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HomeMy WebLinkAbout06 - Design Report - Meadow Creek Ph II & III - Stormwater ,► ENGINEERING , INC . A Consulting Engineers and Land Surveyors is STORM WATER MANAGEMENT DESIGN REPORT FOR Meadow Creek Subdivision, Phases II & III Bozeman, Montana Prepared For: Meadow Creek Partners, LLC 924 Stoneridge Drive, Suite 1 Bozeman, MT 59718 April 2006 BOZ-05021.02 705 Osterman Drive, Suite F Bozeman, MT 59715 Phone 406.522.9876 Fax 406.922.2768 info.bozeman@enginc.com www.enginc.com STORM WATER MANAGEMENT DESIGN REPORT FOR Meadow Creek Subdivision, Phase II & III Bozeman, Montana Prepared For: Meadow Creek Partners,LLC 924 Stoneridge Drive, Suite 1 Bozeman,MT 59718 Prepared By: inENGINEItAN%wr INC. Consulting Engineers and land Surveyors Maras ■ 80nMAH April 2006 BOz-05021.02 TABLE OF CONTENTS Pg. Introduction................................................................................................... 1 Site Location and Description.............................................................................. ExistingConditions.......................................................................................... 1 Soils................................................................................................... 1 Drainage.............................................................................................. DesignMethodology........................................................................................ 2 Design Considerations.............................................................................. 2 SubbasinInformation............................................................................... 2 Storm Runoff Calculations................................................................................. 3 Rational Method Calculations..................................................................... 3 Gutter and Inlet Capacity Calculations........................................................... 4 Sidewalk Chase Capacity........................................................................... 5 Pipe Sizing Calculations........................................................................... 5 Detention Pond Calculations....................................................................... 5-6 Summary...................................................................................................... 6 References.................................................................................................... 7 Stormwater Exhibit LIST OF APPENDICES Appendix A—Soils Information Appendix B—Inlet and Gutter Calculations Appendix C—Pipe Sizing Calculations Appendix D—Gutter Capacity Calculations Appendix E—Detention Pond Calculations Appendix F—Outfall Structure Sizing Appendix G—Sidewalk Chase Sizing LIST OF TABLES Table 1 —Rational Method Detention Basin Sizing (1 0-YearDesign Storm)...................... 3 Table 2—Rational Method Inlet Basin Results (25-Year Design Storm)........................... 3 Table 3 —Inlet Capacity Summary: 25-Year Design Storm.......................................... 4 Table 4—Pipe Sizing Summary: 25-Year Design Storm............................................. 5 Table 5 —Detention Pond Sizing Summary: 10-Year Design Storm................................ 6 P:PM\BOZ-05021_02_STORiNI-DESIGN_REPORT i INTRODUCTION This design report summarizes the management plan for storm water runoff within Meadow Creek Subdivision,Phases II and III, located in Bozeman,Montana. The information contained in this report provides the basis of design for the required storm drainage improvements to be completed. The completed improvements will be under the ownership and maintenance of the Meadow Creek Home Owner's Association (MCHOA) and the City of Bozeman. The MCHOA will be responsible for the maintenance of the detention pond areas and the City of Bozeman will be responsible for the conveyance system that feeds the detention ponds. The methodology and analysis procedures utilized in this report are in conformance with the design standards found in the City of Bozeman Design Standards and Specifications Policy,March 2004. Recommendations made in this report are based on these standards and the professional judgment of the author. SITE LOCATION AND DESCRIPTION Phases II and III of Meadow Creek Subdivision are located on Certificate of Survey No. 2286. Generally, the property is bordered on the east by Phase V;Phase I to the north;Phase IV to the west; and Certificate of Survey No. 2177 to the south. Phases II and III of the development will contain five high-density lots with approximately seventy- two dwelling units in the five lots. There are six four-plex lots, nine three-plex lots, six duplex lots and forty-two single family unit lots. There are six proposed local streets and one collector to serve Phases II and III. The two local streets are an extension of Enterprise Boulevard, Goldeneye Drive, Meadow Creek Drive,Last Loop Drive, Parkway Avenue, and South 23rd Avenue. The proposed collector is Blackwood Road which will be extended east to connect to South 19th Avenue. Each of the internal local and collector streets will be constructed to City of Bozeman standards, having appropriate right-of-way widths of 60-feet and 90-feet respectively, and street widths of 33-feet and 48-feet from back-of-curb to back-of-curb respectively. Boulevard sidewalks,located seven and a half feet behind curb and gutter,will be installed at the time building construction occurs on the lots. EXISTING CONDITIONS Soils According to the Soil Survey of Gallatin County Area,Montana (1996), the natural soil type is predominantly Turner Loam and Meadowcreek Loam. Groundwater in the development area is as high as 18-inches below the natural surface to 8-feet below the surface. Dewatering techniques will be used during construction to control groundwater. The site soils are gently sloping with moderate organic-matter content. The risk of soil blowing and water erosion is moderate to low. The existing area is primarily rangeland, having a moderate cover of native vegetation. A brief summary of the soils located in the subdivision is located in Appendix A of this report.A more detailed description of the soils in this development can be found in the Geotechnical Report for Meadow Creek Subdivision (December 2005,Allied Engineering Services, Inc.). P:PM\BOZ-05021_02_STOR 4 DES REP_PHII_III 1 04/03/2006 Drainage The existing ground is sloped, having an approximate 2%gradient from south to north. Surface runoff currently drains to existing creeks that run from south to north through Phases I, II, and III of the development. Some runoff drains via sheet flow to the northern boundary of the development and eventually finds its way to the creeks that flow to the north from the property. Runoff from adjacent property to the south does not enter Phases II and III of the subdivision. Runoff from the southern boundary of Phase III flows to the existing creeks which flow through the development from south to north. Some areas in Phases II and III have already been analyzed as part of the Stormwater Design Report for Phase I of Meadow Creek Subdivision. DESIGN METHODOLOGY Design Considerations Phases II and III of Meadow Creek Subdivision have a gross area of 82.77 acres. It is proposed to utilize gutters and inlets to collect stormwater runoff from Meadow Creek Subdivision,Phases II and III. The gutters and inlets will connect to detention areas located throughout Phases II and III. The detention areas will be designed to release only the pre-developed runoff from the 10-year design storm event. In addition to Phases II and III of Meadow Creek Subdivision, other phases of the subdivision will contribute to runoff to be collected in detention ponds located on Phases II and III. Runoff from the contributing basins has been included in the analysis to properly size the detention pond as well as the conveyance system which feeds the pond. Some of the area in Phases II and III will be park and wedand area which will remain in pre-developed runoff condition and therefore this area was not analyzed as part of this report. A stormwater exhibit has been included which delineates the drainage basins that drain to the detention ponds as well as the gutter and inlet sub-basins that represent basins for the conveyance of the runoff. The detention ponds located in Phase II and III have been sized using the 10-year design storm event with pre-development runoff as required by the City of Bozeman Design Standards and Specifications Policy. All conveyance systems including gutters,inlets, and storm piping have been sized to accept the 25-year design storm as required by the City of Bozeman Design Standards and Specifications Policy. The Rational method was used in calculating the storm runoff from the proposed development and all contributing areas. Sub-basin Information The stormwater runoff analysis area for Meadow Creek Subdivision,Phases II and III,has eight drainage basins which drain to eight detention pond areas. These eight drainage basins have been divided up into smaller sub-basin areas. The sub-areas are either gutter basins or inlet basins. The gutter basin areas were used to determine if the critical areas in each basin were capable of conveying the 25-year design storm without the need to place inlets. The inlet basins show areas that feed the ten inlets located in the eastern portion of Phases II and III, as well as the western portion of Phase V. These basins can be seen on the stormwater exhibit that is included in this report. STORM RUNOFF CALCULATIONS P:PM\BOZ-05021_02_STORitiI_DES_REP_PHII_III 2 04/03/2006 Rational Method Calculations Storm water runoff calculations were performed using the Rational Method as outlined in the City of Bozeman Design Standards and Specifications Policy. A Rational Method"C" factor of 0.35 was used for basins that contained low to medium density residential lots. The "C" factor of 0.60 used for basins that contained only right-of-way area was taken from a weighted average of"C" factors contained in Hydrologic Analysis and Design, Second Edition (McCuen). Table 1 and Table 2 summarize the results of the Rational Method calculations used to size the detention ponds and the conveyance systems in Phases II and III of Meadow Creek Subdivision. More detailed calculations can be found in Appendix B and Appendix E of this report. Table 1 Rational Method: Retention Pond Sizing (10-Yr Storm) Drainage Basin Area (Acre) "C" Factor Required Storage (cf) 5A 3.74 0.35 1,523 5B 3.09 0.35 1,258 6A 7.31 0.35 2,741 6B 0.40 0.60 174 7 11.15 0.35 3,994 12 14.19 0.35 5,082 15 2.11 0.35 633 16 1.66 0.60 818 Table 2 Rational Method: Inlet/Gutter Basin Results (25-Yr Storm) Inlet/Gutter Basin Area (Acre) "C" Factor Peak Runoff(cfs) Gutter Basin 5A 3.74 0.35 2.46 Gutter Basin 5B 3.09 0.35 1.81 Gutter Basin 6A 6.99 0.35 2.63 Gutter Basin 6B 0.40 0.60 1.35 Gutter Basin 15 2.11 0.35 1.67 Gutter Basin 16 0.83 0.60 1.40 Inlet Basin S1 2.04 0.35 1.46 Inlet Basin RI 2.05 0.35 0.80 Inlet Basin T1 3.42 0.35 1.47 Inlet Basin T2/T3 6.68 0.35 3.97 Inlet Basin U1 5.00 0.35 2.39 Inlet Basin U2 4.81 0.35 2.20 Inlet Basin U3 1.34 0.60 1.80 Inlet Basin V 1 0.83 0.60 2.08 P:PiM\BOZ-05021_02_STOR -DDES_REP_PHII_III 3 04/03/2006 Gutter and Inlet Capacity Calculations The City of Bozeman Design Standards and Specifications provides that for city streets, the flow in the gutters shall not be greater than 0.15 feet below the top of the curb. Calculations for available gutter capacity for various street locations are located in Appendix D. These gutter capacities were used to determine if inlets are needed to convey the 25-year flow. Inlet capacities for the on-grade inlets were determined using dimensional data for a D &L Foundry I-3519 inlet and the following: Q = Kd5/3 Q = captured flow (cfs) K= inlet grate coefficient from Neenah Foundry K-charts d = flow depth of runoff at inlet (ft) Ponded inlets will collect any flow directed to low points in the gutter. The capacity of the inlet was calculated using a gutter depth of 0.35 feet (0.15 feet below top of curb). Using the nomograph contained in the Neenah Foundry Company Catalog"R", 11th Edition (I-3519 inlet), the inlet capacity for the inlet was determined to be 3.1 cubic feet per second. This capacity was used to determine spacing and density of inlets at low points in the gutter. The calculated capacities for the inlets proposed within Meadow Creek Subdivision,Phases II and III, are summarized in Table 3. More detailed calculations for the inlet capacities can be found in Appendix B. Table 3 Inlet Capacity Summary: 25-Year Design Storm Total Theoretical Flow Allowable Flow Captured By-Pass Gutter Down- To Flow Into From Flow Inlet stream Subbasin Inlet Inlet Inlet At Inlet Inlet Type Inlet# Area (cfs) (cfs) (cfs) (cfs) S1 On-Grade NA Inlet Basin S1 1.85 1.85 0.00 5.11 R1 On-Grade NA Inlet Basin R1 0.80 0.80 0.00 2.73 T1 Ponded NA Inlet Basin T1 1.47 1.47 0.00 3.10 T2 Ponded NA Inlet Basin T2/T3 3.97 3.1 0.87 3.10 T3 Ponded NA Inlet Basin T2/T3 0.87 0.87 0.00 3.10 U1 On-Grade R1 Inlet Basin U1 2.82 2.43 0.39 4.32 U2 On-Grade R1 Inlet Basin U2 2.20 2.20 0.00 2.73 U3 On-Grade R2 Inlet Basin U3 1.80 1.80 0.00 4.32 V1 Ponded NA Inlet Basin V1 1.80 1.80 0.00 3.10 V2 On-Grade V1 Inlet Basin V1 0.28 0.28 0.00 2.73 P:PM\BOZ-05021_02_STORttii_DES_REP_PHII_III 4 04/03/2006 Detention Pond Sizing Calculations There are eight proposed detention ponds located in Phases II and III of Meadow Creek Subdivision. These eight ponds will detain storm runoff from the eight drainage basins as shown on the Stormwater Exhibit. The detention ponds were sized to hold the 10-year design storm event while releasing only the pre-developed runoff from the basins. All ponds were designed to allow for treatment of the stormwater and have adequate surface area to allow for particle settling. Infiltration was not included in the calculations to be conservative. Discharge structures will be designed to limit the flow out of the detention ponds to the pre-developed runoff flow. Sizing for the discharge structures can be found in Appendix F. Overflow areas for the ponds will direct flow from storm events greater than the 10-year event to natural drainage areas. Overflow during these events will not flood or damage any structures on the site. A summary of the detention pond sizing calculations is in Table 5. More detailed calculations can be found in Appendix E. Table 5 Detention Pond Sizing Summary: 10-Year Design Storm Drainage Required Required Surface Area Pre-developed Detention Pond Basin Storage (cf) with 1.5 ft depth (sf Runoff(cfs) 5A 5A 1,523 1,016 0.47 5B 5B 1,258 839 0.39 6A 6A 2,741 1,828 1.07 6B 6B 174 116 0.21 7 7 3,994 2,663 1.77 12 12 5.082 3,388 2.26 15 15 633 422 0.47 16 16 818 546 0.68 SUMMARY The included analyses and calculations show that the proposed storm water management system for Meadow Creek Subdivision,Phases II and III,will adequately store the 10-year storm event and adequately convey the 25-year storm event.Available gutter capacity and the location and spacing of inlets will limit encroachment of runoff on pavement surfaces to acceptable levels. The recommended pipe sizes would effectively convey storm runoff from Meadow Creek Subdivision, Phases II and III, to designated detention areas. Therefore, the proposed stormwater managements system meets the requirements of the City of Bozeman Design Standards and Specifications Policy and will satisfy the needs of the owner of the property. P:PM\BOZ-05021_02_STORM__DES_REP_PHII_III 6 04/03/2006 REFERENCES 1. McCuen, Richard H. (1998). Hydrologic Analysis and Design, Second Edition. Upper Saddle River, NJ: Prentice Hall. 2. City Engineering Division. Quly, 2005). Design Standards and Specifications Pgh . City of Bozeman,Montana: Author. 3. Allied Engineering Services, Inc. (2005). Geotechnical Report, Meadow Creek Subdivision, South 19t'Avenue,Bozeman, Montana.: Author. 4. United States Department of Agriculture Soil Conservation Service; Natural Resources Conservation Services; and Montana Agricultural Experiment Station. (1996). Soil Survey of Gallatin County Area, Montana. Washington, DC: U.S. Government Printing Office P:PM\BOZ-05021_02_STORiiM-DES_REP_PHII_III 7 04/03/2006 STORMWATER EXHIBIT PRELIMINARY PLAT OF MEADOW CREEK SUBDIVISION TRACT I SURVEY ICNTE2008 LOT 25 N �LOT 26 NNES 72-31f 3 m PARK SUB. LOT 27 4 TRACT 1 [y 3 CERTIFICATE OF SURVEY No. 1989 BEING A PORTION OF TRACT 2 DESCRIBED ON PLAT BK. 152 PG. 474 AND FILM 9 PG. 11569IL F 738.73 LOT 4 OF MINOR SUBDIVISION No. 235, CERTIFICATE OF SURVEY No. 2286 AND THE SE 1 /4 OF — — - .�T DE—pDR THE SW 1 /4 OF SECTION 23, DESCRIBED ON FILM 115 PG. 3747, T. 2 S.9 R. 5 E.9 P.M.M. �' a BOZEMAN, MONTANA I naaw. = LOT -BLOCK 1- MINOR SUBDIVISION No. 235 E Z LERNEAPARN z6sea IF EE�YJIort - - - 8 STUBBLE LANE _ PREPARED FOR MEADOW CREEK PARTNERS, LLC APRIL, 2005 ;- PREPARED BY ��ENGINEERING, INC. 200 BOZEGMAN, MONTANAGD I E SCALE 1 = 200 100 E 9 FM 1156 � -BLOCK 2- Po"o a z x, Il,rro ss LOT 2 m MINOR SUBD/VISION No, 295 limit � ' A TRACT f CERTIFICATE OF SURVEY No. 2122 I m seers s< N 2611'10"E _ 0 I 78.28' A C BASIS OF BEARING: BEARINGS ARE GEODETIC, DERIVED FROM GPS N 0425'12"E h e t s ao43'ze w *. OBSERVATIONS WITH SURVEY GRADE RECEIVERS z3.zo o n.29 'yy4y4 93-188 S 88'S3'38"E 562.85' AND REFERENCED TO THE MERIDIAN AT WGS 84. _ o FOUND SURVEY MONUMENT, AS NOTEDF "wau^ GRAF STREET o*r — o afr u N = SET 5/8" X 18" REBAR WITH CAP MARKED WITH THE xcv a woE I n,.sr LICENSE NUMBER OF THE UNDERSIGNED LAND SURVEYOR I I Z an"Ds AND "ENGINEERING INC BILLINGS MT" 4 0„og N" SETBACK -BLOCK 3- F -BLOCK 4 m u F"1 n onwJ sr I---- A- I m en NDS _ LOT 3 MINOR SUBDIVISION No. 235 I s �B.p B,r xEM«"Ys 0 TRACT A s CERTIFICATE OF SURVEY NA 1861 I 'a,R's 11 sr ` was s t TRACT f CERTIFICATE OF I wd" ENTERPRISE BOULEVARD1211.1 SURVEY No. 2074 11-IF 2 ,y 111.v aaNIF E .1.SE -BLOCK 5- N 2% ,a Il BLOCaJKa, =2i 6- m$,xaazx sr BCNx1: Ta ycK I a°Js°ss°,a;ss aoJoo6JJJs'Or sorT s ss e,ssa �°Js r�oau a� 1a N ' TLA"�Ds SCARLETT LANE a sa`zx,n SE a s r- =40 a z I z 8 lz IS 12'429.1'47 Y Es ET z n BLAKE DRIVE- OLEGE STRE ,naox s` A nxx22 . xexzee sr Isrsssa°,e ssr l NAto eamoxaRtaOesss sz,esss r` uazgs _VN r 1. ee = 21,zss D ss wJ MEADOW CREEK DRIVE a .n :pE uaa_mN u I C8a�SaO-u-L Ega8a DRIVE 1xss a sPARK 2—s z.seD qa - - rF� O -1 a noo 90 s< K - 23 o °a a a u w8a a a a a s s KAGY BLVD N_w�C-4''8, ,Ixexsn sBoro ss ID Am^',„IJxno,wzJs,Teo Ts zsss1s r 3s s s13 rz -(,,aJIa°aa.Jos'assrs rD=1 mu"_e._s°1 5 ysY cuos YYEasww9 s@ ZO=o 0_aJ - ,„soax°sIJ a ssr rr mN-2� ,°°Jm a SEiBaAG aoaawJ xns„nr°sse^ss O `1�0Kc`z"Psry sss :u.y D,zsBeJnsa,,o'osss ssfa sr eelJaBzs.ss ssrsr mCDZO-C I ms�x Jw"',s z°sB° L x O.vxC 8.NzK xas r 2,z apN E w$uou$mFmD 146 FM 3339 < r s° s D nzm 4 z m STU z J A z "K � PINTAIL DRIVE rULR - eN .� -BLOCK 9- -BLOC �2_ ,o IF � N ,E D O n s zw sr o Wo}n m D 0ITE z °ss 2si s Z r�• 80-358a-: > ss s ss 13 D < ,o Z 146 FM 334/ z D azs z x Zzz.o < ANDS m BUSHNELL STREET BLOC REE LANE _JL 116,1, 85S, Jo s B w —S L Y AN o zx sGO _ x Y aLDENST N 148 FM 3337 ALL 0050 i `4� r*1 Bl CK si _ so sr n� L CK 11 a. 1, '• ,a B ,Bss w ° °pJ Ds a zx sr srSETRACK zz VICINITY MAP N 88•49.22'W 132827• nn BLACKWOOD ROAD :'As. N 8838'OB'W 2597.95' TRACT 2 8E_f41 CERTIFICATE OF SURVEY N. 2177 MEADOW-PP-AM.DWG ROZ-05021 CMK 4 18 06 'I I LEGEND . -DRAINAGE BASIN BOUNDARY y \� -SUB-BASIN BOUNDARY c �___ \ � z T N J - STORM DRAIN INLET W Z y\ SCALE 1" — 100' ) 54 \ \ \ `-\`._-_ ROW DIRECTION , . y r 0 - 1 I IM �� - I I AS � l ' vGU 1� B SI 67 CD )' I i — — _S I �I I I fI f /II fI '-1 (NLT � -'I 1f 1 � -1=� -1 � I Ill m (� I I I f`� ��f ,�� - - I �� - 1 L�II�� B �%N-�-Rlj _ � l� � � \ N ui r � , ab� I �I i l� I I �E BAIN �T1 1 J _ I I a W Q �, <a- z w _ _ — — — - - - - - - - -I �l \ o <z ? Tw -- -� _- -III , I ' ' w (A w N o 0 NI� `-I1= L�E I I I f Y o o - _ / o Q [7 I �, CA.D. CMK DATE: 4/7/06 REMsioNs: 4i18/06 i —✓/ �� / — — ; �� - i / �' �— _ �� APPROVED BY: /� ; f OUALRY ASSURANCE: \ = - �'� � SCALE: i'_too' �I FlLE:PHASEII&III_STOR PROJECT NO.:Boz—osos,.oz SHEET—OF— T J _ APPENDIX A SOILS INFORMATION a.• �•. •r _ _ .. -® ?" r••rf iv.-.:�;,,,'r.•;ar'ipl;,:cYc•'.`•fYi.• ;,••y •..1<'•• ,fir,,`i.! .,�„r •I. it tC•. p 1•s, '1 •I •.ji• •� ..R.. •f'-i:J-r r.i f.yqp� '}• A°I: G'�•. t�f' `ir�- yt '�..f..•�� Iti� .I `'� ,`:' 1 -V �:�t' X •f:^ y �}� .�^� 1•+t4'� .r � }�7:.- j ry'. :- t..c:4�"L'Y• '4't�'t` aR� ,r t:�•. l�,r Y 4[:. :;Sy.,�,'1{.�. 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It 44M 1 .: l,r,.: :•i .� #�'; '. ? I::.;:: r .�' i :,. i" t " .,as.-:/5.,. �r� r,..,..- C� r'•�`� �� �7b2EY. �I �S y •v>r. _ •„1,3, � . �•,�. -.n,• �,1j.,.,. i. Sl' , {b ',r'y4t�,, / /.•r r 1 �• 752E' 65" `kv. __ `++. 7::•11.1 t r 7`{ir".L�i,. t - Ls h.3ts; _ - - 5�9B - «5; r r JL.',. `� t -•-j 'a' M 51DD.!'�s i�, - !�� :-3f a► .�, _.r ���: 6; I n, 72D 1. ; yy,,` r._:,. Sr, •�. ✓-�, p w.' - �f �,,fi•� J�:,rr~ i.••' ''• .!' .. .1:<•;i' ..Ii'.^f-.i"4�' kr� - 44C•1. ./ �. •5,�:; 36 I 51DB 3.1 I 32 �: 65D ti_ j 64B 752E0 ssc' s•37'3o"N II R.5 E. R.6 E. 407A_ 11 °W r[ ' 111°2'30"W 497000 49800O 499000 '•yt 493000 111°5 W 494000 495000 496000 49f000 492o.o (Joins sheet 40, Wheeler Mountain) 1 D 1 MILE N 1000 0 1DDD 20DO 3000 40D0 50D0 6DDO 7DD0 FEET -his soil survey map was compiled by the U.S.Department of '^riculture,Natural Resources Conservation Service,formerly Soil 1 0 1 KILOMETER SHEET NUMBER 35 OF 45 nservation Service,and cooperating agencies. Base maps are Scale 1:24000 GALLATIN COUNTY AREA, MONTANA -hophotographs prepared by the U.S.Department of the Interior, ♦__1--.__,n..-._.. L-_�,A/YC--..I-L_1--_--L.. !•_--J:-mil-_-:J J V) CL O O n. Q) r r T y C o o Z Lo N Z m a � o T o o O0 C, 0 '5'E r� v J N m Cl N N a a. m {{E 0 00 L LV) LO In h h n N CDto m LO a 'a' E E E m c LO o L'] no LO o LO O m m -1) M M m N =. to m C n N O O O O O O U'l O O W C r r r n LO o d m y 4 0 0 _� o 0 o c _ _ O lA L7 N Lh IA LOO O O m m d E y o ayi o o 'o o m .H LLi 4 r r CD a ' o c '� c od - N c at i uo CDto Q a A C O O, C) 0 � .m O C O Oci ro O cc •` c75 cu a) U m Q C Q 4 < 4 4 Q m` > 0D to C m y s s ro Q C m UU UU n n U a W U U�. U U (7 C7-� U U N C9�- - H CD ` i c c _ m co o ro ro ro ccu Q `7 C9 N y N Q N cJ -_ (0. 2 2 E O T CD CD° C7 r cn im o � ; � E.. �mv = > rov E coro rD J M LO N i � o d E c v o � M Co ro 0 o E ^ E � J ro y ~ `O �'� 250 Soil Sul nonplastic; 10 percent cobbles and 40 percent Major Component Description pebbles;slightly alkaline. Surface layer texture:Loam Range in Characteristics Depth class:Very deep (more than 60 inches) Soil temperature:43 to 47 degrees F Drainage class:Somewhat poorly drained Moisture control section:Between 4 and 12 inches Dominantparent material.•Alluvium Mollic epipedon thickness:10 to 15 inches Native plant cover type:Rangeland Depth to seasonal high water table:24 to 42 inches Flooding.-None Depth to the 2C horizon:20 to 40 inches Water table:Apparent A horizons Available water capacity. Mainly 4.9 inches Hue: 10YR or 2.5Y A typical description with range in characteristics is Value:2 or 3 moist;4 or 5 dry included, in alphabetical order, in this section. Chroma: 1 or 2 Texture: Loam or silty clay loam Management Clay content: 18 to 35 percent For management information about this map unit, Content of rock fragments:0 to 5 percent pebbles see appropriate sections in Part II of this publication: Electrical conductivity(mmhos/cm):0 to 8 Reaction:pH 6.6 to 3.4 Bghorizons 504A—Meadowcreek silty clay loam,. Hue: 10YR, 2.5Y,or 5Y 0 to 2 percent slopes Value:3 or 4 moist;5 or 6 dry Setting Chroma: 1,2, or 3 Texture: Loam,silt loam,sandy clay loam, or Landform:Stream terraces sandy loam Slope:0 to 2 percent Clay content: 18 to 25 percent Elevation:4,000 to 5,000 feet Conteht of rock fragments:0 to 5 percent pebbles Mean annual precipitation:10 to 14 inches Electrical conductivity(mmhos/cm):0 to 4 Frost-free period.,95 to.115 days Reaction:pH 6.6 to 8.4 2Chonzons Composition Texture:Sand or loamy sand Major Components Clay content: 0 to 5 percent Meadowcreek and similar soils:85 percent Content of rock fragments:35 to 75 percent-0 to Minor Components 10 percent cobbles;35 to 65 percent pebbles Reaction:pH 6.1 to 7.8 Bonebasin loam:0 to 5 percent Rivra sandy loam:0 to 5 percent 510B—Meadowcreek loam, Ryell sandy loam: 0 to 5 percent 0 to 4 percent slopes Major Component Description Surface layer texture:Silty clay loam Setting Depth class:Very deep (more than 60 inches) Landform:Stream terraces Drainage class:Somewhat poorly drained Slope:0 to 4 percent Dominantparent material:Alluvium Elevation:4,200 to 5,950 feet Native plant cover type:Rangeland Mean annual precipitation:12 to 18 inches Flooding:None Frost-free period.,90 to 110 days Water table:Apparent Composition Available water capacity.,Mainly 5.1 inches Major Components A typical description with range in characteristics is Meadowcreek and similar soils:85 percent included, in alphabetical order, in this section. Minor Components Management Blossberg loam:0 to 10 percent For management information about this map unit, Beaverton loam moderately wet: 0 to 5 percent see appropriate sections in Part 11 of this publication. 356 Soil Sul Flooding:None Parent material.-Sam!consolidated, loamy sediment: Available water capacity.•Mainly 5.2 inches beds Sloe range:4 to 5 percent A typical description with range in characteristics is Elevation range 43.• 00 to 5,500 feet included, in alphabetical order,in this section. Annual precipitation:10 to 14 inches Management Annual air temperature:41 to 45 degrees F For management information about this m2p unit, Frost-free period.•95 to 115 days see appropriate sections in Part II of this publication. Taxonomic Class: Fine-loamy, mixed,superactive, frigid Arfdic Argiustolls 457A—Turner foam, moderately wet, Typical Pedon 0 to 2 percent slopes Udecide cobbly sandy clay loam, in an area of Udecide-Cabbart complex, 15 to 45 percent slopes, in Setting an area of native rangeland, 1,600 feet south and Landform:Stream terraces 1,400 feet east of the northwest corner of sec.20, Slope:0 to 2 percent T. 1 N., R: 1 E. Elevation:4,300 to 5,200 feet A-0 to 5 inches; grayish brown (10YR 512)cobbly Mean annual precipitation: 15 to 19 inches sandy clay loam, very dark grayish brown (10YR Frost-free period.,90 to 110 days 3/2) moist;weak fine subangular blocky structure; Composition soft, friable, slightly sticky, and slightly plastic; Major Components many very fine and fine and few medium roots; 10 percent cobbles and 10 percent pebbles;slightly Turner and similar soils:85 percent alkaline;clear smooth boundary. Minor Components Bt1-5 to 7 inches; grayish brown (10YR 5/2)clay Beaverton cobbly loam:0 to 5 percent loam, very dark grayish brown (10YR 3/2)moist; moderate fine subangular blocky structure;hard, Meadowcreek loam: 0 to 5 percent Turner loam: 0 to 5 percent firm,slightly sticky, and slightly plastic; common Major Component Description very fine and few medium roots;few faint clay films on faces of pads;slightly alkaline;clear Surface layer texture:Loam smooth boundary. Depth class:Very deep (more than 60 inches) Bt2-7 to 12 inches; grayish brown (10YR 5/2)sandy Drainage class:Well drained clay loam, dark brown (10YR 4/2)moist; moderate Dominantparentmaterial.•Alluvium medium subangular blocky structure;hard, firm, Native plant cover type:Rangeland moderately sticky; and moderately plastic; Flooding:None common very fine and fine and few medium roots; Water table:Apparent many faint clay films on faces of pads;slightly Available water capacity.,Mainly 5.2 inches alkaline;clear smooth boundary. Bk-12 to 32 inches; light gray(2.5Y 7/2) sandy clay A typical description with range in characteristics is loam, grayish brown (2.5Y 5/2)moist;weak fine included, in alphabetical order, in this section. subangular blocky structure; hard, friable, slightly sticky, and slightly plastic;few very fine and fine Management roots;common medium masses of lime;strongly For management information about this map unit, effervescent;moderately alkaline;clear wary see appropriate sections in Part If of this publication. boundary. Cr-32 to 60 inches;weakly consolidated sandstone. Udecide Series Range in Characteristics Soil temperature:43 to 47 degrees F Depth class:Moderately de�ep (20 to 40 inches) Moisture control section:Between 4 and 12 inches Drainage class:Well drained Mollic epipedon thickness:7 to 10 inches Permeability.•Moderately slow Depth to the 6k horizon:10 to 22 inches Landform:Hills, sedimentary plains, and escarpments Depth to the Cr horizon:20 to 40 inches �, o APPENDIX B INLET AND GUTTER CALCULATIONS Phase II & III - Basin 5 Gutter Flow Analysis The following calculations were used to verify gutter capacity to capture stormwater runoff. The flows were calculated using the Rational Method, and the conveyance facilities were sized based on a 25-year 2-hour storm event. Gutter Basin(s): 5A A= 3.74 Acre C = 0.35 Low to medium residential Calculate Time of Concentration (T,) Overland Flow Conditions Developed Conditions: S= 2.00% C = 0.35 Low to medium residential Find Sheet/Shallow Concentrated Tc Assume: L= 57 ft. (57 ft. Sheet Flow @ 2%) Using Equation in Section II-E-6 Tc= 8.0 min. Channel Flow Conditions Find Channel Flow Tc (Gutter Flow) Using Mannings Equation, n = 0.013, calculate channel flow Parkway (2+40-9+52) Parkway (9+52-18+00) S= 0.0147 ft/ft S= 0.0144 ft/ft L= 712 ft L= 848 ft R = 0.136 ft R = 0.136 ft v= 3.67 ft/sec v= 3.63 ft/sec Tc(CF)= 3.24 min Tc(CF) = 3.90 min Total T,= 15 min Calculate Post-developed Storm Intensity at T, From Figure 1-3, using the 25 year event, I =0.78Tc o.64 I = 1.88 in/hr Calculate Post-developed Peak Runoff Rate Q= ciA, using the above parameters. Q= 2.46 cfs Minimum capacity on Parkway Avenue is 4.64 cfs. Therefore, the gutter is capable of conveying the flow from the 25-year event. Phase II & III -Basin 5 Gutter Flow Analysis The following calculations were used to verify gutter capacity to capture stormwater runoff. The flows were calculated using the Rational Method, and the conveyance facilities were sized based on a 25-year 2-hour storm event. Gutter Basin(s): 513 A= 3.09 Acre C= 0.35 Low to medium residential Calculate Time of Concentration (Tj Overland Flow Conditions Developed Conditions: S = 2.00% C = 0.35 Low to medium residential Find Sheet/Shallow Concentrated Tc Assume: L= 72 ft. (72 ft. Sheet Flow @ 2%) Using Equation in Section ll-E-6 Tc= 9.0 min. Channel Flow Conditions Find Channel Flow Tc(Gutter Flow) Using Mannings Equation, n= 0.013, calculate channel flow Parkway (2+40-9+52) Parkway (9+52-22+50) S= 0.0147 ft/ft S= 0.0144 ft/ft L= 712 ft L= 1298 ft R = 0.136 ft R= 0.136 ft v= 3.67 ft/sec v= 3.63 ft/sec Tc(cF) = 3.24 min Tc(cF) = 5.96 min Total Tc= 18 min Calculate Post-developed Storm Intensity at T, From Figure 1-3, using the 25 year event, I =0.78TC-1.14 1 = 1.67 in/hr Calculate Post-developed Peak Runoff Rate Q = ciA, using the above parameters. Q = 1.81 cfs Minimum capacity on Parkway Avenue is 4.64 cfs. Therefore, the gutter is capable of conveying the flow from the 25-year event. Phase II & III - Basin 6 Gutter Flow Analysis The following calculations were used to verify gutter capacity to capture stormwater runoff. The flows were calculated using the Rational Method, and the conveyance facilities were sized based on a 25-year 2-hour storm event. Gutter Basin(s): 6A A= 6.99 Acre C = 0.35 Low to medium residential Calculate Time of Concentration (TJ Overland Flow Conditions Developed Conditions: S=2.00% C= 0.35 Low to medium residential Find Sheet/Shallow Concentrated Tc Assume: L= 1000 ft. (1000 ft. Sheet Flow @ 2%) Using Equation in Section II-E-6 Tc= 33.6 min. Channel Flow Conditions Find Channel Flow Tc(Gutter Flow) Using Mannings Equation, n= 0.013, calculate channel flow Meadow Creek Dr. (1+50-5+00) S= 0.005 ft/ft L= 350 ft R = 0.136 ft v= 2.14 ft/sec Tc(cF) = 2.73 min Total T.= 36 min Calculate Post-developed Storm Intensity at Tc From Figure 1-3, using the 25 year event, I =0.78Tc-o.s4 1 = 1.08 in/hr Calculate Post-developed Peak Runoff Rate Q = ciA, using the above parameters. Q = 2.63 cfs Minimum capacity on Meadow Creek Drive is 2.73 cfs. Therefore, the gutter is capable of conveying the flow from the 25-year event. Phase II & III-Basin 6 Gutter Flow Analysis The following calculations were used to verify gutter capacity to capture stormwater runoff. The flows were calculated using the Rational Method, and the conveyance facilities were sized based on a 25-year 2-hour storm event. Gutter Basin(s): 6A A= 0.4 Acre C= 0.6 (weighted) Right of Way(from McCuen) Calculate Time of Concentration (TJ Overland Flow Conditions Developed Conditions: S =2.00% C = 0.60 (weighted) Right of Way(from McCuen) Find Sheet/Shallow Concentrated Tc Assume: L= 0 ft. (0 ft. Sheet Flow @ 2%) Using Equation in Section II-E-6 Tc= 0.0 min. Channel Flow Conditions Find Channel Flow Tc (Gutter Flow) Using Mannings Equation, n = 0.013, calculate channel flow Meadow Creek Dr. (1+50-5+00) S= 0.005 ft/ft L= 350 ft R = 0.136 ft v= 2.14 ft/sec Tc(cF)= 2.73 min Total T,= 3 min Calculate Post-developed Storm Intensity at T. From Figure 1-3, using the 25 year event, I =0.78Tc-o.ea 1 = 5.64 in/hr Calculate Post-developed Peak Runoff Rate Q = ciA, using the above parameters. Q = 1.35 cfs Minimum capacity on Meadow Creek Drive is 2.73 cfs. Therefore, the gutter is capable of conveying the flow from the 25-year event. Phase II &III -Basin 15 Gutter Flow Analysis The following calculations were used to verify gutter capacity to capture stormwater runoff. The flows were calculated using the Rational Method, and the conveyance facilities were sized based on a 25-year 2-hour storm event. Gutter Basin(s): 15 A= 2.11 Acre C = 0.35 Low to medium residential Calculate Time of Concentration (TJ Overland Flow Conditions Developed Conditions: S =2.00% C = 0.35 Low to medium residential Find Sheet/Shallow Concentrated Tc Assume: L= 85 ft. (85 ft. Sheet Flow @ 2%) Using Equation in Section II-E-6 Tc= 9.8 min. Channel Flow Conditions Find Channel Flow Tc(Gutter Flow) Using Mannings Equation, n =0.013, calculate channel flow Parkway Ave. (19+25-22+60) S= 0.0144 ft/ft L= 335 ft R= 0.136 ft v= 3.63 ft/sec Tc(cF)= 1.54 min Total Tc= 11 min Calculate Post-developed Storm Intensity at T. From Figure 1-3, using the 25 year event, I =0.78Tc-0.64 1 = 2.27 in/hr Calculate Post-developed Peak Runoff Rate Q = ciA, using the above parameters. Q = 1.67 cfs Minimum capacity on Parkway Avenue is 4.64 cfs. Therefore, the gutter is capable of conveying the flow from the 25-year event. Phase II & III -Basin 16 Gutter Flow Analysis The following calculations were used to verify gutter capacity to capture stormwater runoff. The flows were calculated using the Rational Method, and the conveyance facilities were sized based on a 25-year 2-hour storm event. Gutter Basin(s): 16 A= 0.83 Acre C = 0.60 (weighted) Right of Way(from McCuen) Calculate Time of Concentration (TJ Overland Flow Conditions Developed Conditions: S =2.00% C = 0.60 (weighted) Right of Way(from McCuen) Find Sheet/Shallow Concentrated Tc Assume: L= 21 ft. (21 ft. Sheet Flow @ 2%) Using Equation in Section II-E-6 Tc= 3.0 min. Channel Flow Conditions Find Channel Flow Tc (Gutter Flow) Using Mannings Equation, n = 0.013, calculate channel flow Blackwood Road(2+00-8+50) S= 0.005 ft/ft L= 650 ft R = 0.136 ft v= 2.14 ft/sec Tc(cF)= 5.07 min Total T,= 8 min Calculate Post-developed Storm Intensity at Tc From Figure 1-3, using the 25 year event, I =0.78TC-o.s4 1 = 2.82 in/hr Calculate Post-developed Peak Runoff Rate Q = ciA, using the above parameters. Q = 1.40 cfs Minimum capacity on Blackwood Road is 2.73 cfs. Therefore, the gutter is capable of conveying the flow from the 25-year event. ; §) 3 G# i): ba/ee . �, ' G 0 uj%L \ 0�■ R § io o |(k/� A © iACL { i §�� ) \0 LL ° l } ; LL k �0 Lu ! io f / '� tu / a ! �/ . 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M N 00 co 00 co 00 CO 00 00 00 CO O co o 0 ¢ 'a O T O T O T O T O O O T T T T O M M M M M M M — M M M — M M M T T T T r T T T C C C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 666666660060060 to NU N - - - - - - - - - - - - - - E � T T T T T T r T T T T T T T T sue+ 0 C6 J J T N J U o W 2 2 2 2 2 2 � 2 2 2 � W W LL LL o > O Z O O Z Z O N (L J M N T T T N M T N > a) 0) f- HF- � (n � W' a. � 222m » a (i E F- F- F- F- F- F- F- 0 F f- c = E E W W W = W 2 W 2 W W W S W W (0 '3 LL J J J J 2 J 2 J J J 2 V) J J >._ ZZZ Z Z ZZZ ZZ N � U � rn rN � � � � � � nnrtiOCOCO (6 a a m IZ IL APPENDIX D GUTTER CAPACITY CALCULATIONS _LL LL LL LL = LLFF p p tnLLLL LL O N In co f7 - O N N fD v IN 00 n m In a m + 1` c M 0 o n N N O 7 p+ NO) 0 0 7 rO O C W 0 O O 00 W IO lD •` N (n CI + Q If II II II II C M v d i II If II II II t7 C ` a 0 C m C Y w uQ�Kyl� < c mQ w�Hln c ? h G1 0 ?CL E vEHrnm nEm °' �ov N 7 C a Y m E 7 C a c >a Q'y m'C O Q m m •o •� p Q a I, m a'LL m a itU a Q m p- dp m o 3 c ro v d i o v m v d 7 U 0! 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J A - �. cl {� \ )!� t cl J = ■ ti § ƒ 7 )�! $ 6 6 \ { k \ � G q ) a g e 5L� j bLLLL j_ § �o / cy CD = 2LIA oo ; 2 O . / 42 IT J4 . g12 , , . . . + g . , . , . - ) § § +-7aE_`Ecc § Cl) [ £ E 2 � | |/// ® _ \ JCL MC(n § kI\ƒ% §e ] �777 . { A 2 . r-\2, • J A § � § ) % J = ) ) a _ = m ~ ° 2 ) { f i \ \ / \ 2 j \ / ° 2 CD CL e . 2 04 2fN = Q � 0 2 - M / » » n V)LLLL E : LOLL» E § o0 0 2 w 2 2 w 2 0 « 2 w2 \aE\. \ /� k ; © LOSE( » CL M . ® 2�\ƒ# §3 , 2 % ��° \ }�\ \ \ 2\ \ \ ¥ ® \ f 7 2 \ { f 7 « o q 2 g e � LL>»LL Euj a " / « E 3 I ` .<. £ E a 2 ■&� § a IL < e, E- _— 0 k ° / « ) ) J = _ 0 a : 2 2 \ 2 4 aE / Jim � & Co aU � 0 2 Lo § LL / ; U- § ; m o,e § 0 2 F 'cm \} 2 ) %\$//7 £ t § § ■ mC( £ \ zz <'oE a (z <ƒ%�2 y a ; 7-/£2 ; f � 2. } G En �� f t J \ ° ; )k] ) J = ± / / / / � \ f ƒ $ \ q R G 2 4 q e APPENDIX E DETENTION/RETENTION POND CALCULATIONS Phase II and III Drainage Basin -5A The following calculations were used to determine the minimum required storage volume for storm water runoff. The volumes were calculated using the Rational Method, and the detention facilities were sized based on a 10-year 2-hour storm event. Pre-developed Conditions Area= 3.74 Acre C = 0.2 Open Land Calculate Time of Concentration (T,) Pre-developed Conditions: S= 1.90% C = 0.20 Open Land Conditions Assume: L=2050 ft. (All overland flow) Using Equation in Section II-E-6 Tc= 62 min. (overland flow) Channel Flow Using Mannings Equation, n =0.035, S= 2.00%, calculate channel flow L= 0 ft R= 0.92 ft v= 5.68 ft/sec T,= 0.00 min Total Tc= 62.00 min Calculate Pre-developed Storm Intensity at Tc From Figure 1-3, using the 10 year event, I =0.64Tc-o.s5 I = 0.63 in/hr Calculate Pre-developed Peak Runoff Rate Q10= ciA, using the above parameters. Q10= 0.47 cfs Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 035 Low to Medium Density Residential 3.74 Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (cfs) (cf) (cf) (cf) 5 3.2185 4.21 1264 141 1123 7 2.5862 3.39 1422 197 1225 9 2.1964 2.88 1553 253 1300 11 1.9278 2.52 1666 309 1356 13 1.7295 2.26 1766 366 1400 15 1.5759 2.06 1857 422 1435 17 1.4527 1.90 1940 478 1462 19 1.3514 1.77 2017 534 1482 21 1.2663 1.66 2089 590 1498 23 1.1936 1.56 2156 647 1509 25 1.1306 1.48 2220 703 1517 27 1.0755 1.41 2281 759 1521 29 1.0266 1.34 2338 815 1523 31 0.9831 1.29 2394 872 1522 33 0.9439 1.24 2447 928 1519 35 0.9085 1.19 2497 984 1513 37 0.8763 1.15 2546 1040 1506 39 0.8468 1.11 2594 1097 1497 41 0.8197 1.07 2640 1153 1487 43 0.7947 1.04 2684 1209 1475 45 0.7716 1.01 2727 1265 1462 47 0.7501 0.98 2769 1322 1447 49 0.7300 0.96 2810 1378 1432 51 0.7113 0.93 2849 1434 1415 53 0.6937 0.91 2888 1490 1398 55 0.6772 0.89 2925 1546 1379 57 0.6617 0.87 2962 1603 1360 59 0.6470 0.85 2998 1659 1339 61 0.6332 0.83 3033 1715 1318 Storage Volume Required = 1523 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles=0.0069 ft/sec Design Release Rate= 0.47 cfs Minimum Area= 68 sf Criteria is met Basin Sizing (Pond 5A) - Detention Water Depth = 1.5 ft Surface Area= 1785 sf (From AutoCAD) Volume= 1538 cf (From AutoCAD) Phase II and III Drainage Basin -513 The following calculations were used to determine the minimum required storage volume for storm water runoff. The volumes were calculated using the Rational Method, and the detention facilities were sized based on a 10-year 2-hour storm event. Pre-developed Conditions Area = 3.09 Acre C = 0.2 Open Land Calculate Time of Concentration (T,) Pre-developed Conditions: S = 1.90% C = 0.20 Open Land Conditions Assume: L=2050 ft. (All overland flow) Using Equation in Section II-E-6 Tc= 62 min. (overland flow) Channel Flow Using Mannings Equation, n =0.035, S =2.00%, calculate channel flow L= 0 ft R= 0.92 ft v= 5.63 ft/sec Tc= 0.00 min _ Total T.,_ 2 ID min Calculate Pre-developed Storm Intensity at T, From Figure 1-3, using the 10 year event, I =0.64Tc-'-" I = 0.63 in/hr Calculate Pre-developed Peak Runoff Rate Q10= ciA, using the above parameters. Qio= 0.39 cfs Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.35 Low to Medium Density Residential 3.09 Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff CVolume Release Volume Required Storage (Minutes) (in/hr) (cfs) ( 928 5 3.2185 3.48 1044 116 1012 7 2.5862 2.80 1175 163 1012 9 2.1964 2.38 1283 209 1121 74 11 1.9278 2.08 1376 256 1121 13 1.7295 1.87 1459 1157 15 1.5759 1.70 1534 348 1185 17 1.4527 1.57 1603 395 441 1208 19 1.3514 1.46 1666 488 1225 21 1.2663 1.37 1726 1238 23 1.1936 1.29 1781 534 1247 25 1.1306 1.22 1834 621 1257 53 27 1.0755 1.16 1884 627 1258 29 1.0266 1.11 1932 1257 31 0.9831 1.06 1978 720 33 0.9439 1.02 2021 767 12 12555 35 0.9085 0.98 2063 813 0 12 37 0.8763 0.95 2104 860 44 39 0.8468 0.92 2143 906 1212 9 37 9 41 0.8197 0.89 2181 52 28 43 0.7947 0.86 2218 99 19 121219 45 0.7716 0.83 2253 08 47 0.7501 0.81 2288 1092 1196 11 49 0.7300 0.79 2321 1138 83 51 0.7113 0.77 2354 1235 1169 53 0.6937 0.75 2386 1 1155 12 3 55 0.6772 0.73 2417 39 1111 57 0.6617 0.72 2447 1324 23 59 0.6470 0.70 2477 1371 1 1107 61 0.6332 0.68 2506 089 Storage Volume Required= 1258 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles =0.0069 ft/sec Design Release Rate = 0.39 cfs Minimum Area = 56 sf Criteria is met Basin Sizing (Pond 5B) - Detention Water Depth = 1.5 ft Surface Area = 1358 sf (From AutoCAD) Volume= 1479 cf (From AutoCAD) Phase II and III Drainage Basin -6A The following calculations were used to determine the minimum required storage volume for storm water runoff. The volumes were calculated using the Rational Method, and the detention facilities were, sized based on a 10-year 2-hour storm event. Pre-developed Conditions Area = 7.31 Acre C = 0.2 Open Land Calculate Time of Concentration (TJ Pre-developed Conditions: S= 1.90% C= 0.20 Open Land Conditions Assume: L = 1320 ft. (All overland flow) Using Equation in Section II-E-6 Tc= 49 min. (overland flow) Channel Flow Using Mannings Equation, n =0.035, S=2.00%, calculate channel flow L= 0 ft R= 0.92 ft v= 5.68 ft/sec Tc= 0.00 min Total T.= 49,00 min Calculate Pre-developed Storm Intensity at T� From Figure 1-3, using the 10 year event, I = 0.64Tc-o.s5 I = 0.73 in/hr Calculate Pre-developed Peak Runoff Rate Q10= ciA, using the above parameters. Q10 = 1.07 cfs Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.35 Low to Medium Density Residential 7.31 Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (Cfs) (cf) ('CO (Cf) 5 3.2185 8.23 2470 320 2150 7 2.5862 6.62 2779 448 2331 9 2.1964 5.62 3035 576 2458 11 1.9278 4.93 3255 704 2551 13 1.7295 4.42 3451 833 2619 15 1.5759 4.03 3629 961 2668 17 1.4527 3.72 3791 1089 2702 19 1.3514 3.46 3942 1217 2725 21 1.2663 3.24 4082 1345 2737 23 1.1936 3.05 4214 1473 2741 25 1.1306 2.89 4339 1601 2738 27 1.0755 2.75 4458 1729 2728 29 1.0266 2.63 4570 1857 2713 31 0.9831 2.52 4678 1985 2693 33 0.9439 2.42 4782 2113 2669 35 0.9085 2.32 4881 2241 2640 37 0.8763 2.24 4977 2369 2608 39 0.8468 2.17 5070 2498 2572 41 0.8197 2.10 5159 2626 2534 43 0.7947 2.03 5246 2754 2492 45 0.7716 1.97 5330 2882 2448 47 0.7501 1.92 5412 3010 2402 49 0.7300 1.87 5491 3138 2353 51 0.7113 1.82 5569 3266 2303 53 0.6937 1.77 5644 3394 2250 55 0.6772 1.73 5718 3522 2196 57 0.6617 1.69 5790 3650 2140 59 0.6470 1.66 5860 3778 2082 61 0.6332 1.62 5929 3906 2023 Storage Volume Required = 2741 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles= 0.0069 ft/sec Design Release Rate= 1.07 cfs Minimum Area = 155 sf Criteria is met Basin Sizing (Pond 6A) -Detention Water Depth = 1.5 ft Surface Area= 2638 sf (From AutoCAD) Volume= 3036 cf (From AutoCAD) Phase II and III Drainage Basin -6B The following calculations were used to determine the minimum required storage volume for storm water runoff. The volumes were calculated using the Rational Method, and the detention facilities were sized based on a 10-year 2-hour storm event. Pre-developed Conditions Area= 0.4 Acre C = 0.2 Open Land Calculate Time of Concentration (TJ Pre-developed Conditions: S = 1.90% C = 0.20 Open Land Conditions Assume: L= 30 ft. (All overland flow) Using Equation in Section II-E-6 Tc= 7 min. (overland flow) Channel Flow Using Mannings Equation, n= 0.035, S=2.00%, calculate channel flow L= 0 ft R= 0.92 ft v= 5.68 ft/sec Tc= 0.00 min Total Tc= 7.00 min Calculate Pre-developed Storm Intensity at Tc From Figure 1-3, using the 10 year event, I = 0.64TC-o.ss I = 2.59 in/hr Calculate Pre-developed Peak Runoff Rate Q10= ciA, using the above parameters. Q10= 0.21 cfs Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.60 Low to Medium Density Residential 0.4 C Value of 0.60 is weighted C value based on Hydrologic Analysis and Design, 2nd Edition, McCuen Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (cfs) (cf) (cf) (cf) 5 3.2185 0.77 232 62 170 7 2.5862 0.62 261 87 174 9 2.1964 0.53 285 112 173 11 1.9278 0.46 305 137 169 13 1.7295 0.42 324 161 162 15 1.5759 0.38 340 186 154 17 1.4527 0.35 356 211 145 19 1.3514 0.32 370 236 134 21 1.2663 0.30 383 261 122 23 1.1936 0.29 395 286 110 25 1.1306 0.27 407 310 97 27 1.0755 0.26 418 335 83 29 1.0266 0.25 429 360 69 31 0.9831 0.24 439 385 54 33 0.9439 0.23 449 410 39 35 0.9085 0.22 458 434 23 37 0.8763 0.21 467 459 8 39 0.8468 0.20 476 484 -9 41 0.8197 0.20 484 509 -25 43 0.7947 0.19 492 534 -42 45 0.7716 0.19 500 559 -59 47 0.7501 0.18 508 583 -76 49 0.7300 0.18 515 608 -93 51 0.7113 0.17 522 633 -111 53 0.6937 0.17 529 658 28-1 55 0.6772 0.16 536 683 -146 57 0.6617 0.16 543 708 64 59 0.6470 0.16 550 732 -183 61 0.6332 0.15 556 757 -201 Storage Volume Required = 174 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles= 0.0069 ft/sec Design Release Rate= 0.21 cfs Minimum Area= 30 sf Criteria is met Basin Sizing (Pond 6B) -Detention Water Depth = 1.5 ft Surface Area = 494 sf (From AutoCAD) Volume= 373 cf (From AutoCAD) Phase II and III Drainage Basin -7 The following calculations were used to determine the minimum required storage volume for storm water runoff. The volumes were calculated using the Rational Method, and the detention facilities were sized based on a 10-year 2-hour storm event. Pre-developed Conditions Area = 11.15 Acre C = 0.2 Open Land Calculate Time of Concentration (T,) Pre-developed Conditions: S= 1.90% C= 0.20 Open Land Conditions Assume: L= 980 ft. (All overland flow) Using Equation in Section II-E-6 Tc= 43 min. (overland flow) Channel Flow Using Mannings Equation, n =0.035, S =2.00%, calculate channel flow L = 0 ft R= 0.92 ft v= 5.68 ft/sec Tc= 0.00 min Total T.= 4100 min Calculate Pre-developed Storm Intensity at T, From Figure 1-3, using the 10 year event, I = 0.64Tr-o.65 1 = 0.79 in/hr Calculate Pre-developed Peak Runoff Rate 010= ciA, using the above parameters. Q10 = 1.77 cfs Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.35 Low to Medium Density Residential 11.15 Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (cfs) (cf) (cfl (cfl 5 3.2185 12.56 3768 532 3236 7 2.5862 10.09 4239 744 3495 9 2.1964 8.57 4629 957 3672 11 1.9278 7.52 4965 1170 3796 13 1.7295 6.75 5264 1382 3882 15 1.5759 6.15 5535 1595 3940 17 1.4527 5.67 5783 1808 3975 19 1.3514 5.27 6012 2020 3992 21 1.2663 4.94 6227 2233 3994 ' 23 1.1936 4.66 6428 2446 3982 25 1.1306 4.41 6618 2658 3960 27 1.0755 4.20 6799 2871 3928 29 1.0266 4.01 6971 3084 3888 31 0.9831 3.84 7136 3296 3839 33 0.9439 3.68 7294 3509 3785 35 0.9085 3.55 7446 3722 3724 37 0.8763 3.42 7592 3934 3657 39 0.8468 3.30 7733 4147 3586 41 0.8197 3.20 7869 4360 3510 43 0.7947 3.10 8002 4572 3429 45 0.7716 3.01 8130 4785 3345 47 0.7501 2.93 8255 4998 3257 49 0.7300 2.85 8376 5210 3166 51 0.7113 2.78 8494 5423 3071 53 0.6937 2.71 8609 5636 2974 55 0.6772 2.64 8722 5848 2873 57 0.6617 2.58 8831 6061 2770 59 0.6470 2.53 8939 6274 2665 61 0.6332 2.47 9044 6486 2557 Storage Volume Required = 3994 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles= 0.0069 ft/sec Design Release Rate = 1.77 cfs Minimum Area = 257 sf Criteria is met Basin Sizing (Pond 7) - Detention Water Depth = 1.5 ft Surface Area= 3657 sf (From AutoCAD) Volume= 4380 cf (From AutoCAD) Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.35 Low to Medium Density Residential 14.19 Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (cfs) (CO (Cry (cf) 5 3.2185 15.98 4795 677 4119 7 2.5862 12.84 5395 947 4447 9 2.1964 10.91 5891 1218 4673 11 1.9278 9.57 6319 1489 4831 13 1.7295 8.59 6700 1759 4941 15 1.5759 7.83 7044 2030 5014 17 1.4527 7.22 7359 2301 5059 19 1.3514 6.71 7651 2571 5080 21 1.2663 6.29 7924 2842 5082 23 1.1936 5.93 8181 3113 5068 25 1.1306 5.62 8423 3383 5040 27 1.0755 5.34 8653 3654 4999 29 1.0266 5.10 8872 3925 4947 31 0.9831 4.88 9081 4195 4886 33 0.9439 4.69 9282 4466 4817 35 0.9085 4.51 9476 4736 4739 37 0.8763 4.35 9662 5007 4655 39 0.8468 4.21 9841 5278 4564 41 0.8197 4.07 10015 5548 4467 43 0.7947 3.95 10183 5819 4364 45 0.7716 3.83 10347 6090 4257 47 0.7501 3.73 10505 6360 4145 49 0.7300 3.63 10660 6631 4029 51 0.7113 3.53 10810 6902 3908 53 0.6937 3.45 10957 7172 3784 55 0.6772 3.36 11100 7443 3657 57 0.6617 3.29 11239 7714 3526 59 0.6470 3.21 11376 7984 3391 61 0.6332 3.14 11509 8255 3254 Storage Volume Required = 5082 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles = 0.0069 ft/sec Design Release Rate= 2.26 cfs Minimum Area = 327 sf Criteria is met Basin Sizing (Pond 12) - Detention Water Depth = 1.5 ft Surface Area = 4508 sf (From AutoCAD) Volume = 5535 cf (From AutoCAD) Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.35 Low to Medium Density Residential 2.11 Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (cfs) (cf) (cf) (cf) 5 3.2185 2.38 713 140 574 7 2.5862 1.91 802 195 607 9 2.1964 1.62 876 251 625 11 1.9278 1.42 940 307 633 13 1.7295 1.28 996 363 633 15 1.5759 1.16 1047 419 629 17 1.4527 1.07 1094 474 620 19 1.3514 1.00 1138 530 608 21 1.2663 0.94 1178 586 592 23 1.1936 0.88 1216 642 575 25 1.1306 0.83 1252 698 555 27 1.0755 0.79 1287 753 533 29 1.0266 0.76 1319 809 510 31 0.9831 0.73 1350 865 485 33 0.9439 0.70 1380 921 459 35 0.9085 0.67 1409 977 432 37 0.8763 0.65 1437 1033 404 39 0.8468 0.63 1463 1088 375 41 0.8197 0.61 1489 1144 345 43 0.7947 0.59 1514 1200 314 45 0.7716 0.57 1539 1256 283 47 0.7501 0.55 1562 1312 251 49 0.7300 0.54 1585 1367 218 51 0.7113 0.53 1607 1423 184 53 0.6937 0.51 1629 1479 150 55 0.6772 0.50 1650 1535 116 57 0.6617 0.49 1671 1591 81 59 0.6470 0.48 1692 1646 45 61 0.6332 0.47 1711 1702 9 Storage Volume Required = 633 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles = 0.0069 ft/sec Design Release Rate= 0.47 cfs Minimum Area= 67 sf Criteria is met Basin Sizing (Pond 15) - Detention Water Depth = 1.5 ft Surface Area= 767 sf (From AutoCAD) Volume= 705 cf (From AutoCAD) Phase II and III Drainage Basin -16 The following calculations were used to determine the minimum required storage volume for storm water runoff. The volumes were calculated using the Rational Method, and the detention facilities were sized based on a 10-year 2-hour storm event. Pre-developed Conditions Area = 1.66 Acre C = 0.2 Open Land Calculate Time of Concentration (TJ Pre-developed Conditions: S = 1.90% C = 0.20 Open Land Conditions Assume: L =55 ft. (All overland flow) Using Equation in Section II-E-6 Tc= 10 min. (overland flow) Channel Flow Using Mannings Equation, n = 0.035, S=2.00%, calculate channel flow L = 0 ft R = 0.92 ft v= 5.68 ft/sec Tc= 0.00 min Total Tc= 10.OG `':'r min Calculate Pre-developed Storm Intensity at T, From Figure 1-3, using the 10 year event, I = 0.64TC-0.65 1 = 2.05 in/hr Calculate Pre-developed Peak Runoff Rate Q10 = ciA, using the above parameters. Q10= 0.68 cfs Calculate Developed Minimum Required Volume Storage For 10-Year Event C Value Description Area (Acres) 0.60 Right-of-way 1.66 C Value of 0.60 is weighted C value based on Hydrologic Analysis and Design, 2nd Edition, McCuen Developed Developed Pre-developed Storm Duration Intensity Runoff Rate Runoff Volume Release Volume Required Storage (Minutes) (in/hr) (cfs) (cf) (cf) (cf) 5 3.2185 3.21 962 204 757 7 2.5862 2.58 1082 286 796 9 2.1964 2.19 1181 368 814 11 1.9278 1.92 1267 449 818 13 1.7295 1.72 1344 531 812 15 1.5759 1.57 1413 613 800 17 1.4527 1.45 1476 695 781 19 1.3514 1.35 1534 776 758 21 1.2663 1.26 1589 858 731 23 1.1936 1.19 1641 940 701 25 1.1306 1.13 1689 1021 668 27 1.0755 1.07 1735 1103 632 29 1.0266 1.02 1779 1185 594 31 0.9831 0.98 1821 1267 555 33 0.9439 0.94 1862 1348 513 35 0.9085 0.90 1900 1430 470 37 0.8763 0.87 1938 1512 426 39 0.8468 0.84 1974 1593 380 41 0.8197 0.82 2008 1675 333 43 0.7947 0.79 2042 1757 285 45 0.7716 0.77 2075 1839 236 47 0.7501 0.75 2107 1920 187 49 0.7300 0.73 2138 2002 136 51 0.7113 0.71 2168 2084 84 53 0.6937 0.69 2197 2165 32 55 0.6772 0.67 2226 2247 -21 57 0.6617 0.66 2254 2329 -75 59 0.6470 0.64 2281 2411 -129 61 0.6332 0.63 2308 2492 -184 Storage Volume Required = 818 Calculate Minimum Surface Area For Storm Treatment Assume: 1. Non-flocculant particles 2. Settling velocity of 40 micron particles = 0.0069 ft/sec Design Release Rate= 0.68 cfs Minimum Area = 99 sf Criteria is met Basin Sizing (Pond 16) -Detention Water Depth = 1.5 ft Surface Area = 1193 sf (From AutoCAD) Volume= 837 cf (From AutoCAD) APPENDIX F OUTFALL STRUCTURE SIZING Meadow Creek Subdivisioin, Phases II and III Outfall Structure Sizing Used weir equation in Section II-2D of City of Bozeman Design Standards and Specifications Policy Q = CLHi.e L= Q/(CH'.$) Q values from Pre-developed runoff conditions Basin 5A Q = 0.47 cfs Basin 5B Q= 0.39 cfs Basin 6A Q = 1.07 cfs Basin 6B Q = 0.21 cfs Basin 7 Q = 1.77 cfs Basin 12 Q = 2.26 cfs Basin 15 Q= 0.47 cfs Basin 16 Q = 0.68 cfs H = 1.5 FT C = 3.33 FT Weir Lengths Pond 5A L= 0.076603 FT 0.9 Inches Pond 5B L= 0.063289 FT 0.8 Inches Pond 6A L= 0.174469 FT 2.1 Inches Pond 6B L= 0.03382 FT 0.4 Inches Pond 7 L= 0.289699 FT 3.5 Inches Pond 12 L= 0.368685 FT 4.4 Inches Pond 15 L= 0.076029 FT 0.9 Inches Pond 16 L= 0.11131 FT 1.3 Inches _ dr (OTN (D O > r N m N m O Vp T c; r 0 0 3 m c c o� rnrnoa) U cca r� co 1l- co tD y N T N r T [Ci N U v 0 to 0 t` to 0 - 00 0 0 (U T LO 0 h } V N r N T r i - m N � � tArOT d O M r 'w `V Cl) t` r- O M 1n N ■� U C u M Cl? CO CO M CO i V �? a ^ C CD 0 0 0 O C T T T r 5CD V to t() U') to to > W f�A Q M Q CO to t9 tt7 LO CD (D r t O -0 'O -0 'O U C c c c c O O O O O � a � aaa.