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HomeMy WebLinkAboutDrainage LetterApril 6, 2009 City of College Station Planning & Development Services 1101 Texas Avenue South College, Station, 77840 Sleep Inn & Suites -College Station, TX Utility Analysis Letter April 6, 2009 RE: Sleep Inn & Suites -1195 Earl Rudder Freeway South, College Station, TX Lot 2B, Block One -High Ridge Subdivision -Brazos County Drainage Letter RME No. 231-0351 To Whom It May Concern: The proposed addition referenced above consists of approximately 1.20 acres of increased impervious area which will consist of a hotel building, associated parking, and sidewalks. Using the Rational Method and the following parameters, an increase in runoff of approximately 8.37 cfs during the 100-year rainfall event would be experienced. Ration Method: Q = CIA CEXIST = 0.35 CNEW = 0.95 I = 11.63 in/hr Tc = 10 min. A = 1.20 acres Since this site is located directly adjacent to the primary drainage system of Carters Creek, via the drainage channel located adjacent and to the northeast of the project site, rapid conveyance of stormwater through and to the primary system is recommended. Therefore no detention facility is anticipated for this development. Please call should you have any questions or require assistance regarding this matter. Sincerely, April 6, 2009 City of College Station Planning & Development Services 1101 Texas Avenue South College, Station, 77840 Sleep Inn & Suites -College Station, TX Utility Analysis Letter April 6, 2009 RE: Sleep Inn & Suites -1195 Earl Rudder Freeway South, College Station, TX Lot 2B, Block One -High Ridge Subdivision -Brazos County Drainage Letter RME No. 231-0351 To Whom It May Concern: The proposed addition referenced above consists of approximately 1.20 acres of increased impervious area which will consist of a hotel building, associated parking, and sidewalks. Using the Rational Method and the following parameters, an increase in runoff of approximately 8.37 cfs during the 100-year rainfall event would be experienced. Ration Method: Q = CIA CEXJST = 0.35 CNEw = 0.95 I= 11.63 in/hr Tc= 10 min. A = 1.20 acres Since this site is located directly adjacent to the primary drainage system of Carters Creek, via the drainage channel located adjacent and to the northeast of the project site, rapid conveyance of stormwater through and to the primary system is recommended. Therefore no detention facility is anticipated for this development. Please call should you have any questions or require assistance regarding this matter. Sincerely, SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Engineering Firm Name and Address: Jurisdiction 'RM~ Lo~\Jt..""flt..I~ ~..s~$ City: Bryan ~Lr4!1>st~ Y.o. 12::cx '12S~ / College Station Cou..e..tJiz:. 5-rff11<i"'1, -r)(. 7~'{2.. Date of Submittal: ) J ..q lo \')., Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: t2:/.\e::oN ~ • n1 E-"'"({. lh .. ~ I r ,fl: .. {'11°> -Col b-t>~) Supporting Engineering I Consulting Firm(s): Other contacts: Develooer I Owner I Applicant lnfonnation Developer I Applicant Name and Address: Phone and e-mail: A~~ ""Cb~' Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: Project Identification Development Name: SL-€-~ INN~ ~t-rtz_.2::. Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? ~ If multi-phase, subject property is phase \ of "2-. Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) ~ ~-r 2..t=> I ?-:Lo c.'C.. Ot-JE..-~\~ G::rE:-~f:,C>Ntbl.~,..J 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. General Location of Project Area, or subject property (phase): -=>t\ Cs; -E-r «-~~ \=N\.~<i-~3a In City Limits? Extraterritorial Jurisdiction (acreage): Bryan: acres. Bryan: College Station: College Station: '2-1'2-°t acres. Acreage Outside ET J: Part 2 -Project Administration I Continued (page 2.2) Project Identification (continued) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 3 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: St-\ ~ -£.\-'L Nt~F/lt-S }c~t.P"f F(..)e 1 N-r~fZ... Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): c:: f'r(l.-c~ s ~ c~,~ ~ Plat Information For Project or Subject Property (or Phase) Preliminary Plat File #: Final Plat File#: Date: Name: Status and Vol/Pg: 7~\t:>) l€)'7 If two plats, second name: File#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: C.-1 Existing or Proposed? 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. Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: St-\ lo -E-P'L N11'iF/'rS >o-t!t..P1 F~e LNL'~fZ... Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): c::: fril-1. '¢>i. s ~ C~-r:?>lb -~ Plat Information For Project or Subject Property (or Phase) Preliminary Plat File#: Final Plat File#: Date: Name: Status and Vol/Pg: 7~\(:)} lE)i( If two plats, second name: File#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: C.-1 Existing or Proposed? 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. Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coordination Dept. Contact: Date: Subject: 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 __ Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? No/ Yes -- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No ,/ ---- Coordination with Summarize need(s) & actions taken (include contacts & dates): T AMUS Needed? Yes --No _L 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 in spaces below. Entity Permitted or Status of Actions (include dates) Aooroved? US Army Crops of Engineers No V Yes - US Environmental Protection Agency No V"' Yes - Texas Commission on Environmental Qu~ ~~(¥~ tJ'-oJ_ No __ Yes __ Brazos River Authority No /Yes - Part 3 -Pro perty Characteristics I Start (Page 3.1) Nature and Scope of Prop osed Wo rk STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Existing: Land proposed for development currently used, including extent of impervious cover? Site __ Redevelopment of one platted lot, or two or more adjoining platted lots. Development _!L'Building on a single platted lot of undeveloped land. Project __ Building on two or more platted adjoining lots of undeveloped land. (select all __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street {but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ 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 projects: 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. ~~ ~...s~ + ~\O"FCWA'-~ Size of t\tSCeL, '\)f3-f'e\.O fl'\/\\0"1 Pro~osed Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? _L_No --Yes FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse I No v Yes __ (Section II, Paragraph B 1) or a tributary thereof? Is any part of subject property in floodplain I No V Yes Rate Map area of a FEMA-regulated watercourse? -- Encroachment(s) Encroachment purpose(s): __ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No v -- 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. Part 3 -Property Characteristics I Continued {Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Existing: Land proposed for development currently used, including extent of impervious cover? Site __ Redevelopment 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 __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ 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 12ending 12lats. Site projects: 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. ~ ~ ~t-S Gi;-+ b\O"R-WA<.."-& Size of t\?S!E-L.. VP.Af?--\...v E'l'V'..o-i Pro~osed Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? _LNo --Yes FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse ., No V Yes __ (Section II, Paragraph 81) or a tributary thereof? Is any part of subject property in floodplain [No V Yes __ Rate Map area of a FEMA-regulated watercourse? Encroachment(s) Encroachment purpose(s): __ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No v -- 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. Part 3 -Property Characteristics I Continued (Page 3.2) Hydrologic.Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Yes Reference the study (&date) here, and attach copy if not already in City files. -- Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes 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? ~ No --Yes Describe them (include approximate size, volume, outfall, model, etc). / Yes Any known drainage or flooding problems in areas near subject property? _L._ No --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. Need must be evaluated. /Detention not required. -- What decision has been reached? By whom? If the need for Type 1 Detention How was determination made? must be evaluated: Part 3 -Proeertll Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or P~se) (continued) Does subject property straddle a Watershed or Basin divide? v No Yes If yes, --describe splits below. In Part 4 describe desiQn concept for handlinQ this. Watershed or Basin STORMWATER DESIGN GUIDELINES Effective February 2007 I I Page 7 of 26 Larger acreage I Lesser acreage I APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Above-Project Areas(Section II, Paragraph 83-a} Does Project Area (project or phase} receive runoff from upland areas? __ No VYes Size(s} of area(s} in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non-regulatory}, regulatory Watercourse or tributary}; C.sNc~~ ~ Oc:> I 1<.c.-P Flow determination: Outline hydrologic methods and assumptions: ~POl ~c..r~~\..,c.. ~Pr- Does storm ru~drain from public easements or ROW onto or across subject property? __ No __ Yes If yes, describe facilities in easement or ROW: 'Do \( ~p ~~ f;rO.Lucn~ Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section II, Paragraph C2} Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? v No Yes Describe length and characteristics of each conveyance pathway(s}. Include ownership of property(ies). Part 3 -Property Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage easements exist for any part of If yes, for what part of length? % Created by? __ plat, or __ instrument. If instrument(s}, describe their provisions. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Above-Project Areas(Section II, Paragraph 83-a) Does Project Area (project or phase) receive runoff from upland areas? __ No VYes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non-regulatory), regulatory Watercourse or tributary); C.sNc~~ ~ ~l 1<.L-f Flow determination: Outline hydrologic methods and assumptions: ~\::><3'{ ~y~~\..\C.. ~A- Does storm ru~drain from public easements or ROW onto or across subject property? __ No __ Yes If yes, describe facilities in easement or ROW: 'Do l( ~p ~~ ~o-r.~ Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section II, Paragraph C2) Must runoff from study property drairi across lower properties before reaching a Regulatory Watercourse or tributary? v No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). Part 3 -Pro(!ert:t 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 STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Pathway --P~N~ Gtlft"roJNU.... lN ~v-.l~ Areas Nearby Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Drainage 1----~~~~~--,--~~~~~~~~~~~~~~~~~~~~~~~~~ Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? __ No ~Yes If yes, explain: Part 4 -Drainage Conce~t and Design Parameters I 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. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Nr-~ '-'"V\ ~-e.::rr Cc~ 8::-C ~N w( 'lx'PC-C ~~{~~ Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project ~de drainage features (existing or future) proposed to become public via platting? __ No __ Yes Separate Instrument? 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. Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Will project result Identify gaining Basins or Watersheds and acres shifting: in shifting runoff between Basins or between STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY N €.~ '-'""V\ .,e.rJ.n C.c::.~ E...c ::-1. ~N w { ---r 'K \:)()( ~\ .. r.-(~~ Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project ~de drainage features (existing or future) proposed to become public via platting? __ No __ Yes Separate Instrument? No Yes Per Guidelines reference above, how will __ Establishing Easements (Scenario 1) runoff be discharged to neighboring property(ies )? __ Pre-development Release (Scenario 2) 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. Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Will project result Identify gaining Basins or Watersheds and acres shifting: in shifting runoff between Basins or between STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Watersheds? /No __ Yes What design and mitigation is used to compensate for increased runoff from gaining basin or watershed? How will runoff from Project Area be mitigated to pre- development conditions? Select any or all of 1, 2, and/or 3, and explain below. 1. __ With facility(ies) involving other development projects. 2. __ Establishing features to serve overall Project Area. 3. __ On phase (or site) project basis within Project Area. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facilities): (Attached Exhibit # ) 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? __ No project(s)? __ Yes In which phase(s) or Are other Best Management Practices for reducing stormwater pollutants proposed? __ No __ Yes Summarize type of BMP and extent of use: I If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. __ Detention elements __ Conduit elements __ Channel features __ Swales __ Ditches __ Inlets __ Valley gutters __ Outfalls __ Culvert features __ Bridges ________ Other Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? __ No V Yes Identify type and general size and In which phase(s). STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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? I Surfaces? C'-· "O Q) fl) Steepest side slopes: I Usual front slopes: I Usual back slopes: fl) ::J Q) fl) >- Q) I .i:; Flow line slopes: least Typical distance from travelway: .B :a typical (Attached Exhibit# ) Q) greatest F1 Are longitudinal culvert ends in compliance with B-CS Standard Specifications? ..... Yes No, then explain: <( fl) At intersections or otherwise, do valley gutters cross arterial or collector streets? ..0 Q) No Yes If yes explain: :; ('-. >---u "O I .i:; Q) .... fl) .§ ~ Are valley gutters proposed to cross any street away from an intersection? fl) Q) -~ Q) ::J 0 No Yes Explain: (number of locations?) ~ e>Z ----]~\1 Part 4 -Drainage ConceE!t and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) ~ Q; Gutter line slopes: Least Usual Greatest ::J ~('-. Are inlets recessed on arterial and collector streets? Yes No If "no", u ::J "O ----~ C) Q) "O fl) identify where and why. :;: c ::J ro STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 confonnance 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? I Surfaces? C'· "'O Q) (/) Steepest side slopes: I Usual front slopes: I Usual back slopes: (/) ::I Q) (/) >- Q) I ..c:. Flow line slopes: least Typical distance from travelway: .B :.0 (Attached Exhibit # ) Q) typical greatest !f1 Are longitudinal culvert ends in compliance with 8-CS Standard Specifications? Yes No, then explain: <( (/) At intersections or otherwise, do valley gutters cross arterial or collector streets? ..c Q) No Yes If yes explain: 5 "" >---() "'O I ..c:. Q) -(/) "§: Are valley gutters proposed to cross any street away from an intersection? (/) Q) -::::: Q) ::I 0 No Yes Explain: (number of locations?) ~ O>Z ----]~\, Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) € Q; Gutter line slopes: Least Usual Greatest ::I :t:: "" Are inlets recessed on arterial and collector streets? Yes No If "no", () ::I "'O ----:;; Cl Q) identify where and why. "'O (/) 3 :ii ::I STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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. Will inlet size and placement prevent exceeding allowable water spread for 10-year design storm throughout site (or phase)? --Yes --No If no, explain. 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. 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 Pipe runs between system I Typical ~ U) Longest ::> Q) access points (feet): E >-~I Are junction boxes used at each bend? --Yes --No If not, explain where and why. U) .s 0 jt1 Are downstream soffits at or below upstream soffits? Least amount that hydraulic U) grade line is below gutter line .!!!. Yes No __ If not, explain where and why: --(system-wide): Part 4 - Drainage ConceRt and Design Parameters I 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). :J ro o, a. ..... ~ 1) Watercourse (or system), velocity, and angle? :; Q) a.. ~ U) a; ::> c Q) 0 &::> ~o..c 0 -U) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 2) Watercourse (or system), velocity, and angle? 3) Watercourse (or system), velocity, and angle? For each outfall above, what measures are taken to prevent erosion or scour of receiving and all facilities at juncture? 1r:e~ ~ f -\2.-hf 2) 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): <'-· rn Q) ~ rn ..... Cll Flow line slopes (minimum and maximum): ~ >- ! I -g 0 ri rn Outfall characteristics for each (velocity, convergent angle, & end treatment). Cll ..... Will 100-year design storm runoff be contained within easement(s) or platted drainage ~ ROW in all instances? --Yes --No If "no" explain: Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase.pr Site) (continued) IS! rn Are roadside ditches used? ~No __ Yes If so, provide the following: rn Cll Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes No ~ Cll "fi -- 0 :!::: Are top of banks separated from road shoulders 2 feet or more? __ Yes --No p::: 0 Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No ---- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 2) Watercourse (or system), velocity, and angle? 3) Watercourse (or system), velocity, and angle? For each outfall above, what measures are taken to prevent erosion or scour of receiving and all facilities at juncture? 1J.e'.~ ~f-~ 2) 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): Flow line slopes (minimum and maximum): Outfall characteristics for each (velocity, convergent angle, & end treatment). Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in all instances? __ Yes __ No If "no" explain: Part 4 -Drainage Conce~t and Design Parameters J Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase.yr Site) (continued) ~ IJ1 Are roadside ditches used? ~No __ Yes If so,-provide the following: IJ1 Cll Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes No tg Cll -5 -- 0 ~ Are top of banks separated from road shoulders 2 feet or more? __ Yes --No ~ 0 Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No ---- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY For any "no" answers provide location(s) and explain: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: "' Q) >- lw Is 100-year design flow contained in conduit/swale combination? --Yes --No If "no" explain: c: 0 l1l ~I~ Space for 100-year storm flow? ROW Easement Width Swale Surface type, minimum Conduit Type and size, minimum and maximum 0 and maximum slopes: slopes, design storm: :;:::; C'-· '5 "' Q) "O l1l c: >-Inlets Describe how conduit is loaded {from streets/storm drains, inlets by type): c: l1l c: ..c: l1l 0 ..... c: .E Q) c: Q. 0 0 ~ Access Describe how maintenance access is provided (to swale, into conduit): -l1l 0 E :J ..... ~ .E .5 .5 Q) "O E Instance 2 Describe general location, approximate length: Q) l1l "' "' :J "' Q) c: "O .Q ·::;; Is 100-year design flow contained in conduit/swale combination? Yes No ro 0 -- --..... If "no" explain: c: Q. :.c -Q) E Q) 0 ..c: Space for 100-year storm flow? ROW Easement Width 0 "' -Q) Swale Surface type, minimum Conduit Type and size, minimum and maximum :J ro "O ..... and maximum slopes: slopes, design storm : c: l1l 0 Q. 0 Q) -... "' Q) Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): 1 c: ~ "' ~ <( Access Describe how maintenance access is provided (to swale, into conduit): Part 4 -Drainage Conce ~t and Design Parameters I Continued (Page 4. 7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) "O If "yes" provide the following information for each instance: "' Q) Q) ·-Instance 1 Describe general location, approximate length, surfacing: Iii ::; "' :!= ..0 , tn °S I -0' ~=· ·::= STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX Qi i:: i:: tU ..c: (.) APPENDIX D -TECHNICAL DESIGN SUMMARY 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: Instance 2 Describe general location, approximate length, surfacing: Is 100-year design flow contained in swale? __ Yes __ No Is swale wholly with in drainage ROW? __ Yes __ No Explain "no" answers: Access Describe how maintenance access is provided: 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 charyielized (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. Will design replicate natural channel? __ Yes __ No If "no", for each instance describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow, and amount of freeboard: Instance 1: Instance 2: Instance 3: Part 4 -Drainage Concept and Design Parameters I 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 _.!L._ Yes -E ~ If "ves" provide the information below. / Qi ~"ll-~'---L-~~~~~~~~~~~~~~~~~~~---,,,__~~~~~~~--; i:: E Will small creeks and their floodplains remain undisturbed? _L Yes No How ~ ~ :. many disturbance instances? Identify each planned location: ..c: 0 (.) a. £ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX Qj c c 111 ..c: u APPENDIX D -TECHNICAL DESIGN SUMMARY 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: Instance 2 Describe general location, approximate length, surfacing: 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 provided: 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 chal)Jlelized (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. Will design replicate natural channel? __ Yes __ No If "no", for each instance describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow, and amount of freeboard: Instance 1: Instance 2: Instance 3: ."5t...1b-tf\ ~l-oc:k!U3N cF- ~ ~F--L- Part 4 -Drainage Concept and Design Parameters I 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 -E < If "ves" provide the information below. / ~ ~ "ll, -W~il'-1 s_m__,_a_ll _c-re_e_k_s_a_n_d_t_h_e-ir_fl_o._od-p-'l-a-in_s_r_e_m_a-in-u-nd_i_s-tu-r-be_d_? _ _L_~_Y_e_s ____ N_o_H_o_w--4 ffi ~ · many disturbance instances? Identify each planned location: ..c: 0 u a. E STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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. Watercourses (and tributaries): Aside from fringe changes, are Regulatory Watercourses proposed to be altered? __ No --Yes Explain below. Submit full report describing proposed changes to Regulatory Watercourses. Address 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: 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 I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: Part 4 -Drainage C o ncei;!t and Design Parameters I Continued (Page 4.9) Sto rmwater Management Co ncept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) \.jrt) How many facilities for subject property project? For each provide info. below. c: For each dry-type facilitiy: Facility 1 Facility 2 0 ; tJj c: Q) Acres served & design volume + 10% ~ ~ c Q) ·-100-yr volume: free flow & plugged o~ Q) u.. ..;c Design discharge (10 yr & 25 yr) ( Spillway crest at 100-yr WSE? __ yes no __ yes no ---- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Berms 6 inches above plugged WSE? 1--yes --no , __ yes --no Explain any "no" answers: For each facility what is 25-yr design Q , and design of outlet structure? Facility 1: Facility 2: Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: __ Yes --No Facility 2: --Yes --No If "no" explain: For each, what is velocity of 25-yr design discharge at outlet? & at spillway? Facility 1: & Facility 2: & Are energy dissipation measures used? --No --Yes Describe type and location: For each, is spillway surface treatment other than concrete? Yes or no, and describe: 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: Part 4 -Drainage Conce~t 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": fl) ~ Facility 1; =:o-(.) Q) 111 :::J u... c: c:.;::;; Facility 2: 0 c: :z:; 0 c: (.) Q) -4i 0 For additional facilities provide all same information on a separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Benns 6 inches above plugged WSE? 1--yes no , __ yes --no -- Explain any "no" answers: For each facility what is 25-yr design Q, and design of outlet structure? Facility 1: Facility 2: Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: __ Yes --No Facility 2: --Yes --No ·If "no" explain: For each, what is velocity of 25-yr design discharge at outlet? & at spillway? Facility 1: & Facility 2: & Are energy dissipation measures used? --No --Yes Describe type and location: For each, is spillway surface treatment other than concrete? Yes or no, and describe: 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: Part 4 -Drainage ConceQt 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": (/) Q) Facility 1; :;::; = :0--~ Q) LL ::J c: c:.;::: Facility 2: 0 c: :;:; 0 c: 0 Q) -Q) 0 For additional facilities provide all same infonnation on a separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 --Yes If "yes", provide information in next two boxes. Will 25-yr. flow pass without flowing over driveway in all cases? --Yes --No Without causing flowing or standing water on public roadway? --Yes --No Designs & materials comply with 8-CS Technical Specifications? __ Yes --No Explain any "no" answers: <'-· Ill Cl c: "iii Are culverts parallel to public roadway alignment? __ Yes No Explain: Ill 0 --..... Ul <.> Q) Q) -ro >- > I ·c Creeks at Private Drives: Do private driveways, drives, or streets cross drainage a. -ro ways that serve Above-Project areas or are in public easements/ ROW? !~1 --No --Yes If "yes" provide information below. How many instances? Describe location and provide information below. Q) Location 1: > s <.> Q) Location 2: 4: Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 100-year flow? For more instances describe location and same information on separate sheet. Part 4 -Drainage ConceRt and Design Parameters I Continued (Page 4.11 ) Stonnwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) <.> Named RegulatoDl Watercourses {&Tributaries}: Are culverts proposed on these Ill= facilities? No __ Yes, then provide full report documenting assumptions, t: ..c Q) ::I criteria, analysis, computer programs, and study findings that support proposed > a. ::; ..... design(s). Is report provided? __ Yes No If "no", explain: <.> ro --~-g. <( Ill ::I STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Arterial or Major Collector Streets: Will culverts serve these types of roadways? No Yes How many instances? For each identify the ----location and provide the information below. Instance 1: Instance 2: Instance 3: Yes or No for the 100-year design flow: 1 2 3 Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? Is velocity limited per conditions (Table C-11)? Explain any "no" answer(s): Minor Collector or Local Streets: W ill culverts serve these types of streets? --No --Yes How many instances? for each identify the location and provide the information below: Instance 1: Instance 2: Instance 3: For each instance enter value, or "yes" I "no" for: 1 2 3 Design yr. headwater WSE 1 ft. below curb top? 100-yr. max. depth at street crown 2 feet or less? Product of velocity (fps) & depth at crown (ft)=? Is velocity limited per conditions {Table C-11)? Limit of down stream analysis (feet)? Explain any "no" answers: Part 4 -Drainage ConceQt and Design Parameters I 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 Ill 'O ditch intersects) provide information requested in next eight boxes. t: Cl.I Do culverts and travelways intersect at 90 degrees? Yes No If not, Cl.I~ ----~:§ identify location(s) and intersect angle(s), and justify the design(s): ~ c: () 0 ~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Arterial or Major Collector Streets: Will culverts serve these types of roadways? No Yes How many instances? For each identify the ----location and provide the information below. Instance 1: Instance 2: Instance 3: Yes or No for the 100-year design flow: 1 2 3 Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? Is velocity limited per conditions (Table C-11)? Explain any "no" answer(s): Minor Collector or Local Streets: Will culverts serve these types of streets? --No --Yes How many instances? for each identify the location and provide the information below: Instance 1: Instance 2: Instance 3: For each instance enter value, or "yes" I "no" for: 1 2 3 Design yr. headwater WSE 1 ft. below curb top? 100-yr. max. depth at street crown 2 feet or less? Product of velocity (fps) & depth at crown (ft)=? Is velocity limited per conditions (Table C-11)? Limit of down stream analysis (feet)? Explain any "no" answers: Part 4 -Drainage Conce~t and Design Parameters j 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 VI 'lJ ditch intersects) provide information requested in next eight boxes. t Q) Do culverts and travelways intersect at 90 degrees? Yes No If not, Q) :J ---- .2: ~ identify location(s) and intersect angle(s), and justify the design(s): :J c 0 0 ~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? __ No __ Yes If yes, identify location(s) and provide justification : Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? --No --Yes If "yes" identify location(s), describe outfall design treatment(s): Is scour/erosion protection provided to ensure long term stability of culvert structural components, and surfacing at culvert ends? __ 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? __ 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? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? --Yes --No If not, explain in Special Design Section of this Part. Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) / Is a bridge included in plans for subject property project? ____IL:._ No --Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? (i) a; Ol -c ·;:: m What drainage way(s) is to be crossed? STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 -ro Plan (SW3P) ::::J 0 established for .... project construction? Cl> ~ --No _LYes 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? _L'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: Part 4 -Drainage Concel;!t and Design Para meters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From 8-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of 8-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements __ Drain system elements --Channel features ~Cu lvert 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 STORMWATER DESIGN GUIDELINES Effective February 2007 I Justification for Deviation (attach additional sheets if needed) Page 22 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 Iii Plan (SW3P) ::J a established for ..... project construction? Q) ~ --No _LYes 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? _LNo __ 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: Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From 8-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of 8-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 STORMWATER DESIGN GUIDELINES Effective February 2007 I Justification for Deviation (attach additional sheets if needed) Page 22 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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? --Yes ~No Briefly summarize the range of applications made of the Rational Formula: What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? acres Location (or identifier): Part 4 -Drainage Conce~t and Design Parameters j Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? 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? __ No --Yes If "yes" identify type of data, source(s), and where applied: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 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; Gutters Conduit Culverts Swales Channels Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: For conduit type(s) Coefficients: Part 4 -Drainage ConceRt an'd Design Parameters I 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: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 24 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 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; Gutters Conduit Culverts Swales Channels Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: For conduit type(s) Coefficients: Part 4 -Drainage Conce~t an'd Design Parameters ] Continued (Page 4.16) Design Parameter~ (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: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 24 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 • SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within limits of sub-critical flow? __ 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? Entrance, friction and exit losses: Bridges Provide all in bridge report Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.17) Design Pa rameters (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 Part 5 -Plans and S~ecificatio ns STORMWATER DESIGN GUIDELINES Effective February 2007 Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3. Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Desi n Summa Draina e Re ort b si nin and sealin below. "This report (plan) for the drainage design of the development named in Part B 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 pennits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued or fall under applicable general pennits. n f=.l A. ff!G-rcW f,t .#'.~~\ ~ -<.t-·····--.~ '· Licensed Professional Engineer ~ '":::> • • • ....lb:, • • • ' L*..-~ ··.'\fJ State of Texas PE No. 8t3S 8-:b 2 .~: • • • • • • • • • • • • • • • • • i STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of26 APPENDIX. D: TECH . DESIGN SUMMARY As Revised February 2008 • SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill, Paragraph C3. Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Desi i1 Summa Draina e Re ort b si nin and sealin below. "This report (plan) for the drainage design of the development named in Part B 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 have been issued or fall under applicable general permits. n r=..i A. -!fk-rc/}l_f f .t ,:~~\\ """"' -<,.II'-•••••• -.~ '· Licensed Professional Engineer ~ e:, • • ~ • • ' L*:·· ~ ···."\I~ State of Texas PE No. 8'3S 8-:b i .~: • • • • • • • • • • • • • • • • • ~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008