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HomeMy WebLinkAbout17 - Design Report - Professional Drive Apartments - Stormwater rta7 ENGINEERING IL I E Api4i I S CONSULTING PlR NGINEERING, INC DESIGN 204 NORTH 11thAVENUE,BOZEMAN,MT 59715 204 N 111"Ave. BOZEMAN,MT 59715 406-581-3319 www.g-a-i.net Storm Water Management Design Report Professional Drive Apartments Site Plan 766 & 776 Professional Drive Lot 4 Minor Subdivision 328 Bozeman, Montana February 2017 Prepared By: Genesis Engineering, Inc. GEI Project#: 1086.008 Prepared For: College Station LLC 1871 South 22nd Avenue, Suite 1 Bozeman, MT 59718 204 N. 11'"Ave., Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 1 of 7 Storm Water Management Design Report Table ofContents LProject Background.............................................................................................................. 3 l. Introduction..................................................................................................... ........................ 3 Z. Soil and Groundwater -------------.................................................... ............... 3 3. Land Use..................................................................................................... ............................... 3 N. Existing Conditions........................... ...................................................................................... 3 l. Drainage Basins and Peak Flows......... ................... .............................. 4 NL Proposed Drainage Plan and Post-Development Peak Flows........................................ 4 l. Major Drainage System................................................................................................ .......... 5 2. As-Built Storm Main .......................................................................................................... .... 5 3. Minor Drainage System ........................................................................................................ 6 4. Maintenance....... .............................................................................. ............................. ........ 7 IV. Conclusion................................................................................................................................ 7 List ofTables Table I. Estimated Pre-Development Peak Flows................................................. ............___............... 4 TaNeZ. Estimated Capacity of Existing Drainage Conveyance Structures........_....... ..................... 4 Table 3. Estimated Post-Development Peak Flows........................ ....................................................... 5 Table 4. Proposed Storm Detention Pond------------. -------------------- 5 Table 5. Proposed Drainage Conveyance Structures Capacities...................................... ....................5 Appendix A--Exhibitsand Calculations Grading and Drainage Exhibits Pre/Post Development Drainage Basin Flows Conveyance Structure Modeling List of References City of Bozeman Design Standards and Specifications Policy, March 2004,and all addenda. tdC1N�1~�I��,IN+0 a' ar�r�zaeir,,x ej?i�.4w�ufy tn�smaa� I. Project Background Introduction The Professional Drive Apartment Site consists of two separate,3-story, 12-unit, IVIT ' apartment buildings, 766&776 Professional { Drive, located in Lot 4,of Minor Subdivision 328. The existing lot covers approximately , 0.95 acres in Section 11,T2S, RSE, PMM in Bozeman, Montana. The property lies 1 immediately north of West College Street and approximately 0.25 miles east of Huffine Lane. This design report outlines the storm water � � �� analysis conducted for the site and describes � � F the storm water drainage and management facilities required for the Site by state and k � R local regulations. The storm water plan follows the design standards set forth by the City of Bozeman in Design Standards and .- Specifications Policy, March 2004 and three subsequent addenda. �: . �g4f Soil and Groundwater The NRCS Soil Survey identifies the major soil type on the site to be Turner Loam(457A). This soil belongs to hydrologic soil group B as it is comprised primarily of loam with moderately high saturated hydraulic Figure I: Vicinity map with Offsite Basin A. conductivity. A geotechnical investigation is being completed by a geotechnical engineer,and groundwater is expected to be greater than 72 inches deep. The presence of groundwater will not likely affect construction methods. However, based on this information any proposed ponds should likely have dry,vegetated pond bottoms. Land Use The pre-development land use on the site was a vacant lot. The land is currently zoned R-0 and the proposed use is for residential apartments. 11. Existing Conditions The Project Site lies immediately north of W.College Street and approximately 0.25 miles east of Huff ine Lane. There are no drainages in the near vicinity of the proposed project. The project's land slopes generally to the north at a grade of approximately 1.6%. The existing high point of the property is located on the south boundary line with the low point being on the northern boundary. The existing topographic features suggest a natural berm exists on the eastern boundary line keeping runoff from small storms from crossing the property 204 N. 11'h Ave., Bozeman,MT 59715 Cell:(406)581-3319 www.o-e-i.net Page 3 of 7 5045P line. The existing topography of the overall site conveys runoff to Huffine Lane where it then runs northeast to join East Catron Creek. Drainage Basins and Pre-development Peak Flows Genesis identified the major contributing drainage basin from lands offsite and other onsite drainage basins as shown on exhibit GD1 found in Appendix A. The OS-A drainage basin stretches from the outfall on the subject property's north line for approximately 7,000 feet to the south, ending in the vicinity of Stucky Road. Estimates of runoff and their respective calculations for the more local existing drainage basins were completed using the Modified Rational Method. Our offsite basin model uses a pre-development runoff coefficient of C=0.20 which does not necessarily represent the typical ground cover we see today. The local basin also use a pre-development runoff coefficient of C=0.20. Genesis looked at storm return intervals such as the 10-year, 25-year and 100-yr during the analysis of the existing storm water conveyance structures in or near the site. A summary of estimated pre-development peak runoff rates as well as existing drainage conveyance structure capacities can be found in Tables 1 and 2. Detailed calculations are available in Appendix A. Table 1. Estimated Pre-Development Peak Flows(see GD-1) Sub Area Description Area Tc Q10 Q25 Q100 (acres) (min) (cfs) (cfs) (cfs) OS-A Offsite Basin 41.4 70 4.8 5.9 7.5 A Onsite Basin 1.0 10 0A 0.5 0.7 Table 2. Existing Drainage Conveyance Structure Capacities Description Depth Slope Contrib. Q25pre Struct.Cap. Passes (ft) N Areas (cfs) (cfs) 25-YR StreetFlow—Professional 0.35 1.9 OS-A 5.9 85.8 Y Drive Existing Storm Inlet 0.5 SUMP %of 3.0 5.0 Y @ North End of Professional Drive. OS-A Existing Storm Inlet 0.5 SUMP %of 3.0 5.0 Y @ North End of Professional Drive. OS-A III. Proposed Drainage Plan and Estimated Post-Development Peak Flows The proposed drainage plan shall build off of the existing or natural drainage system in place. Genesis' drainage plan really consists of two separate drainage systems. First,the major drainage system or backbone is designed to have a much higher conveyance capacity and shall convey the excess runoff from the 100-year storm without inundating any building structures. Secondly,the minor drainage system fits within the major drainage system and feeds into it. The minor drainage system(s)are designed to accommodate moderate and relatively frequent storm events without inconveniencing the public, The minor system is comprised of the streets, inlets,and swales designed to convey runoff from the 25-year event,and the detention pond designed to attenuate the 10-year storm event. Table 3 presents a summary of the expected post-development peak flow rates passing through the proposed project. 204 N. 111"Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 4 of 7 (%"P Table 3. Estimated Post-Development Peak Flows(see GD-1) Sub Area Description Area C Tc Q30 Q25 Q100 (acres) (min) (cfs) (cfs) (cfs) OS-A Offsite Basin-SCS TR-20 41.4 0.35 70 8.4 10.2 13.2 A Onsite Rational 1.0 0.60 10 1.3 1.5 2.0 Major Drainage System The major drainage system in the area is comprised of Catron Stream to the east of the subject parcel and the north-south street: Professional Drive.Catron Stream is far enough east that it appears to have no significant impact on the subject parcel. Professional Drive has adequate street conveyance capacity to convey the 100- yr event through the subdivision without inundating the first floor of the proposed structures. It is noted that the first floor elevations are greater than 1.0 foot above the curb and gutter at the center of each proposed building on Professional Drive. Based on the proposed first floor elevations and slope of the existing street to the north,we do not anticipate the structures being inundated by storm events up to and including the 100-yr event. Minor Drainage System The proposed minor drainage system for the Professional Drive Apartments includes two interior parking lots with sheet flow directed into the curb outlets located at the northeast corner of each of the proposed parking lots. A single Swale, beginning at the south property boundary, conveys runoff to the north into the proposed stormwater detention pond. The detention pond is sized to retain the 10-year storm flows as required.The outfall of the proposed detention pond is into the east curb and gutter of Professional Drive through a City of Bozeman standard sidewalk chase. Once the 25-year event leaves the site,it will flow down Professional Drive and be collected by existing storm inlets on the north end of Professional Drive. The catch curb and gutter of each of the parking lots will convey an estimated 4.5 cfs before inundating the adjacent sidewalk which is many times greater than the 100-year flow rate contributed by impervious area on site-half of Basin A. The proposed Swale conveying runoff to the detention pond has a capacity of 10-12 cfs which is many times greater than the runoff contributed by the site's local Basin A during the 25-Yr Storm.The pipe in the middle of the Swale is a 15"A-2000 pipe that conveys the runoff from half of Basin A,has a capacity of 7.3 cfs,which is many times greater than the 100-year storm.The proposed storm pond with all intended areas contributing,and using a future developed ground cover condition of 0.6. Table 4. Detention Pond Volume(See GD-2) Pond Type Depth Contributing Q10 PST Req.Vol. Avail.Vol. Retains Subarea (cfs) (cft) (cft) Design Storm 1 Detention NE Corner A 1.3 475 700 Y Table S. Proposed Drainage Conveyance Structure Capacities(See GD-2) Description Contributing Depth Slope Q10PST Q25PST Q10OPST Qcap Passes Subareas (ft) N (cfs) (cfs) (cft) (cfs) Design Storm Street Flow-Professional Drive OS-A 0.3 2.0 9.7 11.7 15.2 85.8 Y &A Site-Catch Curb and Gutter Y.of A 0.3 0.5 0.6 0.8 1.0 4.5 Y Site-Swale A 1.0 0.8 1.3 1.5 2.0 10-12 Y Swale Pipe '/:of A 1.0 0.6 0.6 0.8 1.0 7.3 Y 204 N. 11`"Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 5 of 7 (%"n Maintenance Regular maintenance of storm water facilities is necessary for proper functioning of the drainage system. In general, regular mowing of any grass swales and storage ponds and unclogging of inlets and outlet works will be required to prevent standing water,clogging,and the growth of weeds and wetland plants. More substantial maintenance,such as sediment removal with heavy equipment, may be required in coming decades to restore detention pond volume. All maintenance and repair should be prioritized and scheduled in advance. Inlets&pipes should be visually inspected yearly. Typical maintenance items include removing obstructions,cleaning and flushing pipes, mowing grass and weeds,tree maintenance to prevent limbs from falling and blocking swales,and establishing groundcover on bare ground. IV. Conclusion Storm water analysis and calculations indicate that the proposed storm water management plan for the proposed site plan is adequate to safely convey the 10-year, 25-year, and 100-year storm events while satisfying state and local regulations for peak attenuation and stormwater storage. No hazardous backwater affects from downstream structures have been observed to affect the proposed site plan. The project as planned and described within this report will not have any significant adverse effects on any neighboring properties. Furthermore,the proposed first floor elevation for the proposed structure is above the estimated 100-yr Base flood Elevation as estimated by Genesis Engineering. H:\1086\008\DOCS\DESIGN\Storm\Report\StormwaterDR-working example.doc `> 204 N. 11`h Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i,net Page 6 of 7 �z N�IN��Rth1Cs Y3$l�x4wsf CfC 'Aaudail{d)C'an:Yni Appendix A Exhibits & Calculations 204 N. 11"Ave.,Bozeman,MT 59715 Cell:(406)581-3319 www.q-e-i.net Page 7 of 7 350'TO EAST CATRON STREAM / x x � / x — 0e x - y x x x x — x _ ) BASIN A x>�xxx>xxxxx>e—�xxx T J _ — �� I I 1.0 ACRES mcn cn I I I IDo I m GO Lxx�><X><>< J / / ® / GRAPHIC SCALE / (IN FEET) ^ — 1 neh= 20 f, 7� I 11"X17':1"=45ft PROFESSIONAL DRIVE o 1 APROXIMATE r ^ LOCATION OF EAST CATRON STREAM ... + -.NZ T�0+ 7 g v BASIN A ' �,. . i► 1 AACRES x r * ! BASIN OS-A i } ' * 41.4 ACRES VENUE m r m G) • 25o GRAPHIC SCALE 250 U) (IN FEET) m fll 1 Inch= 250 SL 1 11'X1T:1'=500 ft L VERIFY SCALE REVISIONS DRAWN BY:JAH PROJECT NUMBER THESE PRINTS MAY BE NO. DESCRIPTION DATE BY CHK'D.BY:JRM PROFESSIONAL DRIVE APARTMENTS 10B6.008 REDUCED.LINE BELOW SHEET NUMBER MEASURES ONE INCH ON ORIGINAL DRAWING. _ Erlgir wring APPR.BY:JRM BOZEMAN MT NESISLDnsWling 204 N.1111 Ave. Design Bozeman,MT 59715 DATE:02/20I2017 DRAWING NUMBER MOD-SCALE ACCORDINGLY NGINEERING, INC Fi e..... nl.g B Phone;(406)581-3319 O.A.REVIEW GD-1 v: BASIN DEFINITION H:\1056100B1ACAD\EXHIBITS\BASINS.dwg Plolled by joel hom on— 7h[Ql�irtnrn o u;1nv furtrfat�0 dmmifmrnf coPmlceracENEsls ENGINEERING.wc.zon DATE: NOTES: 1. SPOT ELEVATIONS SHOWN ARE 48XX.XX' 2. CATCH CURB:TBC=FLAG+0.38' 3. FSW=FRONT OF SIDEWALK 4. BSW=BACK OF SIDEWALK I 5. SIDEWALK IS 0.5'ABOVE ADJACENT ASPHALT 6. SPILL CURB:TBC=FLAG+0.55' 7. LAYDOWN CURB:TBC=FLAG INSTALL 15"A-2000 PIPE,L=45' I I 8. ALL CURB TO BE PER CURB&GUTTER DETAIL,SHEET C-3 PROPOSED STORMWATER INV INA810.00' / 9. IT IS THE CONTRACTOR'S RESPONSIBILITY TO ASSURE DETENTION POND INV OUT: -1' BOT ELEV=4809.25' (TO BE EMBEDDEEDD 4') EXISTING BARBED PROPOSED SWALE i lb1 WIRE FENCE $,.o=1.0%WHEELCHAIR ACCESSIBLE MEET DA REQUIREMENTS.RAMPS AND SIDEWALKS AVAILgBLE VOLUME=700 CFT SEE DETAIL SHEET C-3 10.TBC=TOP BACK CURB, BSW=BACK SIDEWALK REQUIRED VOLUME=475 CFT i \ 11.CONTRACTOR TO ASSURE LESS THAN 2%SLOPE IN GRAPHICAL PROPERTY ___ WHEELCHAIR ACCESSIBLE PARKING STALLS. ` -- —`— - TRI. CURB CUTo - 12. CONTRACTOR TO ASSURE POSITIVE DRAINAGE 2'CURB CUT AWAY FROM THE BUILDING. -jl — — �ac� - — _ - — ,! - 00 13.ALL STORM STRUCTURES SHALL MEET COB — - y SECTION 02720 STANDARDS. 5 1 09. - TBC 00' — — ty 7s' ti:oo' / I z \ f " \TBC 1 y0 __� 00' \ BS TBC 13:40'� 1'L 1 f 7 i14.63' I I m 11. — EXITING CHAIN - h TBC \I (LINK FENCE - --- -� — — .` / I 14.25' I I 1 I ( I `. -,.L• TBC BSWly 13.43' I I II / 13.82' 1 A URE 2.0%MAX- I INSTALL,'LANDSCAPE %1 , z% ^. TS3 / \1.5% B.W S'rOA�amLP E,A CRO SS H. RETAINING WALL 11.0' 1353 L BSWTBC 13.56' 11.40' 11.02' TB 1.5%PER DETAIL SHEET C-3 5 t 134C6BSW 1 12' ASSURE2,0 MAX 1400' BSW /L�JII I t\I _,-.•�,-,'I I mUM SLOPE AC SSH.C. TBC STALL&AIL 11 I I BSW 1' - y / 776 PROFESSIONAL DRIVE SEE CROSS SEyTION A-A ` 766 PROFESSIONAL DRIVE 11.16 "' T It PROPOSED BUILDING zx \ I \� O I HEET C-3 j ` PROPOSED BUILDING BSW y'S 11h1 " / FFE=4814.00' NVS�' I, I I FFE=48,1.50' 11.50, tP TBC W i� LI I m 1•. m A M A z% ,1.46 \ `�1.5% I � qh i I II I I cn / Cp POND OUTLET / STROCTURE I.E.=4809.26 TOP STRUCTURE=4809.75 dEE DETAIL SHEET C-3 TBC/ I I � � TB•� -- _ - ^v / 15/T3'O / / /� / / BENCHMARKCPpt y I BSW TBC H.P. / 11.65, m, / 5!8'REBAR ` — _ Mrx T 11.90' __ /- 7 / ELEV=4808.44' 7 — I — — — — — — — — I ..nx......................."..,.,.,...,.,.,.,...K,.,.-- K„KH,.,.-,.,..«,.,.,<,.,.,.,.,...,.,.,.,.,.H,<�,�K -- ! _ TB — — TBC < j - /�/ \ — — — — 1'YJ— .— p g —- 12.6.i`— �pER'(Y / BSW 77 1�0' _ \..\ 14.13' t \ / / H\C N/ / / _ BENCHMARK 2 _ \ SIDEWALK CHASE ` N I �,r , �o. . 10.7r So' /l _ >.3 SW 0 GµPP L i / 5l8"REBAR� 14808:98' 00' ,� ELEV=489, BSW BSW _ _s _ % _ _ _ I j Nz - i i / / — — — 09.�3'=---\ - 1� _=i L. — —- '8S z — — — 11.58' — — — y/ --__ 4,31' BZ��� /f - - -T - - - �SwATO ��- _ _ - - -_-r - - - - -i- - - - - - - - _ - - - - -r // I / CHASE-09:50'- / Z T = PROFESSIONAL DRIVE I \\ INSTALL 11,5'OF SIDEWALK CHASE (37 TBC TO TBC) PER DETAIL SHEET C-3 \ \ INV AT FLOW LINE OF CURB=4808JV \ \ \ -- - - - - - - - - -- - - - - - - _ - \ \ \ I L- — — — — — — — — — — — — — — — ----- — — — — — — --- — — — — — — —� — — — — — — — — — — — — -- — — — — r — \ \ Is GRAPHIC SCALE - - - - - - - - - - \ q 7s s �I IT - - - TI- - - - - - - - - - - - - - - - - - - - - - - T 7 (IN FEET) I I I I I I I 1VX17";1"=30ft \` VERIFY SCALE REVISIONS i- DRAWN BY.JAH PROJECT NUMBER -ESE W--E NO. DESCRIPTION DATE BY CHCO.BY:JRM PROFESSIONAL DRIVE APARTMENTS 10e6.666 REDUCED.UNEBaL ME URESONEIWHON SITE PLAN SUBMITTAL owGiNU DRwvnnc. �( Figfnaering APPR.BY: BOZEMAN MT SHEET NUMBER ,11! Consulting 204 N.111h Ave. Desiyn Bozeman,MT 59715 DATE:02/2017 DRAWING NUMBER MODIFYSCr1LEA—MNMY INEERING, INC Plonnmg Phone:(406)581-3319 D.A.REVIEW GRADING&DRAINAGE PLAN NG BY: C_2 H:\1086\OOMCAD\SHEETS\SHEET-C2-GRADING.dwg Plotled by chdstopher waste on 2120/20172:43 PM rt47t innin o 4'Siw.Sfunfarfa OMMifmtaf C0PYRIGM0GENESISENGINEEMNG,INC.9n7 DATE: GEI#: 1086.008 DATE: 2/10/2017 ENGINEER: Chris Wasia BASIN A- 10yr MODIFIED RATIONAL METHOD NGINEERING, INC Qp=CIA 2L1�-*!,t;ifw�.ti _ f3��. �u,d-�`+J?•5 z. s 33t<3 PRE-DEVELOPMENT RAINFALL FREQ= 10 YR(DURATION=1) 1=A" (Tc/60).g (CITY OF BOZEMAN) BASIN AREA PRE= 1 AC STORM EVENT STORM i COEFF INTENSITY YR A _ B IN HR PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1.05 5 0.52 0.64 1.64 PRE-DEV C= 0.20 10 0.64 0.66 2.09 25 0.78 0.64 2.46 STORM A= 0.64 50 0.92 0.66 3.00 B= 0.66 100 1.01 0.67 3.35 STORM INTENSITY= 2.09 IN/HR PRE-DEV Qp= 0.42 CFS POST-DEVELOPMENT BASIN AREA PRE= 1 AC POST-DEV Tc= 10.0 MIN POST-DEV C= 0.6 STORM INTENSITY= 2.09 IN/HR POST-DEV Qp= 1.25 CFS H:\1086\008\DOGS\DESIGN\Storm\Basin A-10yr 1 OF 1 PRINTED: 2/20/2017 GEI#: 1086.008 DATE: 2/10/2017 ENGINEER: Chris Wasia BASIN A - 25yr ��� � � w� N E 4105'�1 S MODIFIED RATIONAL METHOD ti a " NGINEERING5 IC Qp=CIA 17ef fA,!. t`C t rN.M IT?!5 ; 511..;Si`.'.3 PRE—DEVELOPMENT RAINFALL FREQ= 25 YR(DURATION=1) i=A*(Tc/60) ° (CITY OF BOZEMAN) BASIN AREA PRE= 1 AC STORM EVENT STORM i COEFF INTENSITY YR A B IN HR PRE-DEV Tc= 10.0 MIN 2 0.36 0.6 1.05 5 0.52 0.64 1.64 PRE-DEV C= 0.20 10 0.64 0.66 2.09 25 0.78 0.64 2.46 STORM A= 0.78 50 0.92 0.66 3.00 B= 0.64 100 1.01 0.67 3.35 STORM INTENSITY= 2.46 IN/HR PRE-DEV Qp= 0.49 CFS POST—DEVELOPMENT BASIN AREA PRE= 1 AC POST-DEVTc= 10.0 MIN POST-DEV C= 0.6 STORM INTENSITY= 2.46 IN/HR POST-DEV Qp= 1.47 CFS H:\1086\008\DOCS\DESIGN\Storm\Basin A-25yr 1 OF 1 PRINTED: 2/20/2017 GEI#: 1086.008 DATE: 2/10/2017 ENGINEER: Chris Wasia � BASIN A- 100yr N EA'So' I S MODIFIED RATIONAL METHOD . NGINEE I Gt INC Qp=CiA iG/'N ...n.A DO i .MT'4911 t. 4 5 Fa,t PRE-DEVELOPMENT RAINFALL FREQ= 100 YR(DURATION=1) i=A*(Tc/60)_B (CITY OF BOZEMAN) BASIN AREA PRE= 1 AC STORM EVENT STORM i COEFF _INTENSITY YR A_ B (IN HR PRE-DEVTc= 10.0 MIN 2 0.36 0.6 1.05 5 0.52 0.64 1.64 PRE-DEV C= 0.20 10 0.64 0.66 2.09 25 0.78 0.64 2.46 STORM A= 1.01 50 0.92 0.66 3.00 B= 0.67 100 1.01 0.67 3.35 STORM INTENSITY= 3.35 IN/HR PRE-DEV Qp= 0.67 CFS POST-DEVELOPMENT BASIN AREA PRE= 1 AC POST-DEVTc= 10.0 MIN POST-DEV C= 0.6 STORM INTENSITY= 3.35 IN/HR POST-DEV Qp= 2.01 CFS H:\1086\008\DOGS\DESIGN\Storm\Basin A-100yr 1 OF 1 PRINTED: 2/20/2017 GEI#: 1086.008 DATE: 2/10/2017 ENGINEER: Chris Wasia BASIN OS-A - 10yr NESIS MODIFIED RATIONAL METHOD NGINEERING, INC Qp=CIA 2.C7.�'{.':f i{s Ali.. n JlGI.�.AY.,.iT ),'tom p 3 ��➢;�:1"',� PRE-DEVELOPMENT RAINFALL FREQ= 10 YR(DURATION=1) i=A*(Tc/60).a (CITY OF BOZEMAN) BASIN AREA PRE= 41.4 AC STORM EVENT STORM i COEFF INTENSITY YR A B IN HR PRE-DEVTc= 70.0 MIN 2 0.36 0.6 0.33 5 0.52 0.64 0.47 PRE-DEV C= 0.20 10 0.64 0.66 0.58 25 0.78 0.64 0.71 STORM A= 0.64 50 0.92 0.66 0.83 B= 0.66 100 1.01 0.67 0.91 STORM INTENSITY= 0.58 IN/HR PRE-DEV Qp= 4.79 CFS POST-DEVELOPMENT BASIN AREA PRE= 41.4 AC POST-DEV Tc= 70.0 MIN POST-DEV C= 0.35 STORM INTENSITY= 0.58 IN/HR POST-DEV Qp= 8.38 CFS H:\1086\008\DOGS\DESIGN\Storm\Basin OSA-10yr 1 OF 1 PRINTED: 2/20/2017 GEI#: 1086.008 DATE: 2/10/2017 ENGINEER: Chris Wasia BASIN OS-A- 25yr NESIS MODIFIED RATIONAL METHOD NGINEERING, INC Qp=CiA 20.ra razk,n,z PRE-DEVELOPMENT RAINFALL FREQ= 25 YR(DURATION=1) i=A*(Tc/60)-B (CITY OF BOZEMAN) BASIN AREA PRE= 41.4 AC STORM EVENT STORM 1 COEFF I INTENSITY YR A B IN HR PRE-DEVTc= 70.0 MIN 2 0.36 0.6 0.33 5 0.52 0.64 0.47 PRE-DEV C= 0.20 10 0.64 0.66 0.58 25 0.78 0.64 0.71 STORM A= 0.78 50 0.92 0.66 0.83 B= 0.64 1 100 1.01 0.67 0.91 STORM INTENSITY= 0.71 IN/HR PRE-DEV Qp= 5.85 CFS POST-DEVELOPMENT BASIN AREA PRE= 41.4 AC POST-DEVTc= 70.0 MIN POST-DEV C= 0.35 STORM INTENSITY= 0.71 IN/HR POST-DEV Qp= 10.24 CFS H:\1086\008\DOGS\DESIGN\Storm\Basin OSA-25yr 1 OF 1 PRINTED: 2/20/2017 GEI#: 1086.008 DATE: 2/10/2017 ENGINEER: Chris Wasia BASIN OS-A - 100yr � MODIFIED RATIONAL METHOD NGINEERING; INC Qp=CIA 2 0;P7 . [1(td ..v.kIAT 9 :..> <. F PRE-DEVELOPMENT RAINFALL FREQ= 100 YR(DURATION=1) 1=A*(Tc/60)_B (CITY OF BOZEMAN) BASIN AREA PRE= 41.4 AC STORM EVENT STORM i COEFF INTENSITY (YR) A B (IN/HR PRE-DEV Tc= 70.0 MIN 2 0.36 0.6 0.33 5 0.52 0.64 0.47 PRE-DEV C= 0.20 10 0.64 0.66 0.58 25 0.78 0.64 0.71 STORM A= 1.01 50 0.92 0.66 0.83 B= 0.67 100 1.01 0.67 0.91 STORM INTENSITY= 0.91 IN/HR PRE-DEV Qp= 7.54 CFS POST-DEVELOPMENT BASIN AREA PRE= 41.4 AC POST-DEVTc= 70.0 MIN POST-DEV C= 0.35 STORM INTENSITY= 0.91 IN/HR POST-DEV Qp= 13.20 CFS H:\1086\008\DOGS\DESIGN\Storm\Basin OSA-100yr 1 OF 1 PRINTED: 2/20/2017 GERI: 1086.008 DATE: 2/9/2017 ENGINEER: Chris Wasia DET-Pond-A-10yr MODIFIED RATIONAL METHOD �� " WEER[} , INC Qp=CIA .."33.'.5. PRE-DEVELOPMENT RAINFALL FREQ= 10 YR(DURATION=1) i=A*(Tc/60).g (CITY OF BOZEMAN) BASIN AREA PRE= 1 AC STORM EVENT STORM i COEFF INTENSITY YR A_ B IN HR PRE-DEVTc= 10.0 MIN 2 0.36 0.6 1.05 5 0.52 0.64 1.64 PRE-DEV C= 0.20 10 0.64 0.66 2.09 25 0.78 0.64 2.46 STORM A= 0.64 50 0.92 0.66 3.00 B= 0.66 100 1.01 0.67 3.35 STORM INTENSITY= 2.09 IN/HR PRE-DEV Qp= 0.42 CFS POST-DEVELOPMENT POND VOLUME: CONSTAELEASEi (CF) BASIN AREA PRE= 1 AC 34S.Z$ POST-DEV Tc= 10.0 MIN TRIANGLE RELEASE DETENTION (CF), POST-DEV C= 0.6 591.04 STORM INTENSITY= 2.09 IN/HR AVERAGE VOLUME i (CF) POST-DEV Qp= 1.25 CFS 468,41` OUTLET STRUCTURE DESIGN RETENTION#. i. (CF) POND: DET-Pond-A-10yr '177110 REQUIRED VOL= 468.41 CF (AVG.B/W CONST.&TRIANGLE RELEASE) DIAMETER= 6.00 IN LENGTH OF PIPE= 10.00 FT QPRE= 0.42 CFS HEAD WATER= 0.50 FT AREA= N/A SF N= 0.012 ORIFICE= N/A IN Ke= 0.50 ORIFICE FLOW= N/A CFS SLOPE OF PIPE= 0.005 FT/FT FLOW OUT= 0.24 CFS **FLOW GOOD AVE SURF AREA= 691.57 SF H:\1086\008\DOGS\DESIGN\Storm\Pond-A 1 OF 2 PRINTED: 2/20/2017 DET-Pond-A-10yr POND VOLUME CALC'S OUTLET STRUCUTRE CALC'S Triangle Release Constant Release SLOPE OF ENERGY ORIFICE DURATION INTENSITY Qp POND VOLUME POND VOLUME PIPE FLOW OUT (MIN) (IN/HR) (CFS) (CF) (CF) (FT/FT) (CFS) (CFS) 9.50 2.16 1.30 494.42 330.85 0.000 0.000 0.419 10.50 2.02 1.21 507.46 336.88 0.001 0.107 11,50 1.90 1.14 518.94 341.17 0.002 0.151 12.50 1.80 1.08 529.08 343.96 0.003 0.185 13.50 1.71 1.03 538.06 34S.45 0.004 0.214 14.50 1.63 0.98 546.00 345.78 0.005 0.239 15.50 1.56 0.94 553.03 345.09 0.006 0.262 16.50 1.50 0.90 559.25 343.48 0.007 0.283 17.50 1.44 0.87 564.73 341.03 0.008 0.303 18.50 1.39 0.83 569.55 337.83 0.009 0.321 1950 1.34 0.81 573.75 333.94 0.010 0.338 20.50 1.30 0.78 577.40 329.42 0.011 0.355 21.50 1.26 0.76 580.54 324.31 0.012 0.371 22.50 1.22 0.73 583.20 318.66 0.013 0.386 23.50 1.19 0.71 585.42 312.50 0.014 0.400 24.50 1.16 0.69 587.23 305.88 0.015 0,414 2S.50 1.13 0.68 588.67 298.82 0.016 0.428 26.50 1.10 0.66 589.74 291.35 0.017 0.441 27.50 1.07 0.64 590.48 283.50 0.018 0.454 28.50 1.05 0.63 590.91 275.28 0.019 0.466 29.50 1,02 0.61 591.04 266.72 0.020 0.479 30.50 1.00 0.60 590.89 257.84 0.021 0.490 31.50 0.98 0.59 590.47 248.64 0.022 0.502 32.50 0.96 0.58 589.81 239.16 0.023 0.513 33.50 0.94 0.56 588.90 229.40 0.024 0.524 34.50 0.92 0.55 587.77 219.38 0.025 0.535 35.50 0.90 0.54 586.42 209.10 0.026 0.546 36.50 0.89 0.53 584.87 198.58 0.027 0.556 37.50 0.87 0.52 583,12 187.84 0.028 0.566 38.50 0.86 0.51 581.18 176.87 0.029 0.576 39.50 0.84 0.51 579.06 165.69 0.030 0.586 40.50 0.83 0.50 576.77 154.31 0.031 0.596 41.50 0.82 0.49 574.31 142.74 0.032 0.605 42.50 0.80 0.48 571.70 130.98 0.033 0.615 43.50 0.79 0.47 568.93 119.04 0.034 0.624 44.50 0.78 0.47 566.01 106.93 0.035 0.633 45.50 0.77 0.46 562.95 94.6S 0.036 0.642 46.50 0.76 0.45 559.76 82.21 0.037 0.651 47.50 0.75 0.45 556.44 69.61 0.038 0.660 48.50 0.74 0.44 552.98 56.86 0.039 0.668 49.50 0.73 0.44 549.41 43.97 0.040 0.677 H:\1086\008\DOCS\DESIGN\Storm\Pond-A 2 OF 2 PRINTED: 2/20/2017 Project Professional Drive r—\ BE|#: 1080.008 Area Area C Basin A Impervious 24218.10 0.555971074 0.9 Gn@ae 18307.40 0.420280073 0.2 Total area 42525.50 � .~~ Worksheet for Catch Gutter - Parking Lot Project Description Solve For Discharge Input Data Channel Slope 0.00500 ft/ft Gutter Width 1.50 ft Gutter Cross Slope 0.06 ft/ft Road Cross Slope 0.01 ft/ft Spread 17.00 ft Roughness Coefficient 0.013 Results Discharge 4.47 ft3/s Flow Area 1.93 ft2 Depth 0.30 ft Gutter Depression 0.07 ft Velocity 2.31 ft/s Bentley Systems,Inc. Haestad Methods ScIbik isP6h>Waster V8i(SELECTseries 1) (08.11.01.03] 2/20/2017 10:47:32 AM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1 Worksheet for Swale Capacity Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.035 Channel Slope 0.00750 ft/ft Normal Depth 1.00 ft Left Side Slope 4.00 ft/ft(H:V) Right Side Slope 4.00 ft/ft(H:V) Bottom Width 1.00 ft Results Discharge 12.20 ft'/s Flow Area 5.00 ftZ Wetted Perimeter 9.25 ft Hydraulic Radius 0.54 ft Top Width 9.00 ft Critical Depth 0.78 ft Critical Slope 0.02422 ft/ft Velocity 2.44 ft/s Velocity Head 0.09 ft Specific Energy 1.09 ft Froude Number 0.58 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF°Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 1.00 ft Critical Depth 0.78 ft Channel Slope 0.00750 fUft Bentley Systems,Inc. Haestad Methods SdAakkW)C9kbmMaster V8i(SELECTseries 1) [08.11,01.03] 2/20/2017 3:45:53 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 2 Worksheet for Swale Capacity GVF Output Data Critical Slope 0.02422 ft/ft Bentley Systems,Inc. Haestad Methods SdbeliklelPl M Master V8i(SELECTseries 1) [08.11.01.03] 2/20/2017 3:45:53 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 2 of 2 Worksheet for Swale Pipe Project description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.009 Channel Slope 0.00640 fUft Normal Depth 1.00 ft Diameter 1.25 ft Results Discharge 7.30 ft'/s Flow Area 1.05 ft2 Wetted Perimeter 2.77 ft Hydraulic Radius 0.38 ft Top Width 1.00 ft Critical Depth 1.08 ft Percent Full 80.0 % Critical Slope 0.00564 ft/ft Velocity 6.93 ft/s Velocity Head 0.75 ft Specific Energy 1.75 ft Froude Number 1.19 Maximum Discharge 8.03 ft'/s Discharge Full 7.46 W/s Slope Full 0.00611 ft/ft Flow Type SuperCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 80.00 % Downstream Velocity Infinity ft/s Bentley Systems,Inc. Haestad Methods Sd3w*We C*kb&&Iaster V8i(SELECTseries 1) [08.11.01.03] 2/20/2017 1:35:04 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 2 Worksheet for Swale Pipe GVF Output Data Upstream Velocity Infinity ft/s Normal Depth 1.00 ft Critical Depth 1.08 ft Channel Slope 0.00640 ft/ft Critical Slope 0.00564 ft/ft Bentley Systems,Inc. Haestad Methods SdbsbWgCRdwMaster V8i(SELECTseries 1) [08.11.01.03] 2/20/2017 1:35:04 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 2 of 2 Cross Section for Gutter - Professional Dr Project Description Solve For Discharge Input Data Channel Slope 0,02000 ft/ft Discharge 42.91 ft3/s Gutter Width 1.50 ft Gutter Cross Slope 0.06 ft/ft Road Cross Slope 0.03 ft/ft Spread 18.50 ft Roughness Coefficient 0.013 Cross Section Image 10.Su ft V 1.1 H: 1 Bentley Systems,Inc. Haestad Methods SclAAM ICEOWaster V8i(SELECTseries 1) [08.11.01.031 2/20/2017 3:44:48 PM 27 Siemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-755-1666 Page 1 of 1