The URL can be used to link to this page

Home My WebLink AboutNEW BELGIUM BREWERY, 2ND FILING - PDP / FDP - 1-95B - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTN WhltcLAve -- h S Sher ood St D 3 mc mS Mel run StPnD m S Ho es St S Mns n StCOLLE E ......... �.._:............�........__....._._. �(i A, "'-._..........._.....;�i.........---- ; _-------- t._...._....... . a ,r P SaC r a I \.i :x r c i4 i \\ � First St ' d _��' Second 0 St Th rd m St m r m co 00 n a n � ' m O D <3 m T p C. Martine St m 0 p r\ Altn Vest St LEMAY AVE, ....................... j................ ................................. ....................... O p �.... _ 3 0 u. o h � r. o' a a` a� H ff a VICINITY MAP NOT TO SCALE 1 1 1� 1 1 1 1 1 1 1 1 1 1 1 1 1 1 '1 OVERDETENTION CALCULATIONS (FAA METHOD) Project Name: NEW BELGIUM BREWERY Project No.: 9067.02 By: JCY Checked By: Date: 6/24/97 BASIN "A" - CHECK EXISTING DETENTION Basin Area = 1.18 ac Total Area = 1.18 ac Composite "C" Value = 0.98 Allowable release = 2 cfs Net Allowable Release = 2 cfS TIME (min) I (in/hr) DEVELOPED NET ALLOWABLE RELEASED DELTA DELTA VOLUME (cf) RELEASE (cfs) VOLUME (co VOLUME (cf) VOLUME (ac-ft) 5 8.9 3088 2 600 2488 0.057 t0 6.5 4510 2 1200 3310 0.076 15 5.3 5464 2 1800 3664 0.084 20 4.4 6147 2 2400 3747 0.086 25 3.9 6765 2 3000 3765 0.086 30 3.5 7285 2 3600 3685 0.085 35 3.2 7771 2 4200 3571 0.082 40 2.9 8049 2 4800 3249 0.075 45 2.7 8430 2 5400 3030 0.070 50 2.6 8846 2 6000 2846 0.065 55 2.4 8968 2 6600 2368 0.054 60 2.3 9367 2 7200 2167 0.050 65 2.2 9696 2 7800 1896 0.044 70 2.1 9957 2 8400 1557 0.036 75 2.0 10147 2 9000 1147 0.026 80 1.9 10269 2 9600 669 0.015 85 1.8 10616 2 10200 416 0.010 90 1.7 10616 2 10800 -184 -0.004 95 1.7 10876 2 11400 -524 -0.012 100 1.6 11101 2 12000 -899 -0.021 105 1.5 11147 2 12600 -1453 -0.033 110 1.5 11448 2 13200 -1752 -0.040 115 1.5 11570 2 13800 -2230 -0.051 120 1.4 11657 2 14400 -2743 0.063 Required Volume I. APPENDIX B HYDROLOGIC CALCULATIONS 1 1 1_1 1 1 JR Engineering, Ltd. (970) 491-9888 2620 East Prospect Road, Suite 190, Fort Collins, Colorado 80525 07/08/97 NEW BELGIAN BREWERY FIRST FILING EROSION CONTROL COST ESTIMATE JOB NO. 9067.02 COMPLETED BY: DWK ITEM DESCRIPTION UNITS I UNIT COST I QUANTITY TOTAL COST 1 I SILT FENCE LF 1 $3.00 1 285 1 $855.00 2 1 STRAW BALE BARRIER LF 1 $150.00 1 5 1 $750.00 PRELIMINARY COST $1,605.00 TOTAL COST WITH FACTOR OF 150% $2,407.50 CITY RF.CF.F.r)mr. r09T ITEM DESCRIPTION UNITS I UNIT COST IQUANTITY ITOTALCOST 1 I RESEED/MULCH ACRE $650.00 7.2 $4,660.50 PRELIMINARY COST FACTOR OF 150% ESCROW AMOUNT = $6,990.75 X:\906702\EROSCOST.WB2 PAGE 1 of 1 CONSTRUCTION SEQUENCE STANDARD FORM C PROJECT: NEW BELGIAN BREWERY FERMENTATION TANKS SEQUENCE FOR 1997 ONLY COMPLETED BY: DWK DATE: 06/22/97 Indicate by use of a bar line or symbols when erosion control measures will be installed. Major modifications to an approved schedule may require submitting a new schedule for approval by the City Engineer. 1997 MONTH JULY AUGUST SEPTEMBER I OCTOBER NOVEMBER DECEMBER Demolition Grading Wind Erosion Control: Soil Roughing Perimeter Barrier Additional Barriers Vegetative Methods Soil Sealant Other Rainfall 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 BUILDING CONSTRUCTIO STRUCTURES: INSTALLED BY: CONTRACTOR MAINTAINED BY: DEVELOPER VEGETATION/MULCHING CONTRACTOR: TO BE DETERMINED BY BID DATE SUBMITTED: 06/97 APPROVED BY CITY OF FORT COLLINS ON: JR Engineering, Ltd. 2620 E. Prospect Rd., Ste. 190, Fort Collins, Colorado 80525 EFFECTIVENESS CALCULATIONS (970)491-9888 PROJECT: NEW BELGIAN BREWERY FIRST FILING STANDARD FORM B COMPLETED BY: DWK DATE: 07/08/97 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 SILT FENCE 1.00 0.50 STRAW MULCH 0.06 1.00 ESTABLISHED GRASS 0.08 1.00 BUILDING/DRIVE 0.01 1.00 MAJOR PS EROSION CONTROL SUB AREA BASIN (0/0) DEVICES BASIN (Ac) CALCULATIONS AC SILT FENCE E 5.25 SILT FENCE 100% BUILDING/DRIVE 2.58 ROADS/WALKS 0.00 STRAW/MULCH 2.67 WEIGHTED C-FACTOR 0.04 WEIGHTED P-FACTOR 0.80 EFF 97.17 OVERALL EFFECTIVENESS = 97.45 > 78.8, O.K. XA906702\NBB EFF1.WB2 PAGE 2 OF 2 JR Engineering, Ltd. 2620 E. Prospect Rd., Ste. 190, Fort Collins, Colorado 80525 EFFECTIVENESS CALCULATICINR (970)491-9888 PROJECT: NEW BELGIAN BREWERY FIRST FILING STANDARD FORM B COMPLETED BY: DWK DATE: 07/08/97 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 SILT FENCE 1.00 0.50 STRAW MULCH 0.06 1.00 ESTABLISHED GRASS 0.08 1.00 BUILDING/DRIVE 0.01 1.00 MAJOR PS EROSION CONTROL SUB AREA BASIN (%) DEVICES BASIN (Ac) CALCULATIONS AC 78.8 SILT FENCE A 1.18 SILT FENCE 100% BUILDING/DRIVE 0.89 ROADS/WALKS 0.00 STRAW/MULCH 0.29 WEIGHTED C-FACTOR 0.02 WEIGHTED P-FACTOR 0.50 EFF 98.89 B 1.03 SILT FENCE 0.00 BUILDING/DRIVE 0.45 ROADSIWALKS 0.00 STRAW/MULCH 0.58 WEIGHTED C-FACTOR 0.04 WEIGHTED P-FACTOR 0.80 EFF 96.95 SILT FENCE C 0.44 SILT FENCE 100% BUILDING/DRIVE 0.00 ROADS/WALKS 0.44 STRAW/MULCH 0.00 WEIGHTED C-FACTOR 0.01 WEIGHTED P-FACTOR 0.80 EFF 99.20 STRAW BALE BARRIER D 0.51 SILT FENCE 0.00 BUILDING/DRIVE 0.18 ROADS/WALKS 0.00 STRAW/MULCH 0.33 WEIGHTED C-FACTOR 0.04 WEIGHTED P-FACTOR 0.80 EFF 96.61 XA906702\NBB EFFI.WB2 PAGE 1 OF 2 JR ENGINEERING, LTD. RAINFALL PERFORMANCE STANDARD EVALUATION STANDARD FORM A PROJECT: NEW BELGIAN BREWERY FIRST FILING COMPLETED BY: DWK DATE: 06/27/97 DEVELOPED ERODIBILITY Asb Lsb Ssb Lb Sb PS SUBBASIN ZONE (AC) (FT) (%) (FT) (%) (%) A 1.18 340 3.0 B 1.03 120 1.0 C 0.44 635 0.4 D 0.51 275 1.6 E 5.25 690 1.0 8.41 1 1 1 43.0 1 1.3 1 78.8 PS is taken from Table 8-a (Table 5.1, Erosion Control Reference Manual) by interpolation. Required PS = 78.8 1' 1 APPENDIX D ' EROSION CONTROL EFFECTIVENESS CALCULATIONS, ' SCHEDULE, AND COST ESTIMATE H 11 H 1 ' Project No.: Project Name: 9067.02 New Belgium Brewery First Filing Detention Pond Volume By: DWK Date: 6/30/97 Contour Surface Incremental Cumulative Elevation Area Volume Volume (ft.) (sq. ft.) (cu. ft.) (cu. ft.) 46.00 0 0 0 47.00 7663 3832.00 3832 48.00 16381 12022.00 15854.00 49.00 24611 20496.00 36350.00 ' Required Volume = Total Volume = ' Retention Pond Volume 1 0.71 ac-ft 0.71 ac-ft @ 4948.73 Contour Surface Incremental Cumulative Elevation Area Volume Volume (ft.) (sq. ft.) (cu. ft.) (cu. ft.) 51.00 0 0 0 52.00 1285 643 643 53.00 2790 1395.00 2038.00 54.00 9078 4434.00 6472.00 .Required Volume = ' Total Volume = 0.15 ac-ft 0.15 ac-ft @ 4954.00 OVERDETENTION CALCULATIONS (FAA METHOD) Project Name: NEW BELGIUM BREWERY Project No.: 9067.02 By: JCY Checked By: Date: 6/24/97 BASIN "E" DETENTION REQUIREMENTS Basin Area = 5.25 ac Total Area'= 5.25 ac Composite "C" Value = 0.74 Allowable release = 1.15 cfs Net Allowable Release = 1J5 CIS TIME (min) I (in/hr) DEVELOPED NET ALLOWABLE RELEASED DELTA DELTA VOLUME (cf) RELEASE (cfs) VOLUME (cf) VOLUME (cf) VOLUME (ac-ft) 5 8.9 10373 1.15 345 10028 0.230 10 6.5 15152 1.15 690 14462 0.332 15 5.3 18357 1.15 1035 17322 0.399 20 4.4 20653 1.15 1380 19273 0.442 25 3.9 22727 1.15 1725 21002 0.482 30 3.5 24476 1.15 2070 22406 0.514 35 3.2 26107 1.15 2415 23692 0.544 40 2.9 27040 1.15 2760 24280 0.557 45 2.7 28322 1.15 3105 25217 0.579 50 2.6 29720 1.15 3450 26270 0.603 55 2.4 30128 1.15 3795 26333 0.605 60 2.3 31469 1.15 4140 27329 0.627 65 2.2 32576 1.15 4485 28091 0.645 70 2.1 33450 1.15 4830 28620 0.657 75 2.0 34091 1.15 5175 28916 0.664 80 1.9 34499 1.15 5520 28979 0.665 85 1.8 35664 1.15 5865 29799 0.684 90 1.7 35664 1.15 6210 29454 0.676 95 1.7 36538 1.15 6555 29983 0.688 100 1.6 37296 1.15 6900 30396 0.698 105 1.5 37448 1.15 7245 30203 0.693 110 1.5 39462 1.15 7590 30872 0.709 115 1.5 38869 1.15 7935 30934 0.710 120 1.4 39161 1.15 8280 30881 0.709 Required Volume OVERDETENTION CALCULATIONS (FAA METHOD) Project Name: NEW BELGIUM BREWERY Project No.: 9067.02 By: JCY Checked By: Date: 6/24/97 BASIN "D" RETENTION REQUIREMENTS Basin Area = 0.51 ac Total Area = 0.51 ac Composite "C" Value = 0.63 Allowable release = 0.0 cfs Net Allowable Release = 9A TIME (min) I (in/hr) DEVELOPED NET ALLOWABLE RELEASED DELTA DELTA VOLUME (cf) RELEASE (cfs) VOLUME (cf) VOLUME (cf) VOLUME (ac-ft) 5 8.9 858 0 0 858 0.020 10 6.5 1253 0 0 1253 0.029 15 5.3 1518 0 0 1518 0.035 20 4.4 1708 0 0 1708 0.039 25 3.9 1880 0 0 1880 0.043 30 3.5 2024 0 0 2024 0.046 35 3.2 2159 0 0 2159 0.050 40 2.9 2236 0 0 2236 0.051 45 2.7 2342 0 0 2342 0.054 50 2.6 2458 0 0 2458 0.056 55 2.4 2492 0 0 2492 0.057 60 2.3 2603 0 0 2603 0.060 65 2.2 2694 0 0 2694 0.062 70 2.1 2766 0 0 2766 0.064 75 2.0 2819 0 0 2819 0.065 80 1.9 2853 0 0 2853 0.065 85 1.8 2950 0 0 2950 0.068 90 1.7 2950 0 0 2950 0.068 95 1.7 3022 0 0 3022 0.069 100 1.6 3084 0 0 3084 0.071 105 1.5 3097 0 0 3097 0.071 110 1.5 3181 0 0 3181 0.073 115 1.5 3215 0 0 3215 0.074 120 1.4 3239 0 0 3239 0.074 Required Volume = 2 X 0.07 = 0.14 ac-ft I. 1 APPENDIX C ' DETENTION/RETENTION POND CALCULATIONS 11 11 1 7 JR EnginesrbV 0 SUBDIVISION: New Belgium Brewery CALCULATED BY: PPK STORM DRAINAGE SYSTEM DESIGN DATA STORM 100 yr(developed) d= 1.25 DATE OWSN7 D.P. BASINS to ROUTING FLOWTIME tL td C INTENSIT AREA DIRECT RUNOF OTHER RUNOFF TOTAL RUNOFF STREET/CHANNEL PIPE STREET/CHNL IPIPE REMARKS LENGTH CHANNEL PIPE SLOPE ICAPACITY SLOPE SIZE CAPACIT DESIG VELOCIT DESIG VELOCITY LOC. (min) (fl) (min) (min) (min) (inmr) (ac) Ids) Ids) (cis) (%) ids) (%) (in) (cis) Ids) (ttls) (cis) (a/s) 1 2 3 4 4a 5 6 7 8 9 10 11 12 13 1 14 14e 15 16 17 18 19 20 21 22 23 A A 5.5 5.5 0.78 8.80 1.18 10.10 10.1 . B B 10.0 10.0 0.56 7.20 1.03 5.15 5.2 From Water, Waste 8 Land Report C C 5.0 5.0 0.95 9.00 0.44 3.96 4.0 From Water, Waste 8 Land Report D D 6.4 8.4 0.50 8.50 0.51 2.69 2.7 1.80 L 74.8 E E 10.9 10.9 0.59 6.98 5.25 27.19 27.2 1.80 L 74.8 Notes: 1. Column 4a identifies the type of diannel used to calculate the velocity for the travel time calculations 2. Column 14a identifies whether the street is a main arterial, collector, or local street for use in the street capacity calculations. Strom Drainage Design and TKhn" Creeds JR Engineering 0 SUBDIVISION: New Belgium Brewery CALCULATED BY: PPK TIME OF CONCENTRATION STORM 100 yr DATE 06/25/97 cf = 1.25 ti = 1 87(1.1 - C x QDD^0.5 S^(1/3) tc = ti + tL SUB -BASIN DATA INITIAL/OVERLAND TIME TRAVEL TIME FINAL tc REMARKS DESIG: AREA C LENGTH SLOPE ti LENGTH SLOPE VELOCITY tL (ac) (ft) N (min) (ft) N (ft/s) (min) (min) 1 2 3 4 5 6 7 7a 8 9 10 11 12 A 1.18 0.78 100 0.50 3.0 240 PA 0.70 1.59 2.5 5.5 B 1.03 0.56 10.0 C 0.44 0.95 5.0 D 0.51 0.50 25 2.00 3.6 250 PA 0.60 1.47 2.8 6.4 E 5.25 0.59 25 2.00 2.7 665 PA 0.50 1.34 8.3 10.9 Note: Column 7a codes the channel type for velocity calculations. Storm Drainage Design and Technical Criteria JR Engineering 0 SUBDIVISION New Belgium Brewery CALCULATED BY PPK STORM DRAINAGE SYSTEM DESIGN DATA STORM 10 yr(developed) d= 1.00 DATE 00,25197 D.P. BASINS toll ROUTING FLOW TIME tL tc' C INTENSIT AREA DIRECT RUNOF OTHER RUNOFF T TAIL RUNOFF TREET/ HANNEL PIPE STREET PIPE REMARKS LE NGT CHANNEL PIPE SLOPE CAPACITY SLOPE SIZE CAPACITY DESIG VELOCITY DESIG VELOCITY LOC. (min) (R) (min) (min) (min) (INhr) (go) (de) (do) (do) (%) (do) (%) (In) (ds) (de) (R/s) (ds) (fVe) 1 2 3 4 4a 5 6 7 6 9 10 11 12 13 14 14a 15 16 17 18 19 20 21 22 23 A A 10.1 10.1 0.78 2.51 1.18 2.3 2.3 B B C C D D T3 7.3 0.50 2.81 0.51 0.7 0.7 0.60 L 5.4 E E 12.1 12.1 0.59 2.31 6.25 7.2 7.2 1.00 L 6.9 Notes: 1. Column 4a identifies the type of channel used to calculate the velocity for the travel time calculations 2. Column 14a identifies whether the street is a main arterial, collector, or local street for use in the street capacity calculations. Storm Drainage Design and Technical Gnarl JR Engineering 0 SUBDIVISION: New Belgium Brewery CALCULATED BY: PPK TIME OF CONCENTRATION STORM 10 yr DATE 06/25/97 cf = 1.00 ti = 1.870.1 - C x Cf)D^0.5 S^(1/3) tc = ti + tL SUB -BASIN DATA INITIAUOVERLAND TIME TRAVEL TIME FINAL tc REMARKS DESIG: AREA C LENGTH SLOPE ti LENGTH SLOPE VELOCITY tL (ac) (ft) N (min) (ft) N (ft/s) (min) (min) 1 2 3 4 5 6 7 7a 8 9 10 11 12 A 1.18 0.78 100 0.50 7.6 240 PA 0.70 1.59 2.5 10.1 B 1.03 0.56 C 0.44 0.95 D 0.51 0.50 25 2.00 4.5 250 PA 0.60 1.47 2.8 7.3 E 5.25 0.59 25 2.00 3.8 665 PA 0.50 1.34 8.3 12.1 Note: Column 7a codes the channel type for velocity calculations. PA = Paved Area, PL = Pasture& Lawns, GW = Grassed Waterway, Storm Drainage Design and Technical Criteria JR Engineering Weighted Runoff Coefficients Project No: 9067.02 PPK New Belgium Brewery 06/25/97 This sheet calculates the composite "C" values for the Rational Method. Design Area Impervious "C" Pervious "C" ,tota (ac.) ,imp (ac.) Percent Imperv. Percent Pervious Comp. "C" A 0.95 0.25 1.18 0.89 75.4 24.6 0.78 B 0.95 0.25 1.03 0.45 43.7 56.3 0.56 C 0.95 0.25 0.44 0.44 100.0 0.0 0.95 D 0.95 0.25 0.51 0.18 35.3 64.7 0.50 E 0.95 0.25 5.25 2.58 49.1 50.9 0.59 SITE 8.41 4.54 54.0 46.0 0.63 EE Storm Drainage Design and Technical Criteria I. 1 APPENDIX A ' MAPS AND FIGURES 1 t 1 1 t H 1 F ' 6.2 Irrigation Ditches ' The Coy Ditch runs along the southerly portion of this site. The proposed improvements, with the the exception of storm sewer crossing for the outlet pipe from the proposed detention pond, do not impact said ditch. 6.3 Ditch Company Approval ' Ditch Company Approval is required for the pipe crossing previously discussed and a signature block has been added to the storm pipe profile sheet. 6.4 Maintenance Agreements ' The developer will be responsible for the maintenance of all temporary and permanent drainage structures. 7. REFERENCES 1 1. City of Fort Collins, "Storm Drainage Design Criteria and Construction Standards", ' (SDDCCS), dated May 1984, revised January 1997. ' 2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria Manual', Volumes 1 and 2, dated March, 1969, and Volume 3 dated September, 1992. ' 3. "Drainage and Erosion Control Report for New Belgium Brewery, Fort Collins, Colorado', Water, Waste & Land, Inc., March 30, 1995 (WW&L Report) 4. "Final Drainage, Erosion and Storm Water Quality Study East Vine Streets Facility tP.U.D., Phase One Final, City of Fort Collins", RBD. Inc. Engineering Consultants, Updated June 28, 1993. 1 8 ' placed as shown on the utility plan prior to earthwork operations. (See Appendix for erosion control plan and details.) The measures are designed to limit the overall sediment yield increase due to construction as required by the City of Fort Collins. A construction schedule is contained in the Appendix which shows the proposed construction starting in August 1997. ' 5.1 Dust Abatement During the performance of the work required by these specifications or any operations appurtenant thereto, whether on right-of-way provided by the City or elsewhere, the ' Contractor shall furnish all labor, equipment, materials, and means required. The Contractor shall carry out proper efficient measures wherever and as necessary to reduce dust nuisance, and to prevent dust nuisance, and to prevent dust which has originated from his operations ' from damaging crops, orchards, cultivated fields, and dwellings, or causing a nuisance to persons. The Contractor shall be liable for any damage resulting from dust originating from ' his operations under these specifications. ' 5.2 Maintenance All temporary and permanent erosion and sediment control practices must be maintained and ' repaired as needed to assure continued performance of their intended function. Maintenance is the responsibility of the Owner. ' 5.3 Permanent Stabilization For disturbed areas and soil stockpiles shall be seeded and mulched within 30 days of ' disturbance. Vegetation shall not be considered established until a ground cover is achieved which is demonstrated to be mature enough to control soil erosion to the satisfaction of the ' City Inspector and to survive severe weather conditions. 6. MISCELLANEOUS ' 6.1 Variances There are no variances requested with the development of the New Belgium Brewery First Filing. 1 7 3.7 Allowable Street Flow Capacities ' The New Belgium Brewery First Filing does not impact any street flows on the adjacent streets. Therefore, detailed calculations are not required or provided in this report. ' 3.8 Curb Inlet Design There are no curb inlets required or proposed with the development of the New Belgium ' Brewery First Filing. ' 3.9 Storm Sewer Design There is one storm sewer proposed with the development of this site consisting of the outfall ' pipe from the proposed detention pond in the southeast corner of the site. This pipe will be a 12" RCP as preliminarily approved by City Storm Drainage. (See Appendix for Calculations.) 4. DETENTION/RETENTION There are two facilities proposed with the New Belgium Brewery First Filing, a detention pond and a retention pond. The detention pond (pond E) will be located in the southeast portion of the site. This pond will outfall through a proposed 12" RCP into the existing underground storm sewer pipe in First Street. The retention pond (pond D) proposed for the westerly portion of the site has a total contributing area of 0.51 acres (Subbasin D). In the design for the original brewery, this area drained around the north side of the building to Pond A. However, due to the location of the ' proposed expansion, the grades do not allow adequate fall for this area to continue to outfall around the north side of the building. In order to minimize the size of this pond, all of the off - site runoff from Linden Street north of the proposed entrance in the northwest corner of the site are being diverted onto the site at that point and are routed to the proposed detention pond ' (pond E) in the southeast corner of the site. 5. EROSION CONTROL ' Erosion and sedimentation will be controlled on -site by the use of silt fence which will be installed prior to commencing any earthwork operations. Straw bale barriers will also be 1 6 ' adjustment factor, C is the runoff coefficient, and I is the rainfall intensity in inches per hour. The frequency adjustment factor, Cf, is 1.0 for the initial 10-year storm and 1.25 for the major ' 100-year storm. ' The appropriate rainfall intensity information was developed based on rainfall intensity duration curves in the SDDCCS Manual. ' In order to utilize the rainfall intensity curves, the time of concentration is required. The ' following equation was used to determine the time of concentration: ' t'=t;+t, (2) where tc is the time of concentration in minutes; t is the initial or overland flow time in ' minutes, and t, is the travel time in the ditch, channel, or gutter in minutes. The initial or overland flow time is calculated with the SDDCCS Manual equation: t; = [1.87(1.1 - CCf)LosJ/(S)oaa (3) ' where L is the length of overland flow in feet (limited to a maximum of 500 feet), S is the ' average slope of the basin in percent, and C and Cf are as defined previously. All hydrologic calculations associated with the sub -basins shown on Figure 3.1 are attached ' in the Appendix of this report. Table 3.1 provides a summary of the design flows for all Subbasins and Design Points (DP's) associated with this site. * All information for these basins taken from W W&L Report. G7 LJ I. 1 3.5 Proposed Drainage Plan ' A qualitative summarization of the drainage patterns within each subbasin and at each design point is provided in the following discussion paragraphs. ' Runoff from Subbasin A is conveyed to the existing detention area proposed and constructed as part of the original New Belgium Brewery. (Pond A in the WW&L Report.) The overall size of this pond has been reduced as a result of the proposed expansion. The outlet for this pond is into the existing underground storm sewer system that was designed and constructed as part of the original brewery and is ' adequate to accommodate the revised runoff. Subbasin B runoff is conveyed to the existing detention area proposed and constructed ' as part of the original New Belgium Brewery. (Pond B in the WW&L Report.) This basin and pond are not being modified with this expansion and no analysis has been completed for this basin. ' Runoff from Subbasin C is conveyed to the existing inlet on Buckingham Street that ' was proposed and constructed as part of the original New Belgium Brewery. This basin is not being modified with this expansion and no analysis has been completed for this basin. ' Runoff from Subbasin D is conveyed to a proposed retention pond (Pond D) located in the westerly portion of the site adjacent to Linden Street. Runoff from Subbasin E is conveyed to a proposed detention pond (Pond E) in the southeast corner of this site. The outlet for this pond will be through a proposed pipe ' into the existing underground storm sewer in First Street. ' 3.6 Hydrologic Analysis of the Proposed Drainage Conditions The Rational Method was used to determine both 10-year and 100-year peak runoff values for each Subbasin. Runoff coefficients were assigned utilizing Table 3-2 of the SDDCCS ' Manual. ' As stated above, the Rational Method was used for all hydrologic analyses for the project site. The Rational Method utilizes the SDDCCS equation: ' Q = CrCIA (1) ' where Q is the flow in cfs, A is the total area of the basin in acres, Cr is the storm frequency 1 4 1 3. DEVELOPED FLOWS ' 3.1 Method The Rational Method was used to determine both the 10-year and 100-year flows for the sub - basins indicated in this drainage report. A detailed description of the hydrologic analysis is provided in Section 3.6 of this report. ' Detention is required for this site and was provided in two detention ponds (Ponds A and B) ' for the original New Belgium Brewery. In order to accommodate the increased flows resulting .. from the proposed expansion of the brewery, additional storage will be provided in the form ' of a small retention area (Pond D) in the westerly part of the site and a new detention pond (Pond E) in the southeast portion of the site. ' The release rates for this site were calculated in the aforementioned WW&L Report and those values have been utilized for this study. Therefore, the hydrologic analysis was conducted for ' developed flows only. The resulting 10-year and 100-year runoff values were used to compute discharges at specific design points. ' 3.2 Offsite Flows ' Offsite flows enter this site from the north and west. These areas are identified on the attached "Final Drainage and Erosion Control Plan" and calculations are included in the Appendix,of this report. 1 3.3 Onsite Flows ' Flows within this site will take the form of overlot and street flow. All proposed grading has been designed to carry flows away from structures to the existing and proposed ' detention/retention areas. ' 3.4 General Flow Routing The site runoff will, in general, be routed to the southeast comer of the site to conform to the ' existing flow patterns. The final drainage pattern for this area has been developed to minimize the amount of reconstruction on site and to utilitze existing drainage patterns and facilities where possible. This will also enable the flows released from this site to be limited to historic ' rates. 1 3 1 reports for specific sites in this area and discussions with City Stormwater Staff. ' Information for this report was also gathered from the following studies: 1. "Drainage and Erosion Control Report for New Belgium Brewery, Fort Collins, Colorado', Water, Waste & Land, Inc., March 30, 1995 (WW&L Report) ' 2. "Final Drainage, Erosion and Storm Water Quality Study East Vine Streets Facility ' P.U.D., Phase One Final, City of Fort Collins", RBD. Inc. Engineering Consultants, Updated June 28, 1993. ' The overall drainage plan for the New Belgium Brewery First Filing has been prepared to be consistent with the above reports and the results of discussion with City Staff. 2. EXISTING DRAINAGE 1 Currently, offsite flows enter this site from a small area to the north via overland flow and from the west from Linden Street through an existing sidewalk chase/concrete pan that was designed and constructed as part of the original New Belgium Brewery. The flows leave the ' site through a detention pond (Pond A) that outlets into an existing underground storm sewer system that was designed and constructed as part of the original New Belgium Brewery. Said ' existing storm sewer system outlets into a swale along the west side of First Street and is conveyed to the Cache La Poudre River. ' In addition, the City of Fort Collins has constructed an area inlet near the outlet of the aforementioned underground storm sewer system that was connected to an existing ' underground storm sewer pipe in First Street. (Phis pipe also outlets into the Cache La Poudre River.) The intent of said area inlet was to collect the minor flows in this area to mitigate the ' standing water in the outfall swale during low flow (minor rainfall events and on -site irrigation) with the flows from the major storm still being conveyed to the Cache La Poudre ' River via the outfall swale. 2 1. INTRODUCTION ' 1.1 Project Location The New Belgium Brewery First Filing is the proposed expansion of the existing New Belgium Brewery. This project is located in Section 12, Township 7 North, Range 69 Hills West of the Sixth Principal Meridian, in the City of Fort Collins, Colorado. (See FIGURE 1 - ' VICINITY MAP.) More specifically, this site is bounded on the south by Buckingham Street, on the west Linden Street, on the north by the City of Fort Collins' Streets Facility, and on the ' east by un-platted. property. The site contains approximately 7.17 acres. 1.2 Site Characteristics ' The topography of this site is broken into two distinct areas, the existing brewery and the area of the proposed expansion. The existing brewery consists of a building, drive and parking ' area, landscaped area, and a sparse grassy area at the rear of the building. The area of the proposed expansion consists of average covered pasture land. This site slopes to the southeast ' at approximately one percent (1%). ' 1.3 Purpose and Scope of Report This report defines the proposed final drainage and erosion control plan for the New Belgium Brewery First Filing, including consideration of all on -site and tributary off -site runoff. 1.4 Design Criteria ' This report was prepared to meet or exceed the submittal requirements established in the City of Fort Collins' "Storm Drainage Design Criteria and Construction Standards" (SDDCCS), dated May 1984 and Revised January 1997. Runoff computations were prepared for the 10- year minor and 100-year major storm frequency utilizing the rational method. ' Where applicable, the criteria established in the "Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver Regional Council of Governments, has been ' utilized. ' 1.5 Master Drainage Basin & Other Drainage Reports This site is included in the Cache La Poudre River Master Drainage Basin. It is our ' understanding that a master plan and report does not exist for this basin. Therefore, drainage outfall points and release rates have been determined through review of previous drainage ' 1 1 ' L ' APPENDIX A MAPS AND FIGURES.......................................................10 APPENDIX B ' HYDROLOGIC CALCULATIONS 11 ...................................... ' APPENDIX C ' DETENTION/RETENTION POND CALCULATIONS ...................... 12 APPENDIX D EROSION CONTROL EFFECTIVENESS CALCULATIONS, SCHEDULE, AND COST ESTIMATE ................... 13 ' APPENDIX B ' HYDROLOGIC CALCULATIONS ...................................... 14 1 1 ' ii I. k ' TABLE OF CONTENTS PAGE CERTIFICATIONS............................................................ i TABLE OF CONTENTS....................................................... ii ' 1. INTRODUCTION.......................................................I 1.1 Project Location...................................................1 ' 1.2 Site Characteristics................................................. 1 1.3 Purpose and Scope of Report .........................................1 1.4 Design Criteria .................................................... 1 ' 1.5 Master Drainage Basin & Other Drainage Reports ........................ 2 2. EXISTING DRAINAGE..................................................2 ' 3. DEVELOPED FLOWS ................................................... 3 3.1 Method...........................................................3 ' 3.2 Offsite Flows......................................................3 3.3 Onsite Flows.....................................................3 ' 3.4 General Flow Routing .............................................. 3 3.5 Proposed Drainage Plan .............................................4 3.6 Hydrologic Analysis of the Proposed Drainage Conditions ................. 4 3.7 Allowable Street Flow Capacities ..................................... 6 3.8 Curb Inlet Design ............................. ..... . .. 6 3.9 Storm Sewer Design...............................................6 4. DETENTION/RETENTION............................................... 7 5. EROSION CONTROL ................................................... 7 6. MISCELLANEOUS.....................................................7 6.1 Variances........................................................7 6.2 Irrigation Ditches .................................................. 8 ' 6.3 Ditch Company Approval ................................... 8 6.4 Maintenance Agreements . ......... 8 ' 7. REFERENCES.........................................................8 1 July 8, 1997 Mr. Basil Hamdan City of Fort Collins Stormwater Utility 135 Mathews Fort Collins, CO 80521 RE: Final Drainage and Erosion Control Study for New Belguim Brewery First Filing. Basil; We are pleased to submit to you for your review and approval, this Final Drainage and Erosion Control Study for New Belguim Brewery First Filing. All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. We appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sincerely, JR Engineering, Ltd. Prepared by: David Klockeman, P.E. Project Manager Reviewed by; Patricia Kroetch, P.E. Project Manager 1 1 1 1 1 1 1 1 1 �1 1 1 1 n FINAL DRAINAGE AND EROSION CONTROL REPORT NEW BELGIUM BREWERY FIRST FILING (POUDRE RIVER DRAINAGE BASIN) Prepared for: NEW BELGIUM BREWING COMPANY 500 LINDEN FORT COLLINS, COLORADO 80524 Prepared by: JR Engineering, Ltd. 2620 East Prospect Road, Suite 190 Fort Collins, Colorado 80525 (970)491-9888 July 8, 1997 Job Number 9067.02