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HomeMy WebLinkAboutDrainage Reports - 10/25/1995Final Approved Report D2s a..o Final Storm Drainage Report for ARENA OFFICE PARK P.U.D. X�« . August 1995 Stewart & Associates Consulting Engineers and Surveyors 103 South Meldrum Street Fort Collins, Colorado 80521 (970) 482-9331 z� ' STEWART&kSSOCIATES Consulting Engineers and Surveyors 8-10-95 To: Basil Hamdan Storm Drainage Utility City of Fort Collins ' Re: Arena Office Park P.U.D. ' Dear Basil, ' Attached is the "Final Storm Drainage Report" for the aforementioned project for your review and approval. The project is a Retail/Office complex for Foothills Land Ltd. This project ' will not include onsite detention for the development area of 2.70 acres. In 1980 an agreement was reached with the Warren Lake Co. allowing for storm runoff to go directly into Warren Lake. Existing facilities have been reviewed and do not present any capacity concerns. All hydrologic and hydraulic design in this report meet the City of Fort Collins, Storm Drainage Design Criteria and Construction Standards, (1984). Should question or concerns arise regarding this project during your review, please do not hesitate in contacting our office. Respectfully, a . Richard A. Rutherford, P.E., L.S. # 5028 James H. Stewart and Associates, Inc. 103 S. Meldrum Street P.O. Box 429 Ft. Collins, CO 80522 303/482-9331 Fax 303/482-9382 5028 !�/C/�t//TY ,�l%�P �C.gCE / ��/O� ' Final Storm Drainage Report for ' Arena Office Park P.U.D. GENERAL SITE The following is the final drainage report for the Arena Office Park P.U.D. The P.U.D. contains ' 2.70 acres and is a part of Lot 3, Strachan Subdivision, Third Filing, which is in the Southwest 1/4 of Section 25, Township 7 North, Range 69 West of the 6th P.M. The P.U.D. is in the Foothills Drainage ' Basin. The site is bounded on the west by J.F.K. Parkway, on the north by the Northwest Bank Fort Collins -South property, on the northeast by the Healthworks health club and its parking lot, and on the ' south by the Marriott Hotel. The site slopes from northwest to southeast at an approximate slope of 4.5 % on the northeast end and by an approximate slope of 2.8% on the southwest end of the property. The site has an existing good groundcover of native grasses, weeds and blue grass. There has been some fill dirt piled on a small area at the northwest corner of the site. ' It is proposed to construct five office buildings in the P.U.D. along with parking facilities for the buildings. Building No. 1 in the northeast corner of the site will be started as soon as the development plans are approved by the City of Fort Collins. The other buildings will be constructed after contracts ' are completed with the tenants. ' HYDROLOGY ' The drainage from the Strachan Subdivision, Third Filing, was designed in November 1980. At that date, Mitchell and Company negotiated an agreement with the Warren Lake Company to provide ' storm water detention in Warren Lake. All of the Arena Office Park P.U.D. drains to Warren Lake and, therefore, is not required to have onsite detention. A storm drainage system was built in 1981 and extended when the Marriott Hotel was constructed. All of the storm water runoff from this site will drain to the existing inlets and in the existing storm drain system and in a swale above the storm drain. It is imperative that there be capacity to carry the runoff from this site in a swale around the northwesterly end of the Marriott Hotel in case the inlet grates become plugged. Buildings 4 and 5 and their parking area will drain to a new area inlet that will discharge through a new 15" storm drain to an existing curb ' inlet on the east side of John F. Kennedy Parkway. u ' Arena Office Park P.U.D. Page 2 t The site has been divided into five developed sub -basins. Sub -basin I is the east half of J.F.K. Parkway which is the same basin historically and after the P.U.D. is developed. Sub -basin 2 encompasses Building 1 and the parking area to the southeast of the building. Sub -basin 2 drains to the existing area inlet. Sub -basin 3 encompasses Building 2 and the parking lot between Buildings 1 and 2, and the runoff will discharge into the existing area inlet near the southwest corner of the sub -basin. Sub - basin 4 encompasses Building 3 and will drain to the existing area inlet at the Southwest corner of the sub -basin. Sub -basin 5 encompasses Buildings 4 and 5 and the surrounding parking areas. Sub -basin t5 will discharge into the new area inlet and outfall storm drain discussed above. As stated previously, onsite detention is not required and the inlets and piping constructed in 1983 (Marriott project) will allow ' this project area to be collected into the existing drain system. Both the inlet capacities and the pipe network have been modeled and no adverse affects were indicated. Rim elevations will be adjusted to ' meet the design grading plan, and all of these changes are part of the models. ' The design process also includes a worst case scenario in which the the piping system becomes completely plugged and runoff is forced over existing structures, sidewalks and alike. Again no concern ' for flooding resulted from this unlikely event. In the original storm drainage report for this property, the coefficient of runoff used was 0.85, and the runoff coefficient for this P.U.D. site plan is 0.75. Therefore, the actual runoff from the site is less than what was used in the original design. ' The only offsite area that is included in the storm water runoff calculations is 0.15 acres along the northwesterly side of the Marriott Hotel. That area is an existing landscaped area that will have some ' new walks constructed in it. According to the drainage plan for the Marriott Hotel prepared by Simons, Li & Associates, Inc. and dated February 21, 1983, the drainage from the hotel roof is not discharging into this P.U.D. I 1 Arena Office Park P.U.D. Page 3 EROSION CONTROL 1 Since not all buildings will be constructed at the same time, only the groundcover for the building and parking area for a specific building will be disturbed at any given time. The construction sequence 1 enclosed is for Building No. 1. 1 Silt fence will be constructed along the northeast, southeast and southwest sides of the property at the time there is disturbance of the groundcover. Straw bale dikes will be placed around the area 1 inlets. Any areas that are disturbed but will not be hard -surfaced during construction for more than 6 to 8 weeks will be reseeded. 1 The storm water runoff calculations, detention pond calculations and erosion control calculations 1 are enclosed as a part of this report. The Marriott Drainage Report is also enclosed as an addendum to this report. 1 This report and the design of the drainage system for Arena Office Park P.U.D. are in 1 compliance with the current City of Fort Collins criteria. If you have any questions regarding this site or this report, please call. 1 Niki�16.Respectfully, � 1* 5028 Ck'• A COM Richard A. Rutherford, P.E. & L.S. # 5028 t0°rr►111n"1 1 President 1 enclosures 1 1 1 I� L 1 LI ' EROSION CONTROL COMPUTATION FOR ARENA OFFICE PARK P.U.D. I I 1 I I I F I STEWAU& SSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: Client: AIZ974,IS G17egs !Z& Sheet No. —of Project: '0 7 eC' I a Subject: I I I '' •� ,,�� /J CONSTRUCTION SEQUENCE PROJECT:. 044l � '-' STANDARD FORM C IQUENCE. FOR 19 ONLY COMPLETED BY: A3�,�, DATE: 51/O,`QS I�dicate by use of a bar line or symbols when erosion control measures will be installed. jor modifications to an approved schedule may require submitting a new schedule for approval by the City Engineer. ' YEAR I MONTH j M I P, I FA I S a _S o _l_�__U___�__;__i �ERLOT GRADING ! I I WIND EROSION CONTROL 'Soil Roughing _ I Perimeter Barrier --t -- i Additional Barriers 'Vegetative Methods ! Soil Sealant Other RINFALL EROSION CONTROL 'STRUCTURAL: Sediment Trap/Basin Inlet Filters — - — Straw Barriers Silt Fence Barriers Sand Bags Bare Soil Preparation 'Contour Furrows Terracing Asphalt/Concrete Paving — Other 'VEGETATIVE: Permanent Seed Planting Mulching/Sealant 'Temporary Seed Planting -Sod Installation Nettings/Mats/Blankets Other ------------------------------ SIJJCTURES: INSTALLED BY C�,C. MAINTAINED BY VEGETATION/MULCHING CONTRACTOR )JE SUBMITTED 7 — 9 15 APPROVED BY CITY OF FORT COLLINS ON ISF-C: 1989 J I'm r RAINFALL PERFORMANCE STANDARD EVALUATION' --------------------------------------------------------------------- PROJECT: A R E/V,4 OFF I C E PAPL/C. STANDARD FORM A COMPLETED ---------------------------------------------- BY: R. A .9, DATE:s-lzz lO � --�----J---•- -_----DATE_ - DEVELOPED ERODIBILITY Asb Lsb Ssb Lb Sb I PS SUBBASIN- (feet)- EA,T/4e ---ZONE---- MODERATE -(ac)-- 3.13,57-44 -(ft)_- (,ZO' --(%) - / % GLO., --(%)--I--(e)-- 7Z9 yo S i -ra 9 EFFECTIVENESS CALCULATIONS -------------------------------------------------------------------- PROJECT: Att.r.04 OFF/cE Pq&k P U. D, STANDARD FORM B COMPLETED BY: Q,q.t2. DATE: 5 as i I Erosion Control C-Factor P-Factor Method Value Value Comment I ------------ ------ Be. D 6 --------------------- 0,01 --------- -- / Ob '4Sp!{4t.'r� LONG. 0.01 / Z. O g A �. . $ A 2 s �e0v.vj STRAty /. 0, /,0 o O. 7 e .a �. SALEJ SILT FENCE /,00 4, bo /, ov O.SO MAJORI PS SUB AREA BASIN (%) 1BASINI (Ac) I CALCULATIONS 6.+7;r qq C—N71e .i iTi2a 77•/� 11T$ i Z-BSAC (0.01 x Z.09) t (/.00 k 0,74) Z• 8 S=0.27¢. w T e P = 0•,70 x 0, 80 � 0. 4-0 E Fr, _ �l— (0.Z7�xa40)1X /00 Ole.. 77. 9 % ----------------------------------------------------------------------� HDI/SF-B:1989 HYDROLOGY FOR ARENA OFFICE PARK P.U.D. I 1 STEWART&kSSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: Client: �ol� ��QS L Sheet No. ¢ of Project: Subject: %f/�/rj�Cf� W s STEWART&ASSOCIATES 103 S. 938 RF , FORT gOLLINS, CO 80521 Consulting Engineers and Surveyors By: Date: Client: Sheet No. S of Project: Subject: I ' - , 1 , Y ." i 1 , ' - - 171i. �r -f xa - 7 - 2jp� ' D �3 _ 7t--- . , I STEWART&OSSOCIATES 103 PH. 4S8. MELD1 RUAMX 4 8 2 93C8O2LLINS, CO 80521 Consulting Engineers and Surveyors By: Date: Client: 1r;-0-111111:5- Sheet No. wof — Project: Subject: 2"ef S.- 7i 7 .-45 !7�T'7'a Z T ;— -------- -- pi 7 I n I 1 1 11 1 1 1 1 1 1 i 1 1 1 1 1 STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: Client: o%�% !✓��%o-S' Z/Sheet No. % of Project: Subject: -1-7 a`'vc- _ r , !o J , 1�ivQ'� - Tv Gv/✓':.rJ?,✓�/J ,L�'r�i.✓.'.._ _G'P 2 76 s- _ y3 : T '2 STEWART&ASSOCIATES 103 PH. S. MEL933DRUM1, FORT COLLINS, CO 80521 482-FAX 482-9382 Consulting Engineers and Surveyors By: Date: Sheet No. Of Project: Subject: �! �e�e— if XT T ff art 2. 1w at 7 '31 7 a- �7— -7 J -7 It A 7-Si 2,Y /1 77 i 7-11 F; :1. lift iII is FFT t STEWART&JkSSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: Client: ZZE;�a "wJ5" 21al Sheet No. of Project: Subject: T- 7S1 k 7 7 Z 7-1 I 11 1 r fi t STEWART&kSSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: Client: 4��ay .11� Sheet No. Hof Project: � /��,` Subject:- Z�i'vi/?� C�2/G' --5- 0 IU DRAINAGE CRITERIA MANUAL RUNOFF 50 30 F- 20 z w U In w 10 z w a O 5 w ¢ 3 O U 2 w H k_= 1 ,r ,■■ ��■� j■■■■INNNINN Nil 11 2 .3 .5 ' 1 IS 2 3 5 10 20 VELOCITY IN FEET PER SECOND FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR :1 USE WITH THE RATIONAL FORMULA. *MOST FREQUENTLY OCCURRING "UNDEVELOPE D" LAND SURFACES IN THE DENVER REGION. REFERENCE: "Urban Hydrology For Small Watersheds" Technical Release No. 55, USDA, SCS Jan. 1975. 5 -1-84 URBAN DRAINAGE & FLOOD CONTROL DISTRICT I� No Text I J 1 1 ' HYDRAULIC DESIGN ELEMENTS FOR ' ARENA OFFICE PARK P.U.D. I I I.J I I I I L 11 STEWART&OSSOCIATES 103 482-9S. MEL33DRUM, FORT COLLINS482-9382 , CO 80521 PH. 1 FAX Consulting Engineers and Surveyors By: k4— Date: e4-7,5 Client: L�S • L7-6. Sheet No. of Project: Iz, t t (Z-Y-- Subject: L T -3 vjJ 0 10'% - Vi cz 7.41 A%Ny.. L IX ---- --- --- ZO T 4 y" STORM SEWER SYSTEM DESIGN USING UDSEWER MODEL Developed by Dr. James Guo, Civil Eng. Dept, U. of Colorado at Denver Metro Denver Cities/Counties & UDFCD Pool Fund Study USER:Stewart and Associates -Ft Collins Colorado .............................. ' ON DATA 08-04-1995 AT TIME 10:52:51 VERSION=01-30-1995 *** PROJECT TITLE :ARENA OFFICE PARK P.U.D. ** RETURN PERIOD OF FLOOD IS 100 YEARS C�Nnr;DNS *** SUMMARY OF HYDRAULICS AT MANHOLES ------------------------------------------------------------------------------ MANHOLE CNTRBTING RAINFALL RAINFALL DESIGN GROUND WATER COMMENTS ID NUMBER AREA * C DURATION INTENSITY PEAK FLOW ELEVATION ELEVATION ' ------------------------------------------------------------------------------- MINUTES INCH/HR CFS FEET FEET 1.00 0.00 0.00 0.00 9.07 6.01 6.01 OK ' 2.000.00 0.00 0.00 9.07 11.00 6.61 OK 3.00 0.00 0.00 0.00 6.16 14.09 6.95 OK 31.00C�'�' 0.00 0.00 0.00 3.80 11.50 7.05 OK 4.00 Cr'7- 0.00 0.00 0.00 2.39 15.00 7.16 OK K MEANS WATER ELEVATION IS LOWER THAN GROUND ELEVATION ** SUMMARY OF SEWER HYDRAULICS NOTE: THE GIVEN FLOW DEPTH -TO -SEWER SIZE RATIO= .9 ------------------------------------------------------------------------------- SEWER MAMHOLE NUMBER SEWER REQUIRED SUGGESTED EXISTING ID NUMBER UPSTREAM DNSTREAM SHAPE DIA(RISE) DIA(RISE) DIA(RISE) WIDTH ID NO. ID NO. (IN) (FT) (IN) (FT) (FT) -------------- --- ---(IN)-(FT) ----------------------------- 100.00 2.00 1.00 ROUND 19.69 21.00 24.00 0.00 200.00 3.00 2.00 ROUND 16.61 18.00 24.00 0.00 201.00 31.00 3.00 ROUND 8.63 18.00 18.00 0.00 300.00 4.00 3.00 ROUND 12.72 18.00 24.00 0.00 IMENSION UNITS FOR ROUND AND ARCH SEWER ARE IN INCHES IMENSION UNITS FOR BOX SEWER ARE IN FEET EQUIRED DIAMETER WAS DETERMINED BY SEWER HYDRAULIC CAPACITY. SUGGESTED DIAMETER WAS DETERMINED BY COMMERCIALLY AVAILABLE SIZE. 1OR A NEW SEWER, FLOW WAS ANALYZED BY THE SUGGESTED SEWER SIZE; OTHERWISE, XISITNG SIZE WAS USED L� 1 t•ve'a _1-, 91 - I liC-tuA<-- GAS ' CArr�mari5 ----------- SEWER DESIGN COMMENT ------------------------------------ FLOW NORMAL NORAML CRITIC CRITIC ------------ FULL FROUDE 'ID FLOW Q FULL Q DEPTH VLCITY DEPTH VLCITY VLCITY NO. ----------------------------------------------------------------------------- NUMBER CFS CFS FEET FPS FEET FPS FPS 9.1 15.4 1.10 5.11 1.08 5.23 2.89 0.95 V-OK '100.0 200.0 6.2 16.5 0.85 4.86 0.89 4.58 1.96 1.07 V-OK 201.0 3.8 27.1 0.38 10.80 0.76 4.2.1 2.15 3.67 V-OK 300.0 2.4 13.0 0.58 �ROUDE NUMBER=O INDICATES THAT A 3.16 PRESSURED 0.57 FLOW OCCURS 3.21 0.76 0.86 V-OK ---------------------------------------------------------------------- SEWER SLOPE INVERT ELEVATION BURIED DEPTH COMMENTS ID NUMBER UPSTREAM DNSTREAM UPSTREAM DNSTREAM $ (FT) (FT) (FT) (FT) ---------------------------------------------------------- 100.00 0.70 3.12 1.02 5.88 2.99 OK 200.00 0.80 4.47 3.11 7.62 5.89 OK 201.00 300.00 10.00 0.50 5.90 5.25 4.40 4.43 4.10 7.75 8.19 7.67 OK OK K MEANS BURIED DEPTH; -IS GREATER THAN REQUIRED SOIL COVER OF 1 FEET t** SUMMARY OF HYDRAULIC GRADIENT LINE ALONG SEWERS -------------------------------------------------- 'SEWER SEWER SURCHARGED CROWN ELEVATION ID NUMBER LENGTH LENGTH UPSTREAM DNSTREAM FEET FEET FEET FEET 100.00 300.00 200.00 170.00 201.00 15.00 300.00 165.00 RSS'ED=PRESSURED FLOW; ----------------------------- WATER ELEVATION FLOW UPSTREAM DNSTREAM CONDITION FEET FEET ------------------------ 300.00 5.12 3.02 6.61 6.01 PRSS'ED 170.00 6.47 5.11 6.95 6.61 PRSS'ED 11.50 7.40 5.90 7.05 6.95 JUMP 130.03 7.25 6.43 7.16 6.95 SUBCR JUMP=POSSIBLE HYDRAULIC JUMP; SUBCR=SUBCRITICAL FLOW ** SUMMARY OF ENERGY GRADIENT LINE ALONG SEWERS ----------------------------------------------- UPST MANHOLE SEWER JUNCTURE LOSSES DOWNST MANHOLE SEWER ID NO - --------------------------------------------------------------------------- MANHOLE ID NO. ENERGY ELEV FT FRCTION FT BEND K COEF BEND LOSS FT LATERAL K COEF LATERAL LOSS FT MANHOLE ID ENERGY FT 100.0 2.00 6.74 0.73 0.19 0.00 0.00 0.00 1.00 6.01 '200.0 3.00 7.00 0.19 1.32 0.08 0.00 0.00 2.00 6.74 201.0 31.00 7.12 0.02 1.32 0.09 0.00 0.00 3.00 7.00 300.0 4.00 7.17 0.11 0.00 0.00. 0.25 0.06 3.00 7.00 ' BEND LOSS =BEND K* FLOWING FULL VHEAD IN SEWER. LATERAL LOSS= OUTFLOW FULL VHEAD-JCT LOSS K*INFLOW FULL VHEAD FRICTION LOSS=O MEANS IT IS NEGLIGIBLE OR POSSIBLE ERROR DUE TO JUMP. ' FRICTION LOSS INCLUDES SEWER INVERT DROP AT MANHOLE NOTICE: VHEAD DENOTES THE VELOCITY HEAD OF FULL FLOW CONDITION. A MINIMUM JUCTION LOSS OF 0.05 FT WOULD BE INTRODUCED UNLESS LATERAL K=O. ' FRICTION LOSS WAS ESTIMATED BY BACKWATER CURVE COMPUTATIONS. L'L ----------------------------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING ' DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD IISER Stewart and Associates -Ft Collins Colorado ............................... ON DATE 08-04-1995 AT TIME 11:08:15cnDw'L_ ** PROJECT TITLE: AREA INLET C ATE, ' *** GRATE INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 4 ' INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: INLET GRATE WIDTH (ft)= 1.35 INLET GRATE LENGTH (ft)= 2.00 ' INLET GRATE TYPE =Type 16 Grate Inlet NUMBER OF GRATES 1.00 SUMP DEPTH ON GRATE (ft)= 0.00--6---- ' GRATE OPENING AREA RATIO (%) = 0.60 IS THE INLET GRATE NEXT TO A CURB ?-- NO Note: Sump is the additional depth to flow depth. ' STREET GEOMETRIES: STREET LONGITUDINAL SLOPE ($) = 1.00 STREET CROSS SLOPE M = 2.00 STREET MANNING N = 0.016 ' GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 ' STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 8.84 ' GUTTER FLOW DEPTH (ft) = 0.30 FLOW VELOCITY ON STREET (fps)= 2.63 FLOW CROSS SECTION AREA (sq ft)= 0.91 GRATE CLOGGING FACTOR (%)= 20.00 ' CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: ' FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 2.39 G� IDEAL GRATE INLET CAPACITY (cfs)= 3.33 BY FAA HEC-12 METHOD: FLOW INTERCEPTED (cfs)= 2.39-0-� ' CARRY-OVER FLOW (cfs)= 0.00 BY DENVER UDFCD METHOD: FLOW INTERCEPTED (cfs)= 2.39 CARRY-OVER FLOW (cfs)= 0.00 73 t----------------------------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING ' DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD 137SER Stewart -and -Associates -Ft -Collins -Colorado ........ ON DATE 08-04-1995 AT TIME 11:13:33 '*** PROJECT TITLE: AREA INLET �O�CPc-lEs ' *** GRATE INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 31 ' INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: INLET GRATE WIDTH (ft)= 1.35 INLET GRATE LENGTH (ft)= 2.00 ' INLET GRATE TYPE =Type 16 Grate Inlet NUMBER OF GRATES 1.00 SUMP DEPTH ON GRATE (ft)= 0.10 --b S GRATE OPENING AREA RATIO M = 0.60 ( e >rwLtC IS THE INLET GRATE NEXT TO A CURB ?-- NO Note: Sump is the additional depth to flow depth. ' STREET GEOMETRIES: ' STREET LONGITUDINAL SLOPE (%) = 1.00 STREET CROSS SLOPE (%) 2.00 STREET MANNING N = 0.016 GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 ' STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 10.94 ' GUTTER FLOW DEPTH (ft) = 0.34 FLOW VELOCITY ON STREET (fps)= 2.87 FLOW CROSS SECTION AREA (sq ft)= 1.32 GRATE CLOGGING FACTOR (%)= 20.00 CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: \ FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 3.80 ' IDEAL GRATE INLET CAPACITY (cfs)= 5.80 BY FAA HEC-12 METHOD: FLOW INTERCEPTED (cfs)= 3.80 AkLL INTEV_,CX�Trz� CARRY-OVER FLOW (cfs)= 0.00 BY DENVER UDFCD METHOD: FLOW INTERCEPTED (cfs)= 3.80 CARRY-OVER FLOW (cfs)= 0.00 t----------------------------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING ' DEVELOPED BY DR. JAMES GUO, CIVIL ENG,DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD `SER:Stewart and Associates -Ft Collins Colorado. ... .. ... .......... .. ON DATE 08-04-1995 AT TIME 11:09:38 ** PROJECT TITLE: AREA INLET %�CCUAL_ 1NV�r r� � ' *** GRATE INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 2 ' INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: ' INLET GRATE WIDTH (ft)= 1.35 INLET GRATE LENGTH (ft)= 2.00 ' INLET GRATE TYPE =Type 16 Grate Inlet NUMBER OF GRATES 1.00 SUMP DEPTH ON GRATE (ft)= 0.0 0 -a -----" ' GRATE OPENING AREA RATIO M = 0.60 IS THE INLET GRATE NEXT TO A CURB ?-- NO Note: Sump is the additional depth to flow depth. ' rt STREET GEOMETRIES: ' STREET LONGITUDINAL SLOPE ($) = 1.00 STREET CROSS SLOPE ($) 2.00 STREET MANNING N = 0.016 ' GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 ' STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 9.69 GUTTER FLOW DEPTH (ft) = FLOW VELOCITY ON STREET (fps)= 0.32 2.72 FLOW CROSS SECTION AREA (sq ft)= 1.06 GRATE CLOGGING FACTOR ($)= 20.00 ' CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: ' FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 2.88 ' IDEAL GRATE INLET CAPACITY (cfs)= 3.62 BY FAA HEC-12 METHOD: Au_ *4�FLOW INTERCEPTED (cfs)= 2.88a' ' CARRY-OVER FLOW (cfs)= 0.00 BY DENVER UDFCD METHOD: FLOW INTERCEPTED (cfs)= 2.88 ' CARRY-OVER FLOW (cfs)= 0.00 2S ,---------------------------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD 'SER:Stewart and Associates -Ft Collins Colorado .. .... .......... ... ...... ON DATE 08-04-1995 AT TIME 07:10:17 ** PROJECT TITLE: AREA INLET r.y r,;,.,.,f•. r,_, ' *** GRATE INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 4 ' INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: ' INLET GRATE WIDTH (ft)= 1.35 INLET GRATE LENGTH (ft)= 2.00 t INLET GRATE TYPE =Type 16 Grate Inlet NUMBER OF GRATES 1.00 ��• SUMP DEPTH ON GRATE (ft)= 1.00 �= ' GRATE OPENING AREA RATIO (%) = 0.60 IS THE INLET GRATE NEXT TO A CURB ?-- NO Note: Sump is the additional depth to flow depth. STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (%) = 1.00 ' STREET CROSS SLOPE M = 2.00 STREET MANNING N = 0.016 ' GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 ' STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 16.75 ' GUTTER FLOW DEPTH (ft) = FLOW VELOCITY ON STREET (fps)= 0.46 3.56 FLOW CROSS SECTION AREA (sq ft)= 2.93 ' GRATE CLOGGING FACTOR (o)= CURB OPENNING CLOGGING FACTOR(%)= 20.00 10.00 INLET INTERCEPTION CAPACITY: FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 10.50`- — -, ' IDEAL GRATE INLET CAPACITY (cfs)= 10.52 BY FAA HEC-12 METHOD: FLOW INTERCEPTED (cfs)= 8.42 ' CARRY-OVER FLOW (cfs)= 2.08 BY DENVER UDFCD METHOD: FLOW INTERCEPTED (cfs)= 8.42 CARRY-OVER FLOW (cfs)= 2.08 Z(o UDINLET: INLET HYDARULICS AND SIZING DEVELOPED.BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD tSER:Stewart and Associates -Ft Collins Colorado ................. ... .. ON DATE 08-04-1995 AT TIME 07:15:36 ** PROJECT TITLE: AREA INLET ' *** GRATE INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 31 INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: ' INLET GRATE WIDTH (ft)= 1.35 INLET GRATE LENGTH (ft)= 2.00 ' INLET GRATE TYPE =Type 16 Grate Inlet NUMBER OF GRATES 1.00 SUMP DEPTH ON GRATE (ft)= 1.75 GRATE OPENING AREA RATIO (%) = 0.60 ' IS THE INLET GRATE NEXT TO A CURB ?-- NO Note: Sump is the additional depth to flow depth. STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (%) = 1.00 ' STREET CROSS SLOPE (%) = 2.00 STREET MANNING N = 0.016 GUTTER DEPRESSION (inch)= 1.50 ' GUTTER WIDTH (ft) = 2.00 ' STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 18.25 GUTTER FLOW DEPTH (ft) = 0.49 ' FLOW VELOCITY ON STREET (fps)= 3.74 FLOW CROSS SECTION AREA (sq ft)= 3.46 GRATE CLOGGING FACTOR (%)= 20.00 ' CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 13.00�_� IDEAL GRATE INLET CAPACITY (cfs)= 13.04 BY FAA HEC-12 METHOD: FLOW INTERCEPTED (cfs)= 10.43 CARRY-OVER FLOW (cfs)= 2.57 ' BY DENVER UDFCD METHOD: FLOW INTERCEPTED (cfs)= 10.43 CARRY-OVER FLOW (cfs)= 2.57 2I t----------------------------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD ISER:Stewart and Associates -Ft Collins Colorado..... ..... ..... ON DATE 08-04-1995 AT TIME 07:17:21 �,i>.X _ 1��� �•nc n ** PROJECT TITLE: AREA INLET ' *** GRATE INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 2 ' INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: ' INLET GRATE WIDTH (ft)= 1.35 INLET GRATE LENGTH (ft)= 2.00 ' INLET GRATE TYPE =Type 16 Grate Inlet NUMBER OF GRATES 1.00 _ SUMP DEPTH ON GRATE (ft)= 1.50 ' GRATE OPENING AREA RATIO (%) = 0.60 IS THE INLET GRATE NEXT TO A CURB ?-- NO Note: Sump is the additional depth to flow depth. ' STREET GEOMETRIES: ' STREET LONGITUDINAL SLOPE (%) = 1.00 STREET CROSS SLOPE (%) 2.00 STREET MANNING N = 0.016 ' GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 ' STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 17.88 ' GUTTER FLOW DEPTH (ft) = 0.48 FLOW VELOCITY ON STREET (fps)= 3.69 FLOW CROSS SECTION AREA (sq ft)= 3.32 ' GRATE CLOGGING FACTOR (%)= 20.00 CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: FOR 1 GRATE INLETS: DESIGN DISCHARGE (cfs)= 12.20 w ' IDEAL GRATE INLET CAPACITY (cfs)= 12.26 BY FAA HEC-12 METHOD: FLOW INTERCEPTED (cfs)= 9.81 ' CARRY-OVER FLOW (cfs)= 2.39 BY DENVER UDFCD METHOD: FLOW INTERCEPTED (cfs)= 9.81 CARRY-OVER FLOW (cfs)= 2.39 2,27 STORM SEWER SYSTEM DESIGN USING UDSEWER MODEL Developed by Dr. James Guo, Civil Eng. Dept, U. of Colorado at Denver Metro Denver Cities/Counties & UDFCD Pool Fund Study USER:Stewart and Associates -Ft Collins Colorado .............................. ON DATA 08-04-1995 AT TIME 09:12:36 VERSION=01-30-1995 r N-PmwM SYs��1 *** PROJECT TITLE :ARENA OFFICE PARK C�VkCIrY r�/7��1N6`-°M ** RETURN PERIOD OF FLOOD IS 100 YEARS M FfCltLcoG��� �� ** SUMMARY OF HYDRAULICS AT MANHOLES ------------------------------------------------------------------------------- 'MANHOLE CNTRBTING RAINFALL RAINFALL DESIGN GROUND WATER COMMENTS ID NUMBER AREA * C DURATION INTENSITY PEAK FLOW ELEVATION ELEVATION MINUTES INCH/HR CFS FEET FEET ------------ r 1.00 OK I** 2.00 3.00 31.00 4.00 MEANS WATER --------------------------------------- -- ----- ------------------ A 0.00 0.00 0.00 24.70 6.01T 6.01 OK 0.00 0.00 0.00 24.70 11.00 10.44 OK 0.00 0.00 0.00 12.50 14.09 13.15 OK 0.00 0.00 0.00 2.00 11.50 13.41 NO 0.00 0.00 0.00 10.50 15.00 13.96 OK ELEVATION IS LOWER THAN GROUND ELEVATION SUMMARY OF SEWER HYDRAULICS ----- -NOTE_ THE GIVEN FLOW DEPTH -TO -SEWER SIZE RATIO= .9 ------------------------------------------------------------------ SEWER MAMHOLE NUMBER SEWER REQUIRED SUGGESTED EXISTING ID NUMBER UPSTREAM DNSTREAM SHAPE DIA(RISE) DIA(RISE) DIA(RISE) WIDTH ID NO. ID NO. (FT) (IN) (FT) (IN) (FT) (FT) ----------------------------- 100.00 2.00 -----------(IN) 1.00 ROUND ---------------------------------- 28.67 30.00 24.00 0.00 200.00 3.00 2.00 ROUND 21.66 24.00 24.00 0.00 ' 201.00 31.00 3.00 ROUND 6.78 18.00 18.00 0.00 300.00• 4.00 3.00 ROUND 22.16 24.00 24.00 0.00 �IMENSION UNITS FOR ROUND AND ARCH SEWER ARE IN INCHES IMENSION UNITS FOR BOX SEWER ARE IN FEET REQUIRED DIAMETER WAS DETERMINED BY SEWER HYDRAULIC CAPACITY. UGGESTED DIAMETER WAS DETERMINED BY COMMERCIALLY AVAILABLE SIZE. OR A NEW SEWER, FLOW WAS ANALYZED BY THE SUGGESTED SEWER SIZE; OTHERWISE, EXISITNG SIZE WAS USED 1 -Zc, ----------- SEWER DESIGN OMMENT ------------------------------------ FLOW NORMAL NORAML CRITIC CRITIC MAX • %'!''! -��,,� -------------------- FULL FROUDE ID FLOW Q FULL Q DEPTH VLCITY DEPTH VLCITY VLCITY NO. NUMBER CFS CFS FEET FPS FEET FPS FPS ------------------------------------------------------------------------------- 24.7 15.4 2.00 7.86 1.74 8.53 7.86 0.00 V-OK '100.0 200.0 12.5 16.5 1.30 5.77 1.27 5.96 3.98 0.95 V-OK 201.0 2.0 27.1 0.28 8.96 0.54 3.4.5 1.13 3.60 V-OK 10.5 13.0 1.36 4.62 1.16 5.56 3.34 0.74 V-OK '300.0 ROUDE NUMBER=O INDICATES THAT A PRESSURED FLOW OCCURS ---------------------------------------------------------------------- SEWER SLOPE INVERT ELEVATION BURIED DEPTH COMMENTS ID NUMBER UPSTREAM DNSTREAM UPSTREAM DNSTREAM (FT) (FT) (FT) (FT) -------------------------------------------------------------------- 100.00 0.70 3.12 1.02 5.88 2.99 OK 200.00 0.80 4.47 3.11 7.62 5.89 OK 10.00 5.90 4.40 4.10 8.19 OK l201.00 300.00 0.50 5.25 4.43 7.75 7.67 OK K MEANS BURIED DEPTH IS GREATER THAN REQUIRED SOIL COVER OF 1 FEET ** SUMMARY OF HYDRAULIC GRADIENT LINE ALONG SEWERS ------------------------------------------------------------------------------- SEWER SURCHARGED CROWN ELEVATION WATER ELEVATION FLOW 'SEWER ID NUMBER LENGTH LENGTH UPSTREAM DNSTREAM UPSTREAM DNSTREAM CONDITION FEET FEET FEET FEET FEET FEET r100.00 300.00 300.00 5.12 3.02 10.44 6.01 PRSS ED 200.00 170.00 170.00 6.47 5.11 13.15 10.44 PRSSIED 201.00 15.00 15.00 7.40 5.90 13.41 13.15 PRSSfED 300.00 165.00 165.00 7.25 6.43 13.96 13.15 PRSS'ED RSS'ED=PRESSURED FLOW; JUMP=POSSIBLE HYDRAULIC JUMP; SUBCR=SUBCRITICAL FLOW ** SUMMARY OF ENERGY GRADIENT LINE ALONG SEWERS ------------------------------------------------------------------------------- MANHOLE SEWER JUNCTURE LOSSES DOWNST MANHOLE 'UPST SEWER MANHOLE ENERGY FRCTION BEND BEND LATERAL LATERAL MANHOLE ENERGY ID NO ID NO. ELEV FT FT K COEF LOSS FT K COEF LOSS FT ID FT ------------------------------------------------------------------------------- '100.0 2.00 11.40 5.39 0.19 0.00 0.00 0.00 1.00 6.01 200.0 3.00 13.40 0.78 1.32 0.32 0.25 0.90 2.00 11.40 201.0 31.00 13.43 0.01 1.32 0.03 0.00 0.00 3.00 13.40 4.00 14.14 0.54 0.00 0.00 0.25 0.20 3.00 13.40 '300.0 BEND LOSS =BEND K* FLOWING FULL VHEAD IN SEWER. LATERAL LOSS= OUTFLOW FULL VHEAD-JCT LOSS K*INFLOW FULL VHEAD LOSS=O MEANS IT IS NEGLIGIBLE OR POSSIBLE ERROR DUE TO JUMP. 'FRICTION FRICTION LOSS INCLUDES SEWER INVERT DROP AT MANHOLE NOTICE: VHEAD DENOTES THE VELOCITY HEAD OF FULL FLOW CONDITION. MINIMUM JUCTION LOSS OF 0.05 FT WOULD BE INTRODUCED UNLESS LATERAL K=O. 'A FRICTION LOSS WAS ESTIMATED BY BACKWATER CURVE COMPUTATIONS. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 TYPICAL EMERGENCY SPILLWAY DESIGN Weir Equation Q = C L (H) ^ 2/3 Q (cfs), C (weir coefficient), L (crest length, feet), H (energy head, feet) See Table 704 in this Report for C factors 64 = Weir Len H feet 3.1 = Weir Coefficient C) Weir Shape Broadcrested Spillway Over Sidewalk Design Flow 20.04 (cfs) Depth of flow H ft Flow Over Weir Q cfs Velocity s 0.15 11.53 1.201 0.16 12.70 1.240 0.17 13.91 1.278 0.18 15.15 1.315 0.19 16.43 1.351 0.20 17.75 1.386 0.21 19.09 1.421 0.22 20.47 1.454 0.23 21.88 1 1.487 0.24 23.33 1 1.519 NOTE: the 20.04 cfs is the max. Q100 This is assumina a fully Dluaaed Dioina system M>�x. W 6iMWN.K 5I.I:V. Mkx. I I.'3 Cross Section of Emergency Spillway PM NL %lpW II U ca Q C cis U U cz N U (n CZ � N cz �L L C� cm w O U co •L }� � L H (z > o =3 C/)cr o w c %I.- r N •C O mQ. a O O ca �_ �_ C G U5 II 00 II N W CD r 7 7 32 ca CL C: CU 0 C) -+--j C.) cu U COa) 15 za 6 75 CD 0) C: ca F— c ca -� 0 tqmia! 0 C.) 0 CD ctl 2 cc "Op E oll CU >% 'R =3 cn 0 0- w co 0 a z C: C'j 0 0 C) CODC) 0 0 c C N V3 co CD (ma JCC to to U CV �� 0) co 0 T W (M . . F T (D 0 , co �:q: teL 0) fj cr) V LO td, c6 cd ci ci 6 ca C u.2 CO co CD Lo w CM z 7 CM ... . V ". : CD . CO � 0 CM N N, CD cm �cq N. b CT .... :a 0 00 . 0.000600 m0 0000,000000: 6 cd, 6 a) u) rn ci 0 CIJ V'.: 4)O 00 co U) C%l CO'c CM tn 00, CM V CO 0 CM Itt W CO, 7 7CO IN cm N cm N a 0 (D. 0 0.0 .! 0 0 mq q q p , 0 0 a 0 . 0 0 pi C.) E Ln r (0 r r, T CD; T oi r N cm cm cm C6 cm N (DO V.- N: CM N cq N EL 6 6 6 6, 0' oi: 0' Q* 0 0 O LL 33 REFERENCED REPORT FOR ARENA .OFFICE PARK P.U.D. s� 11 [l DRAINAGE PLAN FOR MARRIOTT AT FORT COLLINS 7 Prepared for Roush Mitchell Ventures, Inc. PO Box 1208 Fort Collins, Colorado 80522 CD4 � , g 3 2'L .By Simons, Li & Associates, Inc. 3555 Stanford Road PO Box 1816 Fort Collins, Colorado 80522 Project Number CO-RMV-03 Revised February 21, 1983 3� ' I. INTRODUCTION ' This report presents the pertinent data, methods, assumptions and calcu- lations used in analyzing and preparing the drainage plan for the Marriott at ' Fort Collins. The proposed location for the facility is on a 5.11-acre site which is a part of the Strachan Subdivision Third Filing in southeast Fort Collins. The ' preliminary drainage plan for this subdivision was previously prepared by James H. Stewart and Associates, Inc. This report provides detailed infor- mation for the Marriott site considering its interaction with other parts of the subdivision. 1 Zlo 2 ' II. SUMMARY OF DATA AND DESIGN CONSIDERATIONS Considerations used in the analysis and design of the Marriott site are in compliance with the City of Fort Collins Storm Drainage Design Criteria and results of the Foothills Basin Drainage Master Plan. The proposed developments for the site being considered in this report provide for the hotel building which will occupy approximately 70,000 square ' feet (about 1.6 acres), approximately 0.5 acres of landscaped area, and the remainder paved parking and walkway (about three acres). An additional 4.1 acres of future development outside the Marriott property but within the Strachan Subdivision Third Filing were considered in the analysis to insure ' compatibility between this drainage plan and the overall subdivision drainage plan. A summary of the design parameters used in the analysis follows: ' 1. Initial storm: 10-year storm, frequency factor - 1.0. 2. Major storm: 100-year storm, frequency factor - 1.25. ' 3. Minimum allowable storm drain pipe diameter: 1511. 4. Minimum flow velocity: 2 fps. 5. Rational method runoff coefficients: Paved areas, roofed areas - 0.95 ' Landscaped areas - 0.25 6. Percentage impervious area for Marriott property: 90 percent. ' 7. Manning's n: concrete pipe 0.013. 8. Zoning: Public Building Area. 9. Detention: ed Mitchell and Co. paid the Warren Lake Co. for detention rights in Warren Lake. 1 1 11 3 ' III. ANALYSIS AND DESIGN 'OF" DRAINAGE PLAN ' This section summarizes the results of the drainage analysis for the Marriott site and surrounding area and presents the principal features of the site drainage plan. The total area considered in this design was approxi- mately 9.2 acres, including the 5.11-acre Marriott property. Figure 1 shows the boundaries of the area considered. Subbasins are delineated on the figure ' and flow arrows are shown indicating the general direction of the overland flow within each basin. In addition to the principal 9.2-acre site affected ' by the Marriott construction, off -site drainage areas contributing to the overall drainage plan were considered. These areas include the Strachan ' Continental Subdivision and the Foothills Square development (drainage reports prepared by James H. Stewart and Associates, Inc. 7/3/81 and 8/22/77 respectively). ' The Marriott site is relatively flat and generally slopes to the southeast. Because of the high ground to the north of the hotel, provisions for drainage of the walkway in this area were necessary. The discharges at various points on the lot were based upon the Rational Method. Inlet capacities were checked using the Fort Collins Storm Drainage Criteria Nomographs and storm drain pipe capacities were computed based upon ' Manning's Equation. A summary of the storm drain design calculations is pre- sented in Table 1. Additional supporting calculations are summarized in ' Appendices A and B. Drainage improvements required for the site, in addition to existing facilities, are: 1. Six type 13 inlets ' 2. Three standard manholes 3. 294 linear feet (LF) 24" reinforced concrete pipe (RCP) ' 4. 730 LF 18" RCP 5. 68 LF 8" RCP ' 6. 18 LF 6" RCP ' 7. 160 LF 8" ductile iron pipe 1 -1Z5 M IYrrr•.r r..v. /r..•..W Imo..,. ../..M...1I 0 � ` /• r+. n.vr d..rv.. r.tir� � ,T/fiLY •Jpry,( � \ ..w r i// i N/ll./i .•�Mr/ri✓wnN ' C I Q LL . '+ h rrr • I Z ,q ..........r..,, I N Ad 14 / �-./ - �• __ 7 / irk l- �_ � Ir � �•i s�.,.lNw .VOTE /.: ���:' , � -- � �-- / /Hrf!!M•lrlM r/.y // � .rr • �� j ..�..�� Total area considered in site drainage analysis Sub —basin boundary Sub -basin number 2 Design Point © Roof drain N o.wre.,w, /� IM,Vw IM/w`aV w0 Figure 1. Overlot grading and drainage plan. 1 1 5 - E1 i • �Bl�llinll� nllllllllllnllnl . � �11W1n1�11nIWllllllllnnnl �IIIn111111111111111111nn111111I11 n8lnllllllllllllillllllln1111 II�I�nlWllnnllllllnl •I•�Illlnllllllllnllni ®81�En11®�Ii111ni1111111n11W1 11111111111111111 n 1111111111111 i 11 '�, �IW1�lWllllllllllnnnlllllllll : 111�11111:�1�n1111nIWn1111111 � �f�111n0111�Ini1n1111111n11111i1 �8HIM III�linlllinnllllllllnl ' �01�111�IIf�11 'Wnllnlnlllnllll . i�11MIII111111111111in11n111111111 �= ®01=�1111 all �Illllllinlllllllln! �1�1�111�I�IE11llnlllilillllilnnl �Onlli�iln1111111111111111n1111111 � ®11111nlnlllllllllllimilli 1I ®�I�IEI�IilElillnllllilllllllnn �01�1�1�1�1;;�I�Illlllllllllllnllll �0 1@ I�Illllllllninnlill w E:; 4G I 6 ' Storm drainage facilities which currently exist on the site include a 30" ' R.C.P. which originates in the Foothills Square parking lot just west of John F. Kennedy (JFK) Parkway. This line passes beneath JFK Parkway and joins a 36" R.C.P. at Design Point 3 (see Figure 1). The 30" R.C.P. has a slope of approximately 1.3 percent and a capacity of 47 cfs. In addition, flows from the Strachan Continental Subdivision enter the site through three 19"x30" ' concrete arch pipes which pass under East Horsetooth Road flowing into a 27" R.C.P. having a slope of approximately 2.5 percent and capacity of 49 cfs. This line flows into the box of a 5' wide curb inlet. The curb inlet is con- nected to the drop inlet at Design Point 3 by a 21" R.C.P. having a slope of ' approximately 2.6 percent and capacity of 26 cfs. A 36" R.C.P. having a slope of approximately 0.8 percent and capacity of 60 cfs runs from Design Point 3 through Design Point 8 and into a large curb inlet on the south side of the property. Flows from this inlet are delivered to Warren Lake through three 26 5/8" x 3 3/4" arch pipes. According to the design by Stewart and ' Associates, these arch pipes have a total capacity of 160 cfs, which corresponds to the estimated 10-year flow at this point (see "Foothills Basin ' Master Drainage Plan," Resource Consultants, Inc., 1981). Additional drainage facilities were designed for the Marriott site to ' provide adequate on -site drainage for the 10-year storm. These facilities are shown in Figure 1. In addition, all -on- and off -site flows affecting the site ' were analyzed to insure that the proposed site plan provided sufficient drainage. A summary of the calculations is presented in Appendix B. These calculations indicate that the capacity of the existing drains is not suf- ficient to carry the 10-year flows. The excess flow at Design Point 3 (approximately 90 cfs) will pass overland through the parking lots and into ' the large inlet on the southeast side, of the -property -as -indicated by the large flow arrows in Figure 1. Considering the indicated discharge, the,,flow ' depth will be sufficient to overtop the curb at.the north end of the entrance off E. Horsetooth Road. It should be noted that it was necessary to increase the roadway elevations indicated on the Horsetooth Associates, site plan approximately halfway between E. Horsetooth Road and the north end of the island to prevent flow from passing out onto E. Horsetooth Road,..._,.. For the 100-year storm, the discharge. at E. Horsetooth Road and Stanford Road was estimated to be 270 cfs (see Foothills Basin Drainage Master Plan, ' Resources Consultants, Inc., 1981). Since the capacity of the 36" R.C.P. be- f\ 4( ' tween Design Point #3 and the large inlet is only 60 cfs, the overland flow ' will be approximately 210 cfs. Considering the existing profile of the curbs along E. Horsetooth Road, the amount of ponding on the site will be minimal. Some flow will pass through the south entrance onto E. Horsetooth Road and ' into Warren Lake. The remainder will flow overlot to the inlet where the excess will flow over E. Horsetooth Road into Warren Lake. 1 I a IV. DEWATERING FOR HOTEL FOUNDATION ' Results of the soils testing on the site indicate that the groundwater table is sufficiently high to necessitate design of a drainage system beneath the hotel building. Because of the elevation of the existing storm sewer and ' the hotel basement and swimming pool, it will be necessary to collect the groundwater from beneath the building into a small sump near the south corner ' of the building. This water will then be pumped into the storm drainage system. Preliminary analysis indicates that the peak flow rates from this ' sump arrangement will not exceed approximately 0.25 cfs, which will have mini- mal impact on the remainder of the drainage plan. 1 1 1 1 1 U3 .1 1 ' APPENDICES A AND B SUPPORTING CALCULATIONS u 1 1 r-- t LH ' SIMONS LI a ASSOCIATES CLIENT .JOB NO. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORADO DETAIL CHECKED BY COMPUTED BY O rr ' 115 r� Cc i d l l�ti p4°la 5� Sq sr4iawae all `t��P bRaFAJ Z �pPIA �,O��V ` A°t° Daoa -iLC-7 "*(a h DaAt0 s IY.E♦. ¢ O �Z a1F � irri P N J � N O A U FI�I Ci vi U' P 7,`/S 6,9 E.FIsrINC� 36"2.C.P � Fi�v«T � l�to� ' 3 5=0.9% Qcao=Ca9cr's OJ ' •N � ST T �6 _ 4 II S Cx.ST,u6 Z71`?L?. 66 QCA 1�ih s. z�•t. Exlsnl% slCIA ',to - S e-f s/o o f zfor l . \ cj ro. l-k "V"� fo 0 to 0 Th vzv t 0� Q (ZO,4\) = d.Ot oi91(3.00-q) = 3• ��r ' Sef 1v\ lelr+ ®C (�JoF+�> = 3.85, .17 SIMONS. LI a ASSOCIATES. CLIENT JOB NO. PAGE A--2 ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORAOO DETAIL CHECKED BY . COM►UTED BY 1 SG N IQY y S-ewer l,v►eS -Lv\\/4aN i � ® (A)av1'r) = C7,00 I I- _ . �n�e.r� Qo r�i. N. �� CSu�}�)= 0.01+/•qS(Ui1Z-)= a.�Ci se+ T,\je_r-i p 74- Z = a.Go+ 196 Cor►Z) = S—o9 76509 1 -cV-+ 041crF.s ( 0,In ll,P-s eJ+ubllsAed 6� 1 4 . —. ►���F►ti,e. rki Aog va�uSt�J 1 Q =cQil A uJ� � Irc C = %rU coe = O.9J for pcl.JQ� ITTcx4tci a` C-O 4 1 ' SINONS LI A ASSOCIATES CLIENT JOB NO. PAGE V-7 ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORADO DETAIL CHECKED BY COMPUTED BY Frer ��77 r 5 , ova vw +y A rta ' - :'I', ,✓v��� e �I vv, e a T coo u..K J, c� c� u AL ' /O rF�2 S io,�Nt Ca��cs Ji=<r4nt �o7NT' A = I.07A ,s= a% rC o I 1 I I T 3. S Q7oo = (O.53��1,2�� C71 L� (( 09) _ S 7.g Q = . (o G Flow o,- I/ =o.-73 C 7 i�1 .1 F I 1 IrI L_ I I I J I I SIMON& LI A ASSOCIATES CLIENT JOB NO. PAG� �LZ ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORADO DETAIL CHECKED BY COMPUTED BY T. =- oo�- �RFA Tom = g < y (/ .��C� Qjac �orr'L f-LOL,J 4o Des�yn �ol nT tr r -J r 5��v41.� is V= Flow 11z A l ll I Il , -1 1 1 1 1 SIMONS. U A ASSOCIATES CLIENT JOB NO. PAGE 2f ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORADO DETAIL CHECKED BY COMPUTED BY DVA—�LFLOW _ S Z. — = cur 6 S-f2z=9aCA r' %o—cep 57�r-�. Will Auw FioIv U,,,1I '�r bT 0vertca a+ fit' nuVA�- -e.hA c) 4 �4AL s l a (.,\ souk e plim " �� e \ro^�T� POwI,1A V-0tj par/elk�" 10-t ov\. 7 c, 50v tQSfi S�d,Q d l�t,e roper+J ' SIMON& LI & ASSOCIATES CLIENT Joe NO. PAO@ ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORADO DETAIL mf CHECKED BY COMPUTED BY 1��:►4pj L = zsc'r = I,vq+�.i� = alai A S = a% moo= S' & l vkPu r -r-00 = 7, z �.. /G�... ado 5s� �i.o��s�`(a.a3) _ /�• 9 C, ,vo= �o,53�Cr.Zs-X'r.L1�21Zs) �S Q= i�.3crts >It� Js p� (jse 01„95 K,C.A a,.u,.,, Z - 3 D/ = o.7v A=o.so7d�= �.3,rttl V= Q/A Tdin1T to L1 h I -2 -3 390/ /�Z3 =J,aSA 15 ' (c -1, ( vVL In T, CIO 1 SIMONS LI A ASSOCIATES CLIENT JOB NO. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS COlORn00 DETAIL CHECKED BV COMPUTED BY 1 Dcs�4nr �o�tir� 1 4=1'10i A= d.rqAJ s= /°/n 1 r- 1 Qlcucis I.Q�; SkcaC�t Nr 1 vJ6 ul)Zfit. —v C = e,a,tc�as _ 6o0,y9 A, "3 0 (09 ' 1—. = 310 � A r = 0. 6,' A, s = /. 9 % 1 T,e 3 G ,. / k,L -L 3.7 M k� / TiQD �- I 1 I ' SIMONS. LI A ASSOCIATES ENGINEERING CONSULTANTS FORT COLLINS. COLORADO CLIENT JOB No. PAc�L7/� PROJECT DATE CHECKED DATE DETAIL CHECKED BY COMPUTED BY ' Poor--- bou---t^ 113 I-=Zz0 A=O'78A� s=l7a s•71Co.v�) /oT-4c. F Low Tow- QT = 7. 1 Q = 13•� �s 7iv�Z �s =0.82,E=1.Z?=➢�=o.�89d2=�s.�' TOTAL. row i-OA- - 0^)-SITE ljlAiNAC)E F-.)Z, 160—yr 5Ta fz w� nn r00 _ 5, -I- a, -t G.Co -t;Z 1 1 1 1 SIWONS LI A ASSOCIATES CLIENT .JOB NO. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS. COLORADO DETAIL CHECKED BY COMPUTED BY 0 vaZtaio k0.1 S-aaws,x313 ?Iv C-,d S Qoas =-qZ,3 ter; Dear =l7 r-ft /=oz F—+ l zi rl ct v I . . CuRd /1t3LL•( Fz3 rNILkS vQUA p.Ef F i g N �cl I A!r , z -T Nt FT QAVI=t 60j: y ST2Ar-A4rl J? DfVI510�% 17iArlNA L! 4POtZ7 S1 EWART S J151Gt SIMONS. LI A ASSOCIATES CLIENT JOB NO. PAGES ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS, COLORADO DETAIL CHECKED BY COMPUTED BY ll��•rsfi CrLS4 CvL, � � {I (rv� aCe �� G� I = �% �-_ a I c�•,r• �� a�- 5 "�'o r,� �i io �-'ort4(U_5 l�ti� � — l7r O is Q Cil) I c / 47 c('S Q V EILA N T) c I !� = Z ,2 3 Awe Quo=L�•Ss�C.�'o�(-q,2�(Z•Z.3) _ �-i CfiS oyZ Jvp-�AT) fz" TL N ro b E Si G N 1�- 0; nf-r 3 'f+n.�ou o � Sir � rcu;rS QI7 +Z(o 4-7q Z c�s Q„ r_n_uANp FLow +a —3 ' SINONS LI 6 ASSOCIATES ENGINEERING CONSUL CLIENT JOB NO. PAGE 3yL2 TAWS FORT COLLINS COLORAOO PROJECT DETAIL DATE CHECKED DATE CHECKED BY COMPUTED BY ' D\/VIlFLouj F{Zoo- T TNL hT �Gi 3 OJT 1 I�r— oTAL 0 F—tL-A0 FLC;%J B4U114 3 1 C4s Zz =9a CA ' CArvy Tow+ wll1 L,s* ` 0verop ►LVy- �v IT/�= iJ�O�eiQil��( •. 511AIE �JJ �J1 , f� ��rl S OJ+ O VA0 P— 't j+ Aayse w +� ?Ics a a OILL J 15�