any proposed project phases. This paragraph should also include reference to applications that are in process with either City: plat(s), site plans, zoning requests, STORMWATER DESIGN GUIDELINES Page 1 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY or clearing/grading permits, as well as reference to any application numbers or codes assigned by the City to such request. 3. The location of the project should be described. This should identify the Named Regulatory Watershed(s) in which it is located, how the entire project area is situated therein, whether the property straddles a watershed or basin divide, the approximate acreage in each basin, and whether its position in the Watershed dictates use of detention design. The approximate proportion of the property in the city limits and within the ETJ is to be identified, including whether the property straddles city jurisdictional lines. If any portion of the property is in floodplains as described in Flood Insurance Rate Maps published by FEMA that should be disclosed. 4. The hydrologic characteristics of the property are to be described in broad terms: existing land cover; how and where stormwater drains to and from neighboring properties; ponds or wetland areas that tend to detain or store stormwater; existing creeks, channels, and swales crossing or serving the property; all existing drainage easements (or ROW) on the property, or on neighboring properties if they service runoff to or from the property. 5. The general plan for managing stormwater in the entire project area must be outlined to include the approximate size, and extent of use, of any of the following features: storm drains coupled with streets; detention / retention facilities; buried conveyance conduit independent of streets; swales or channels; bridges or culverts; outfalls to principal watercourses or their tributaries; and treatment(s) of existing watercourses. Also, any plans for reclaiming land within floodplain areas must be outlined. 6. Coordination and permitting of stormwater matters must be addressed. This is to include any specialized coordination that has occurred or is planned with other entities (local, state, or federal). This may include agencies such as Brazos County government, the Brazos River Authority, the Texas A&M University System, the Texas Department of Transportation, the Texas Commission for Environmental Quality, the US Army Corps of Engineers, the US Environmental Protection Agency, et al. Mention must be made of any permits, agreements, or understandings that pertain to the project. 7. Reference is to be made to the full drainage report (or the Technical Design Summary Report) which the executive summary represents. The principal elements of the main report (and its length), including any maps, drawings or construction documents, should be itemized. An example statement might be: "One -page drainage report dated , one set of construction drawings (_sheets) dated and a -page specifications document dated comprise the drainage report for this project." STORMWATER DESIGN GUIDELINES Page 2 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 — Project Administration Start (Page 2.1) Engineering and Design Professionak Information Engineering Firm Name and Address: Jurisdiction McClure & Browne Engineering/Surveying, Inc. City: Bryan 1008 Woodcreek Drive, Suite 103 X College Station College Station, Texas 77845 Date of Submittal: (979)693-3836 Lead Engineer's Name and Contact Info.(phone, e-mail, fax): Other: Jeffery L. Robertson, P.E. Supporting Engineering / Consulting Firm (s): Other contacts: Developer Iwner / A" " licant Information Developer / Applicant Name and Address: Phone and e-mail: Smiling Mallard Development, Ltd. (979) 846-4384 3608 East 29th Street Bryan, Texas 77802 Property Owner(s) if not Developer / Applicant (& address): Phone and e-mail: Project Identification Development Name: Indian Lakes, Phase 12 Is subject property a site project, a single-phase subdivision, or part of a multi -phase subdivision? Multi -phase Subdivision If multi -phase, subject property is phase 17 of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) Indian Lakes, Phase 17 If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. The project is the 17th phase of a multi phase subdivision. At this time the first phase h been built. Phase 1 was submitted in September, 2000 and consisted of 58 lots. The most recent phase submitted was Ph. 16. General Location of Project Area, or subject property (phase): Project site is located approximately 600 feet to the north of the intersection of Indian Lakes Drive and Matoska Ridge in College Station, Texas. In City Limits? Extraterritorial Jurisdiction (acreage): Bryan: acres. Bryan: College Station: College Station: 36.357 acres. Acreage Outside ETJ: STORMWATER DESIGN GUIDELINES Page 3 of26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 — Project Administration Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or subject property: Indian Lakes Drive Abutting tracts, platted land, or built developments: Indian Lakes, Phase 12 Named Regulatory Watercourse(s) & Watershed(s): Phase 17 is located in the Peach Creek Watershed. Tributary Basin(s): The nearest tributary is Peach Creek S. Tributary 7.2 (See FEMA Map 48O41C0350E). Plat Information For Project or Subject Property (or Phase) Preliminary Plat File #: (dame: Pending Approval Final Plat File #: Date: Status and Vol/Pg: Pending Approval If two plats, second name: File #: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: PD-a (224.53 ac.) Existing or Proposed? Existing Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: Preliminary Report Required? Submittal Date Review Date Review Comments Addressed? Yes _ No _ In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. STORMWATER DESIGN GUIDELINES Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 - Project Administration Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Dept. Contact: Date: Subject: Coordination With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non jurisdiction City Needed? Yes No x Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No x Summarize need(s) & actions taken (include contacts & dates): Coordination with TxDOT Needed? Yes No X Coordination with Summarize need(s) & actions taken (include contacts & dates): TAMUS Needed? Yes No x Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective ins aces below. EntityPermitted or Status of Actions (include dates) Approved ? US Army Crops of Engineers No x Yes _ US Environmental Protection Agency No x Yes Texas Commission on A Stormwater Pollution Prevention Plan must be Environmental Quality implemented prior to the start of construction No _ Yes x according to TPDES General Permit No. TXR150000. Brazos River Authority No X Yes STORMWATER DESIGN GUIDELINES Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? Existing undeveloped land (Dense tree cover). Existing impervious cover is approximately 0 sf. Site — Redevelooment of one platted lot, or two or more adjoining platted lots. Development Building on a single platted lot of undeveloped land. Project — Building on two or more platted adjoining lots of undeveloped land. (select all applicable) — Building on a single lot, or adjoining lots, where proposed plat will not form a new street (but may include ROW dedication to existing streets). _ Other (explain): Subdivision x Construction of streets and utilities to serve one or more platted lots. Development Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site proiects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. $12e Of This phase of the subdivision includes 19 lots. The development Proposed consists of approximately 3,500 LF of streets with 16' PIIE on each Project side of the streets ROW. Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? x No Yes FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse No x Yes (Section II, Paragraph B1) or a tributary thereof? Is any part of subject property in floodplain No x Yes Rate Map 48041CO350E area of a FEMA-regulated watercourse? Encroachment(s) into Floodplain Encroachment purpose(s): Building site(s) Road crossing(s) areas planned? Utility crossing(s) Other (explain): No x Yes If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. STORMWATER DESIGN GUIDELINES Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Yes Reference the study (& date) here, and attach copy if not already in City files. x Indian Lakes Subdivision; September, 2000 Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes x No If not, explain how it differs. No If subject property is not part of multi -phase project, describe stormwater management plan for the property in Part 4. If property is part of multi -phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? x No Yes Describe them (include approximate size, volume, outfall, model, etc). Any known drainage or flooding problems in areas near subject property? x No Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) Detention is required. x Need must be evaluated. Detention not required. What decision has been reached? By whom? Detention study during Phase 1. If the need for How was determination made? Type Detention Detention was required and is provided for the entire must be evaluated: Indian Lakes Subdivision. However, Phases 17 does not require any additional detention. STORMWATER DESIGN GUIDELINES Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? x No Yes If yes, describesplits below. In Part 4 describe design conce t for handling this. Watershed or Basin Lar er acrea a Lesser acreage Above -Project Areas(Section II, Paragraph B3-a) Does Project Area (project or phase) receive runoff from upland areas? _ No X Yes Size(s) of area(s) in acres: 1) 2.7 Ac. 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non -regulatory), regulatory Watercourse or tributary); Phase 17 receives overland sheet from the east from the existing gas line easement. Flow determination: Outline hydrologic methods and assumptions: The Rational Method was used for flow calculations and the post development land was treated as large acre residential tracts. Does storm runoff drain from public easements or ROW onto or across subject property? x No Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain No upstream land is already developed. Conveyance Pathways (Section II, Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? No x Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). Runoff from Ph. 17 will leave the phase and be discharged into existing tributaries of Peach Creek. The property is a future phase of the Indian Lakes Subdivision, STORMWATER DESIGN GUIDELINES Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 3 — Propertv Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage If yes, for what part of length? % Created by?_ plat, or easements instrument. If instrument(s), describe their provisions. exist for any part of pathway(s)? x No Yes Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Pathway Areas Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Nearby Drainage Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? x No Yes If yes, explain: STORMWATER DESIGN GUIDELINES Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? x No _Yes Separate Instrument? X No Yes Per Guidelines reference above, how will Establishing Easements (Scenario 1) runoff be discharged to neighboring Pre -development Release (Scenario 2) property(ies)? Combination of the two Scenarios Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit #� Scenario 2: Provide general description of how release(s) will be managed to pre -development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit #_) Combination: If combination is proposed, explain how discharge will differ from pre - development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? No Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Page 10 of26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi -Phase Project Identify gaining Basins or Watersheds and acres shifting: Will project result in shifting runoff between Basins or between What design and mitigation is used to compensate for increased runoff Watersheds? from gaining basin or watershed? x No Yes How will runoff from Project 1. With facility(ies) involving other development projects. Area be mitigated to pre - development conditions? 2 — Establishing features to serve overall Project Area. Select any or all of 1, 2, 3. x On phase (or site) project basis within Project Area. and/or 3, and explain below. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit #� 2. For Overall Proiect Area (type & location of facilities): (Attached Exhibit #) 3. By phase (or site) oroiect: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? _ No _ Yes In which phase(s) or project(s)? r r Are other Best Management Practices for reducing stormwater pollutants proposed? o _ No Yes Summarize type of BMP and extent of use: c I a� N a) o 0 Z If design of any runoff -handling facilities deviate from provisions of B-CS Technical x Specifications, check type facility(ies) and explain in later questions. Go 0 Detention elements Conduit elements _ Channel features Swales Ditches— Inlets _ Valley gutters _ Outfalls Culvert features Bridges Other STORMWATER DESIGN GUIDELINES Page 11 of26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Proiect Area Of Multi -Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? _ No x Yes Identify type and general size and In which phase(s). Culvert #1 - 24" RCP Pipe on Kiowa Cove Culvert #2 - 24" RCP Pipe on Kiowa Cove Culvert #3 - 1811 RCP Pipe B Sagamore Court and Kiowa Cove Culvert #4 - 2-24" RCP Pipe Q Iroquois Cove and Sagamore Court If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyance pathway(s), construction sequence): Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? —Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? Surfaces? c� V-Shape Grass Steepest side slopes: Usual front slopes: Usual back slopes: m 4:1 4:1 4:1 N x Flow line slopes: least ° 70 ^ Typical distance from travelway: ii a varies 6.50% typical greatest (Attached Exhibit#� a O N Z Ca ° Are longitudinal culvert ends in compliance with B-CS Standard Specifications? x Yes No, then explain: y At intersections or otherwise, do valley gutters cross arterial or collector streets? 9 Q No Yes If yes explain: oa yAre valley gutters proposed to cross any street away from an intersection? = o �z _ No _ Yes Explain: (number of locations?) ya P x) STORMWATER DESIGN GUIDELINES Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? Yes If "no", _No identify where and why. Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? Yes _ No If no, explain where and why not. a N Will inlet size and placement prevent exceeding allowable water spread for 10-year a) design storm throughout site (or phase)? _ Yes No If no, explain. rn c� Sag curves: Are inlets placed at low points? Yes No Are inlets and conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? Yes No Explain "no" answers. N N N V! P Will 100-yr stormflow be contained in combination of ROW and buried conduit on whole length of all streets? Yes No If no, describe where and why. Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications? Yes No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? No Yes Identify length(s) and where used. 0 Ny Pipe runs between system Typical Longest access points (feet): r Are junction boxes used at each bend? _ Yes No If not, explain where > and why. o �z E xly Are downstream soffits at or below upstream soffits? Least amount that hydraulic N Yes No If not, explain where and why: grade line is below gutter line (system -wide): STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Describe watercourse(s), or system(s) receiving system discharge(s) below (include design discharge velocity, and angle between converging flow lines). U 1) Watercourse (or system), velocity, and angle? 0 Culverts discharge into Unnamed Tributary to Peach Creek Tributary. N velocity v< 10 fps O Angle in -line with existing defined channels. m E 2) Watercourse (or system), velocity, and angle? c `o 0 o U O N N E N 3) Watercourse (or system), velocity, and angle? y �a O L "a a E For each outfall above, what measures are taken to prevent erosion or scour of yreceiving and all facilities at juncture? N 1) Rock Rip Rap at discharge into defined channel. cc a 2) N 0 3) Are swale(s) situated along property lines between properties? No Yes Number of instances: For each instance answer the following questions. Surface treatments (including low -flow flumes if any): a N N } Flow line slopes (minimum and maximum): c -`0 0 a) o 3 z Outfall characteristics for each (velocity, convergent angle, & end treatment). CD 3 a Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in all instances? Yes No If "no" explain: STORMWATER DESIGN GUIDELINES Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? No X Yes If so, provide the following: L Is 25-year flow contained with 6 inches of freeboard throughout ? X Yes No _ Are top of banks separated from road shoulders 2 feet or more? X Yes No _ Are all ditch sections trapezoidal and at least 1.5 feet deep? _ Yes X No y For any "no" answers provide location(s) and explain: All Ditches are V-shaped and at least 2' deep 0 K If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: r Is 100-year design flow contained in conduit/swale combination? —Yes —No If "no" explain: a) 0 m Space for 100-year storm flow? ROW Easement Width z E Swale Surface type, minimum Conduit Type and size, minimum and maximum xland maximum slopes: slopes, design storm: 0 r' m Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): c �+ m � m t U � Access Describe how maintenance access is provided (to swale, into conduit): 0 .0 o Ca E Instance 2 Describe general location, approximate length: E m m � N Is 100-year design flow contained in conduit/swale combination? Yes No o _ _ If "no" explain: W a E a) Space for 100-year storm flow? ROW Easement _ Width o 0 Swale Surface type, minimum Conduit Type and size, minimum and maximum ii and maximum slopes: slopes, design storm: c m 0 N Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): m Q 3 0 N Access Describe how maintenance access is provided (to swale, into conduit): STORMWATER DESIGN GUIDELINES Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters I Continued (Page 4.7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) If "yes" provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: c n E w r j Is 100-year design flow contained in swale? Yes No Is swale wholly >- _ _ within drainage ROW? Yes No Explain "no" answers: _ Access Describe how maintenance access is provide: a) o Z 0 X O Instance 2 Describe general location, approximate length, surfacing: a� � c N o E L N 3 Is 100-year design flow contained in swale? —Yes —No Is swale wholly `o within drainage ROW? Yes No Explain "no" answers: _ w _ U of Access Describe how maintenance access is provided: U_ Z 3 a Instance 3, 4, etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? _ No Yes If only slightly shaped, see "Swales" in this Part. If creating side banks, provide information below. r Will design replicate natural channel? Yes No If "no", for each instance 0 o describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year o w design flow, and amount of freeboard: N Instance 1: c (D N i E E 'o Instance 2: n E o — Z X Instance 3: M U STORMWATER DESIGN GUIDELINES Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? No Yes If "yes" provide the information below. Will small creeks and their floodplains remain undisturbed? _ Yes _ No How many disturbance instances? Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. a c c oWatercourses (and tributaries): Aside from fringe changes, are Regulatory Watercourses proposed to be altered? No Yes Explain below. c Submit full report describing proposed changes to Regulatory Watercourses. Address E existing and proposed section size and shape, surfaces, alignment, flow line changes, length affected, and capacity, and provide full documentation of analysis procedures ° and data. Is full report submitted? Yes No If "no' explain: a E 75 c c All Proposed Channel Work: For all proposed channel work, provide information requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? —Yes —No If not, identify location and explain: Are ROW / easements sized to contain channel and required maintenance space? Yes _ No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.9) Stormwater Management Concept(continued) Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? For each provide info. below. For each dry -type facilitiy: Facility 1 Facility 2 Acres served & design volume + 10% 100-yr volume: free flow & plugged Design discharge (10 yr & 25 yr) Spillway crest at 100-yr WSE? yes _ no yes _ no Berms 6 inches above plugged WSE? yes _ no yes _ no Explain any "no" answers: N N } For each facility what is 25-yr design Q, and design of outlet structure? Facility 1: 0 zl Facility 2: X Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: —Yes —No Facility 2: —Yes —No If "no' explain: N O a O o For each, what is velocity of 25-yr design discharge at outlet? & at s ilo Iwav? Facility 1: & Facility 2: & 5 Are energy dissipation measures used? No Yes Describe type and co u- _ location: c 0 m m 0 For each, is spillway surface treatment other than concrete? Yes or no, and describe: 2 Facility 1: Facility 2: For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Facility 2: If berms are used give heights, slopes and surface treatments of sides. Facility 1: Facility 2: STORMWATER DESIGN GUIDELINES Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters I Continued (Page 4.10) Stormwater Management' Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": Facility 1; m Facility 2: c o C +� o C U oFor additional facilities provide all same information on a separate sheet. Are parking areas to be used for detention? No Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? _ No X Yes If "yes", provide information in next two boxes. Will 25-yr. flow pass without flowing over driveway in all cases? x Yes _ No Without causing flowing or standing water on public roadway? X Yes _ No Designs & materials comply with B-CS Technical Specifications? X Yes _ No Explain any "no" answers: N 01 C oAre culverts parallel to public roadway alignment? x Yes No Explain: u � X I a Creeks at Private Drives: Do private driveways, drives, or streets cross drainage m ways that serve Above -Project areas or are in public easements/ ROW? z No X Yes If "yes" provide information below. How many instances? 2 Describe location and provide information below. > Location 1: The 24" culverts crossing under Kiowa Cove will serve U approximately 2.7 acres from ex. Indian Lakes phases. Location 2: Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? loo loo Water depth on travelway at 25-year flow? 0 ^ 0 Water depth on travelway at 100-year flow? 0 ^ 0 For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.11) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulatory Watercourses (& Tributaries): Are culverts proposed on these facilities? X No Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? Yes —No If "no", explain: Arterial or Maior Collector Streets: Will culverts serve these types of roadways? X No Yes How many instances? For each identify the location and provide the information below. m Instance 1: r a ti Instance 2: x 0 Instance 3: c 0 0 Ca z Yes or No for the 100-year design flow: 1 2 3 E `o Headwater WSE 1 foot below lowest curb top? c E Spread of headwater within ROW or easement? Is velocity limited per conditions (Table C-11)? N C Explain any "no" answer(s): N O 0 J aS J 3 0 o .0 Minor Collector or Local Streets: Will culverts serve these types of streets? No X Yes How many instances? 4 for each identify the location and provide the information below: a.� Instance 4: 2-24" RCP on Irc 0 Instance 1: 24" RCP on Kiowa Cove. >, a) 24" RCP on Kiowa Cove. Instance 2: as 0 w `o Instance 3: 18" RCP @ Kiowa Cove and Sagamore Court w For each instance enter value, or "yes" / "no" for4 1 2 3 n N m � Design yr. headwater WSE 1 ft. below curb top? Yes Yes Yes 100-yr. max. depth at street crown 2 feet or less? Yes Yes Yes E Product of velocity (fps) & depth at crown (ft) = ? 0 0 0 Is velocity limited per conditions (Table C-11)? Yes Yes Yes Limit of down stream analysis (feet)? 10 10 10 Explain any "no" answers: STORMWATER DESIGN GUIDELINES Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 ruois Cove a Yes Yes 0 Yes 10 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? X Yes No If not, identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? X No _ Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? X No _Yes If yes, identify location(s) and provide justification: Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? X No _ Yes If "yes" identify location(s), describe outfall design treatment(s): c G O U y a' Is scour/erosion protection provided to ensure long term stability of culvert structural 0 components, and surfacing at culvert ends? X Yes —No If "no" Identify locations and provide justification(s): Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? X Yes _ No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? X No Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? X Yes _ No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Desian Parameters Continued (Page 4.13) Stormwater Management concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is abridge included in plans for subject property project? —No —Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? N N a o] A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? —Yes —No If "no" explain: Is a Stormwater Provide a general description of planned techniques: Pollution Prevention Silt fence and inlet filtration will serve as the ca d Plan (SW3P) established for main protection against stormwater B g pollution. The project construction? Contractor shall use any other means necessary throughout construction. No X Yes Special Designs — Non -Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland -type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? X No —Yes If "yes" list general type and location below. Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? _ Yes _ No If "no" explain: STORMWATER DESIGN GUIDELINES Page 22 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.14) Stormwater ManagementConcept (continued) , Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs — Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff -handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. _ Detention elements Drain system elements Channel features _ Culvert features _ Swales _ Ditches Inlets _Outfalls Valley gutters _ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology Is a map(s) showing all Design Drainage Areas provided? x Yes No Briefly summarize the range of applications made of the Rational Formula: For the Rational Formula we assumed residential areas had a runoff coefficient of o.s for large residential or estate lots. What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? 8 * 25 acres Location (or identifier): SD-4 2-24 11 RCP @ Iroquois STORMWATER DESIGN GUIDELINES Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? x No _ Yes In approximately what percent of Design Drainage Areas? As to intensity -duration -frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? x No _Yes If "yes" identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them 2, 5,10 , 25, so,100 25 Detention facilities: spillway crest and its outfall Detention facilities: outlet and conveyance structure(s) Detention facilities: volume when outlet plugged Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities, 25 year Gutters Conduit Culverts Swales Channels Highest (feet per second) 8.25 Lowest (feet per second) 3.21 Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: NA For conduit type(s) RCP 0.013 HDPE 0.013 Coefficients: STORMWATER DESIGN GUIDELINES Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY --- Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? —No —Yes Head and friction losses _ No _ Yes Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? _ Yes _ No Are elevation drops provided at inlets, manholes, and junction boxes? —Yes —No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? _ Yes _ No For 100-year flow conditions? —Yes _No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Open Channels If a HEC analysis is utilized, does it follow Sec VI.F.5.a? _ Yes _ No Outside of straight sections, is flow regime within limits of sub -critical flow? X Yes _ No If `no" list locations and explain: Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? All culverts will be inlet controlled. Entrance, friction and exit losses: A 0.5 entrance and exit loss coefficients are used for sloped end treatments and square edged headwalls with wingwalls. Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY - Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher Open Office Calculator Spreadsheet Hydraflow Express Extension for AutoCAD Civil 3D 2012 Part 5 — Plans and Specifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section III, Paragraph C3. Part 6 — Conclusions and Attestation Conclusions Add any concluding information here: The Indian Lakes Subdivision, Phase 17 will have no adverse impact to downstream properties and conforms to the overall subdivision report. Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Design Summary Drainage Report by signing and sealing below. .This report (plan) for the drainage design of the development named in Part 8 was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements hav been issued or fall under applicable general permits." i (Affix Seal) Licens Profes " nal Engineer r E° tn State of Texas PE No. STORMWATER DESIGN GUIDELINES Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009