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HomeMy WebLinkAboutSEVEN GENERATIONS (FORMERLY EASTBROOK) OFFICE PARK - PDP - 4-06 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTNo Text R-M-P Medum Density Planned Residential District — designation for medium density areas planned as a unit (PUD) to provide a variation in use and building placements with a minimum lot area of 6,000 square feet R-L-M Low Density Multiple Family District— areas containing low density multiple family units or any other use in the R-L District with a minimum lot area of 6.000 square feet for one -family or two-family dwellings and 9,000 square feet for muttiple-famity dwellings. M-L Low Density Mobile Home District — designation for areas for mobile home parks containing independent mobile homes not exceeding 6 units per acre. M-M Medium Density Mobile Home District — designation for areas of mobile home parks containing independent mobile homes not exceeding 12 units per acre. B-G General Business District — district designation for downtown business areas, including a variety of permitted uses, with minimum tot areas equal to 112 of the total floor area of the building. B-P Planned Business District — designates areas planned as unit developments to provide business services while protecting the surrounding residential areas with minumum lot areas the same as R-M. H-B Highway Business District — designates an area of automobile -orientated busi- nesses with a minimum lot area equal to 1/2 of the total floor area of the building. B-L Limited Business District — designates areas for neighborhood convenience centers, including a variety of community uses with minimum lot areas equal to two times the total floor area of the building. C Commercial District —designates areas of commercial, service and storage areas. I-L Limited Industrial District —designates areas of light industrial uses with a minimum area of lot equal to two times the total floor area of the building not to be less than 20,000 square feet I-P Industrial Park District —designates light industrial park areas containing controlled industrial uses with minimum lot areas equal to two times the total floor area of the building not to be less than 20,000 square feet I-G General Industrial District —designates areas of major industrial development. T Transition District — designates areas which are in a transitional stage with regard to ultimate development - For current and more explicit definitions of land uses and zoning ciassifications, refer to the Code of the City of Fort Collins, Chapters 99 and 118. Table 3-3 RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS Chwacterof Swtaee Runoff Coefrk*w t Streets. Parking Lots, Drives: Asphalt.......... .................................... .......... ........ _..... ...................... 0.95 Concrete.................. ..................... ................................. _................. 0.95 Gravel......................................... _...................................................... 0.50 Roofs ...... Lawns, Sandy Soil: Flat <2% ............... __......... Average 2 to 7% ................ Steep >70/e ......................... Lawns, Heavy Soil: Flat <20/6 ................................... Average 2 to 7'/e ........................ Steep >7%................................ ... ..................... 0.95 ....................... _.................. 0.10 ......... _.... _... _..................... 0.15 ........................................... 020 ...................... 0.20 ...................... 0.25 ...................... 0.35 MAY 1984 34 DESIGN CRriERtA APPENDIX G FIGURES AND TABLES G 35 46 3250.0 28.9 80.0 .0150 .016 .250 .100 .300 .51 .50 .00180 1 36 45 2390.0 21.5 90.0 .0300 .016 .250 .100 .300 .51 .50 .00180 1 ' 37 50 70500.0 255.7 74.0 .0300 .016 .250 .100 .300 .51 .50 .00180 1 38 51 5200.0 41.7 40.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 39 53 2200.0 32.6 10.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 40 55 13400.0 218.6 45.0 .0070 .016 .250 .100 .300 .51 .50 .00180 1 112 172 4300.0 41.5 50.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 43 172 585.0 24.2 7.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 44 58 5000.0 42.3 40.0 .0050 .016 .250 .100 .300 .51 .50 .00180 1 144 159 1400.0 18.7 30.0 .0190 .016 .250 .100 .300 .51 .50 .00180 1 45 62 11000.0 117.6 60.0 .0080 .016 .250 .100 .300 .51 .50 .00180 1 46 60 3900.0 26.6 40.0 .0070 .016 .250 .100 .300 .51 .50 .00180 1 47 63 7200.0 88.0 40.0 .0080 .016 .250 .100 .300 .51 .50 .00180 1 ' 43 65 7200.0 96.5 40.0 .0060 .016 .250 .100 .300 .51 .50 .00180 1 49 67 5000.0 42.4 40 0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 .__-.-X 50 57 2400.0 19.5�. .0220 .016 .250 .100 .300 .51 .50 .00180 1 150 157 2700.0 20.4 65.0 .0080 .016 .250 .100 .300 .51 .50 .00180 1 51 70 7400.0 68.0 40.0 .0070 .016 .250 .100 .300 .51 .50 .00180 1 52 79 2200.0 14.7 - 70.0 .0050 .016 .250 .100 .300 .51 .50 .00180 1 53 75 2200.0 14.7 70.0 .0050 .016 .250 .100 .300 .51 .50 .00180 1 54 81 5500.0 50.9 60.0 .0030 .016 .250 .100 .300 .51 .50 .00130 1 55 208 6000.0 55.2 40.0 .0060 .016 .250 .100 .300 .51 .50 .00180 1 56 209 3500.0 31.7 40.0 .0030 .016 .250 .100 .300 .51 .50 .00180 1 57 85 13000.0 208.1 40.0 .0200 .016 .250 .100 .300 .51 .50 .00180 1 58 288 6000.0 41.3 50.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 581 184 3400.0 22.2 90.0 .0080 .016 .250 .100 .300 .51 .50 .00180 1 582 212 5000.0 34.2 85.0 .0200 .016 .250 .100 .300 .51 .50 .00180 1 59 211 1500.0 20.7 40.0 .0060 .016 .250 .100 .300 .51 .50 .00180 1 60 78 1500.0 24.6 47.0 .0050 .016 .250 .100 .300 .51 .50 .00180 1 ' 61 210 1050.0 12.2 _ 64.0 .0090 .016 .250 .100 .300 .51 .50 .00180 1 62 77 1800.0 3.3 99.0 .0070 .016 .250 .100 .300 .51 .50 .00180 1 621 306 865.0 5.9 66.0 .0090 .016 .250 .100 .300 .51 .50 .00180 1 622 303 1400.0 10.5 13.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 623 313 2200.0 3.4 33.0 .0100 .016 .250 - .100 .300 .51 .50 .00180 1 624 213 6200.0 70.7 43.0 .0130 .016 .250 .100 .300 .51 .50 .00180 1 . ' 63 193 9964.0 91.5 40.0 .0050 .016 .250 .100 .300 .51 .50 .00180 1 64 361 7200.0 66.0 40.0 .0130 .016 .250 .100 .300 .51 .50 .00180 1 650 88 2100.0 19.6 40.0 .0100 .016 .250 .100 .300 .51 .50 .00180 1 651 251 700.0 6.6 9.0 .0230 .016 .250 .100 .300 .51 .50 .00160 1 65 88 1200.0 5.7 10.0 .0300 .016 .250 .100 .300 .51 .50 .00180 1 ' 66 94 4700.0 27.3 20.0 .0200 .016 .250 .100 .300 .51 .50 .00180 1 67 86 10000.0 95.4 55.0 .0200 .016 .250 .100 .300 .51 .50 .00180 1 68 94 1900.0 17.9 55.0 .0150 .016 .250 .100 .300 .51 .50 .00180 1 681 288 850.0 7.5 55.0 .0150 .016 .250 .100 .300 .51 .50 .00180 1 69 95 7100.0 65.2 55.0 .0190 .016 .250 .100 .300 .51 .50 .00180 1 TOTAL NUMBER OF SUBCATCHMENTS, 79 ' TOTAL TRIBUTARY AREA (ACRES), 3195.20 FOOTHILLS BASIN - FULLY DEVELOPED CONDITION WITH REVISED RAINFALL 100-YEAR EVENT CITY MODIFIED ACE 99 PONDS 57 6 157 RATING CURVES FOR HOMESTATE SUBMITTAL 11-2000 FILENAME FOOT100.DAT ' ••• CONTINUITY CHECK FOR SUBCATCHMEMT ROUTING IN UDSWM2-PC MODEL "' ' WATERSHED AREA (ACRES) 3195.200 TOTAL RAINFALL (INCHES) 3.669 TOTAL INFILTRATION (INCHES) .591 ' TOTAL WATERSHED OUTFLOW (INCHES) 2.880 TOTAL SURFACE STORAGE AT END OF STROM (INCHES) .198 ERROR IN CONTINUITY, PERCENTAGE OF RAINFALL .000 FOOTHILLS BASIN - FULLY DEVELOPED CONDITION WITH REVISED RAINFALL 100-YEAR EVENT CITY MODIFIED ACE 99 PONDS 57 6 157 RATING CURVES FOR HOMESTATE SUBMITTAL 11-2000 FILENAME FOOT100.DAT WIDTH INVERT SIDE SLOPES OVERBANK/SURCHARGE GUTTER GUTTER NDP NP OR DIAM LENGTH SLOPE HORIZ TO VERT MANNING DEPTH JK NUMBER CONNECTION (FT) (FT) (FT/FT) L R N (FT) ' 400 156 0 4 CHANNEL .0 800. .0070 50.0 50.0 .016 .40 0 OVERFLOW 40.0 800. .0070 10.0 10.0 .035 2.00 156 102 0 5 PIPE 1.5 780. .0100 .0 .0 .013 1.50 0 OVERFLOW 36.0 780. .0100 50.0 50.0 .016 10.00 ' 163 102 0 4 CHANNEL .0 1800. .0110 .0 50.0 .035 .70 0 OVERFLOW 35.0 1800. .0110 .0 10.0 .035 2.00 401 163 0 4 CHANNEL .0 1200. .0040 50.0 50.0 .016 .40 0 OVERFLOW 40.0 1200. .0040 10.0 10.0 .035 2.00 410 102 2 2 PIPE - .1 1000. .0010 .0 .0 .013 .10 0 RESERVOIR STORAGE IN ACRE-FEET VS SPILLWAY OUTFLOW .0 .0 2.9 2.8 102 154 9 2 PIPE .1 1. .0010 .0 .0 .013 .10 0 RESERVOIR STORAGE IN ACRE-FEET VS SPILLWAY OUTFLOW .0 .0 1.5 1.6 3.7 1.8 6.6 2.1 10.3 2.3 14.4 2.5 17.5 2.6 19.8 2.7 22.9 21.1 ' 154 153 0 5 PIPE 1.3 418. .0040 .0 .0 .013 1.25 0 OVERFLOW .0 418. .0040 50.0 50.0 .016 5.00 413 153 2 2 PIPE .1 1000. .0010 .0 .0 .013 .10 0 RESERVOIR STORAGE IN ACRE-FEET VS SPILLWAY OUTFLOW .0 .0 1.9 1.5 ENVIRONMENTAL PROTECTION AGENCY - STORM WATER MANAGEMENT MODEL - VERSION PC.1 DEVELOPED BY METCALF , EDDY, INC. UNIVERSITY OF FLORIDA WATER RESOURCES ENGINEEERS, INC. (SEPTEMBER 1970) UPDATED BY UNIVERSITY OF FLORIDA (JUNE 1973) HYDROLOGIC 'ENGINEERING CENTER, CORPS OF ENGINEERS MISSOURI RIVER DIVISION, CORPS OF ENGINEERS (SEPTEMBER 1974) BOYLE E.YGIYEERING CORPORATION (MARCH 1985, JULY 1985) TAPE OR DISK ASSIGNMENTS JIN(1) JIN(2) JIN(3) JIN(4) JIN(5) JIN(6) JIN(7) JIN(8) JIN(9) JIN(10) 2 1 0 0 0 0 0 0 0 0 JOUT(1) JOUT(2) JOUT(3) JOUT(4) JOUT(5) JOUT(6) JOUT(7) JOUT(8) JOUT(9) JOUT(10) 1 2 0 -0 0 0 0 0 0 0 NSCRAT(1) NSCRAT(2) NSCRAT(3) NSCRAT(4) NSCRAT(5) 3 4 0 0 0 WATERSHED 1/PROGRAM CALLED ... ENTRY MADE TO RUNOFF MODEL •" FOOTHILLS BASIN - FULLY DEVELOPED CONDITION WITH REVISED RAINFALL 100-YEAR EVENT CITY MODIFIED ACE 99 PONDS 57 & 157 RATING CURVES FOR HOMESTATE SUBMITTAL 11-2000 FILENAME FOOT100.DAT NUMBER OF TIME STEPS 480 ' I.NTEGRATION TIME INTERVAL (MINUTES) 1.00 1.0 PERCENT OF IMPERVIOUS AREA HAS ZERO DETENTION DEPTH FOR 24 RAINFALL STEPS, THE TIME INTERVAL IS 5.00 MINUTES FOR RAINGAGE NUMBER 1 RAINFALL HISTORY IN INCHES PER HOUR ' 1.00 1.14 1.33 2.23 2.84 5.49 9.95 4.12 2.48 1.46 1.22 1.06 1.00 .95 .91 .87 .84 .81 .78 .75 .73 .71 .69 .67 FOOTHILLS BASIN - FULLY DEVELOPED CONDITION WITH REVISED RAINFALL 100-YEAR EVENT CITY MODIFIED ACE 99 PONDS 57 6 157 RATING CURVES FOR HOMESTATE SUBMITTAL 11-2000 FILENAME FOOT100.DAT SUBAREA GUTTER WIDTH AREA PERCENT SLOPE NUMBER OR MANHOLE (FT) (AC) IMPERV. (FT/FT) -2 0 .0 .0 .0 .0300 70 400 3100.0 20.0 18.0 .0110 71 401 6300.0 47.8 19.0 .0120 2 102 4000.0 29.0 38.0 .0100 3 410 1600.0 14.5 40.0 .0130 75 413 2584.0 8.9 40.0 .0120 4 152 2500.0 37.4 17.0 .0090 78 - 104 1710.0 5.5 53.0 .0070 105 7 1500.0 7.5 40.0 .0210 5 201 1700.0 7.8 90.0 .0100 6 8 4000.0 32:1 70.0 .0070 7 9 1300.0 10.0 40.0 .0100 8 11 3000.0 28.3 40.0 .0050 10 14 6400.0 73.8 40.0 .0110 11 16 5600.0 53.0 40.0 .0100 12 18 7000.0 64.9. 28.0 .0030 13 12 1400.0 7.3 10.0 .0120 14 26 1000.0 5.3 40.0 .0130 15 29 2600.0 12.3 10.0 .0400 16 98 1400.0 11.8 90.0 .0100 17 24 1050.0 4.6 80.0 .0150 18 25 2000.0 20.1 80.0 .0050 19 27 2000.0 16.3 90.0 .0080 22 129 3200.0 26.0 90.0 .0090 24 33 3900.0 40.5 40.0 .0100 25 34 6700.0 87.5 90.0 .0150 26 35 3000.0 35.5 50.0 .0100 27 36 1100.0 11.6 50.0 .0100 28 37 725.0 5.0 50.0 .0400 29 43 5800.0 64.5 50.0 .0090 30 41 3200.0 69.1 21.0 .0100 31 38 5200.0 56.5 40.0 .0100 32 42 1400.0 26.9 27.0 .0080 33 48 365.0 2.7 90.0 .0070 34 45 1700.0 16.5 90.0 .0200 RESISTANCE FACTOR SURFACE STORAGE(IN) IMPERV. PERV. IMPERV. PERV. .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 .016 .250 .100 .300 INFILTRATION RATE(IN/HR) GAGE MAXIMUM MINIMUM DECAY RATE NO .51 .50 .00180 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 .51 .50 .00180 1 St Gn Anion 1 n r C ^tit � 1 I t F ( L;;j i y rt gyp. 4l✓ h: LAKE CJHER Al, ... r _ R � A �f i '. t i✓ •tu T 1 � 9L ti d 4 .., 3y">. x3 r, 'h'1T; } t. k TO ar ` m 4E . t' ✓ Z 50 .. CC. ti t ' Y } 1791 Q°F7 53 }» 3. -_x • .t s X, IVC APPENDIX F EXCERPTS FROM FOOTHILLS BASIN MASTER PLAN F CONSTRUCTION SEQUENCE STANDARD FORM C PROJECT: EASTBROOK OFFICE PARK COMPLETED BY: MO DATE: 2 B O6 Indicate by use of a bar line or symbols when erosion control measures will be installed. Major modifications to on approved schedule may require resubmitting a new schedule for approval by the City Engineer. 006 2007 MONTH JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY 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 Bore Soil Preparation Contour Furrows Terracing Asphalt/Concrete Paving Other Vegetative: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting Sod Installation N ett in g s/Mats/Blankets Other BUILDING CONSTRUCTION STRUCTURES: INSTALLED BY: CONTRACTOR MAINTAINED BY: VEGETATION/MULCHING CONTRACTOR: TO BE DETERMINED BY BID DATE SUBMITTED: - APPROVED BY CITY OF FORT COLLINS ON: r O Cost Est EROSION CONTROL COST ESTIMATE Project: EASTBROOK Prepared by: MPO ITEM IQUANTITY JUNIT COST/UNIT ITOT=T Silt Fence 1130 LF $3 $3,396 Straw Bale Barrier 4 EA $150 $600 Inlet Protection 8 EA $150 $1,200 Construction Entrance 1 EA $550 $550 Subtotal Contingency (50%) Total $5,740 $2,870 $8,610 CITY RESEEDING COST Reseed/Mulch 3.9 ACRE 1 $650 $2,535 Subtotal Contingency (50%) Total $2,535 $1,268 $3,803 EROSION CONTROL ESCROW AMOUNT $8,610 Page 1 North Star Design 700 Automation Dr. Unit I Windsor, CO 80550 EFFECTIVENESS CALCULATIONS PROJECT: EASTBROOK STANDARD FORM B COMPLETED BY: JIPO DATE: 09-Feb-06 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 SEDINIENT BASIN 1.00 0.90.4- ROADS/WALKS 0.01 <— 1.00 GRAVEL FILTERS 1.00 0.80 PLACED AT INLETS SILT FENCE 1.00 0.50 STRAW MULCH 0.06 L00 ESTABLISHED GRASS 0.084 1.00 STRAW BARRIERS 1.00 0.80 EFF= (I-C*P)*100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN (Ac) -} Z I , I AC-. Z, ? NG. IZoAD / f Z. q c,0 1 j -+-i0. ^G `� o85 O. S AwTo W� �Q tom-. O.S co TOTAL AREA = 3 Z q-(r , TOTAL EFF = c;kp d�7p REQUIRED PS = g 7`� B'.J Erosion.xis 1 of 1 North Star Design 700 Automation Dr. Unit I Windsor, CO 80550 EFFECTIVENESS CALCULATIONS - ��(�G Gt-)STZOCTIZ:) I PROJECT: EASTBROOK STANDARD FORM B COMPLETED BY: INIPO DATE: 09-Feb-06 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 SEDIMENT BASIN 1.00 0.50 4�— ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 PLACED AT INLETS SILT FENCE 1.00 0504— STRAW MULCH 0.06 46— 1.00 ESTABLISHED GRASS 0.08 1.00 STRAW BARRIERS 1.00 0.80 EFF = (I-C'P)' 100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN BASIN (Ac) 3,2-�s Aw 98, TOTAL AREA = 3, Z 4 C. TOTAL EFF = REQUIRED PS = 757, �p Erosion.xls 1 of 1 APPENDIX E EROSION CONTROL CALCULATIONS rol rTi" STANDARD CHANNEL K BY D I4 BARS AT W DC WELL -SCREEN MAME ATTACHED TO RATE BY INTERMITTENT WELDS STRUCTURAL STEEL CHANNEL BF I 3- CLEAR — TYP I 3- CLEAR J TYP. /4 BARS AT 8- OC' #1 BARS AT Y 3B'-D" A n ELEVATION VIEW x ms STAINLESS STEEL BOLTS OR INTERMITTENT WELDS r GROUND ADJACENT TO WALL 2" STAINLESS STEEL WELL -FLOW I� SCREEN ATTACHED BY INTERMITTENT WELDS ALL AROUND SECTION S-B NOT TO SCALE WATER QUALITY OUTLET STRUCTURE N.T.S. B POND INV. EIEV 491 20 I BOTTOM WALL mEw38.70 — — — — — j _ CONCRETE HEADWALL WITH WARR QUALITY STRUCTURE Emergency Overflow Spillway Sizing LOCATION: EASTBROOK OFFICE PARK PROJECT NO: 265-01 COMPUTATIONS BY: MPO SUBMITTED BY: NORTH STAR DESIGN DATE: 02/09/2006 Equation for flow over a broad crested weir to of berm Q = CLH3/2 — H+ where C = weir coefficient = 2.6 4 Spill 44evation H =overflow height �— � � L = length of the weir 100 WSEL The pond has a spill elevation 0.0 ft above the maximum water surface elevation in the pond Spillways will be designed with 0.7 ft max flow depth, thus H = 0.7 ft Q (100) = 27.1 cfs Spill elev = 4942.80 ft Min top of berm elev.= 4943.50 Weir length required: L= 18 ft Use L = 26 ft v = 1.34 ft/s 100 yr WSEL = 4942.60 ft ACTUAL DEPTH = 0.54 ft SPILLWAY.xls PROPOSED POND VOLUME LOCATION: EASTBROOK OFFICE PARK PROJECT NO: 265-01 COMPUTATIONS BY: MPO SUBMITTED BY: North Star Design DATE: 02/08/2006 Water quality required = 0.088 ac-ft 100-Year Detention Required = 0.000 ac-ft Total Detention Required = 0.088 ac-ft Water Quality WSEL Spillway Top of Berm Stage (ft) Surface Area (ft') Incremental Storage (ac-ft) Detention Storage (ac-ft) Total Storage (ac-ft) 4940.2 0 0.000 4940.5 100 0.000 0.000 4941.0 800 0.005 0.005 4941.5 1700 0.014 0.019 4942.0 2500 0.024 0.043 4942.5 3600 0.035 0.078 4942.6 4104 0.011 0.088 4942.8 4860 0.018 0.107 4943.0 5700 0.024 0.131 4943.5 9700 0.087 0.218 II Design Procedure form: Extended Detention Basin . (EDB) : Sedimentation Facility Sheet 1 of 3 Designer: MPO Company: NORTH STAR DESIGN Date: February 8, 2006 Project: EASTBROOK OFFICE PARK Location: 1. Basin Storage Volume A) Tributary Area's Imperviousness Ratio (i = 1, / 100 ) B) Contributing Watershed Area (Area) C) Water Quality Capture Volume (WQCV) (WQCV =1.0-(0.91'1'-1.19'1`+0.78.1)) D) Design Volume: Vol = (WQCV 112)' Area' 1.2 2. Outlet Works A) Outlet Type (Check One) B) Depth at Outlet Above Lowest Perforation (H) C) Required Maximum Outlet Area per Row, (Ac) D) Perforation Dimensions (enter one only): i) Circular Perforation Diameter OR ii) 2" Height Rectangular Perforation Width E) Number of Columns (nc, See Table 6a-1 For Maximum) F) Actual Design Outlet Area per Row (Ao) G) Number of Rows (nr) H) Total Outlet Area (A.J 3. Trash Rack A) Needed Open Area: A, = 0.5 • (Figure 7 Value)' Ao� B) Type of Outlet Opening (Check One) C) For 2", or Smaller, Round Opening (Ref.: Figure 6a): i) Width of Trash Rack and Concrete Opening (Wwnc) from Table 6a-1 ii) Height of Trash Rack Screen (HTR) la = 70.00 % i = 0.70 Area = 3.20 acresfji I Z WQCV = 0.28 watershed inches Vol =;..: 0.088 - acre-feet X Orifice Plate Perforated Riser Pipe Other: H = 2.40 feet An= -0:15-:. square inches / / 1 LIP D = 0.438 inches, OR � W = inches nc :"7 e number Ao -.. `�."'O.15,"' square inches nr , _�7 =;number A01 =�1 08 '- , square inches '393. square inches X < 2" Diameter Round 2" High Rectangular Other: Wwnc= . ":.3,.:...'': inches HTR= 59...• inches USDCM VOL 3 BMP Design Forms v2.03 (20030121).xls, EDB 02/09/2006, 2:47 PM APPENDIX D WATER QUALITY POND SIZING N 0+00 0+50 Label; P-1 Up. Invert: 41.60 It Dn. Invert: 41.00 it L: 62.30 t Size: 15 inch S:0.009631 fit/ft Profile Scenario: Base Label: J-2 Rim: 45.70 ft Label: J-3 Sump: 4 2.50 ft Rim: 46.30 ft Sump: 43.20 ft L... .. ..... .... . 1+00 1+50 SiNo% (it) Label: P-2 Up. Invert: 42.50 it Dn. In ve rt: 41.6 0 ft L: 140.04 ft Size: 15 inch S: 0.006427 fit/ft 2+50 3+00 Label: P-3 Up. Invert: 43.20 It Dn. Invert: 42.50 it L: 112.00 ft Size: 15 inch S: 0.006250 ft/ft Label: J-6 Label: 1-2 Rim: 46.00 ft Rim: 46.00 ft Sump: 43.30 it Sump: 4 3.50 ft 46.50 45.00 44.00 Elevation (it) 43.00 42.00 41.00 3+50 4+00 Label: P-7 Label: P-8 Up. Invert: 43.30 it Up. invert: 43.50 lt Dn. In vc it: 43.20 it Dn. Invert: 43.30 It L: 15.96 it L: 46.50 It Size: 12 inch Size: 12 inch S: 0.0 06 266 ft/ft S: 0.0 04 301 ft/ft Title: EASTBROOK Project Engineer: MPO n:\265-01 eastbrook\dranage\eastbrook.stm North Star Design, Inc. StormCAD v4.1.1 [4.2014] 02/08106 10:53:11 AM Q Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Profile Scenario: Base Label: ai Label: J-1 Rim:42.80 It Surrp: 41.00 R Rim:45.70 ft Surrp: 41.60 R y - O+rOO 0+00 7 0+50 1+00 Label: t-3 Rim: 47.50 It Surrp: 45.00 R 48.00 47.00 46.00 45.00 Elevation (ft) 44.00 43.00 42.00 41.00 4+00 4+50 Label: P-1 Label: P-2 label: P-3 Label: P-9 Up. Invert 41.60 R Up. Invert 42.50 R Up. Invert 4320 It Up. Invert 45.00 ft Dn. Invert 41.00 R Dn. Invert 41.60 ft Dn. Invert 42.50 R Dn. Invert 4320 ft L 62.30 R L 140.04 It L 112.00 R L 86.52 R Sze: 15 inch Size: 15 inch Size: 15 inch Size: 12 inch S: 0.009631 fUft S: 0.006427 fft S: 0.006250 fhft S: 0.020804 ftRt Title: EASTBROOK Project Engineer: MPO n:\265-01 eastbrook\dranage\eastbrook.stm North Star Design, Inc. StormCAD v4.1.1 [4.2014] 02/08/06 10:53:50 AM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Label: P-1 Lip. Invert 41.60 It Dn. Invert 41.00 It L 62.30 ft Size: 15 inch S: 0.009631 Nft Label: P-2 Up. Invert 4250 It Dn. Invert 41.60 ft L 140.04 It Size: 15 inch S: 0.006427 t t Profile Scenario: Base Lp C; S Labe: J-2 Labe: J3 Rim 46.30 ft Label: J-4 Label: J-5 label: 1-1 Rim 45.70 ft Sung: 42.50ft Surrp: 4320ft Rim 46.00 ft Surrp: 43.30 ft Rim 46.00 It Sump: 43.40 ft Rim 46.00 ft Sunp: 43.50ft ._. __ ,._ _..... . _... _.. _._.... _.........., __ __.. . 46.50 .............. Elevation (ft) 44.00 ....... .. ..... _ .. 43.00 - 42.00 :..__ _...... ............. _........... -................ ............ __ ...... ... _ .... .... 41.00 2+00 Station (ft) 2+50 3+00 3+50 4+00 4 �O Label: P-3 Up. Invert 43.20 It On. Invert 4250 It L 112.00 It Size: 15 inch S 0+006250 Rift Label: P-4 Up. Invert 43.30 ft Dn. Invert 43.20 It L 34.09 ft Size: 12 inch S: 0.002933 M Labe: P-5 Labe: P-6 Up. Invert 43.40 It Lip. Invert 43.50 It Dn. Invert 43.30 It Dn. Invert 43.40 ft L 46.50 ft L 53.50 It Size: 12 inch Size: 12 inch S: 0.002151 Rift S: 0+001869 fbft Title: EASTBROOK Project Engineer: MPO n:\265-01 eastbrook\d ravage\eastbrook.slm North Star Design, Inc. StormCAD v4.1.1 [4.2014] 02/08/06 10:50:03 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Scenario: Base PipeWode Report Label Number Of Sections UpstrearrDownstrean Node Node Section Size Length (ft) Slope (ft/ft) System Flow (cfs) Full Capacity (cfs) Average Velocity (ft/s) Upstream Invert (ft) Downstream Invert (ft) Upstream Crown (ft) Downstream Crown (ft) Hydraulic Grade Line In (ft) Hydraulic Grade Line Out (ft) P-1 1 J-1 0-1 15 inch 62.30 0.009631 7.00 6.34 6.05 41.60 41.00 42.85 42.25 42.80 42.06 P-2 1 J-2 J-1 15 inch 140.04 0.006427 7.00 6.73 5.70 42.50 41.60 43.75 42.85 44.08 43.11 P-3 1 J-3 J-2 15 inch 112.00 0.006250 7.00 6.64 5.70 43.20 42.50 44.45 43.75 45.16 44.39 P-4 1 J-4 J-3 12 inch 34.09 0.002933 2.00 2.51 2.55 43.30 43.20 44.30 44.20 45.53 45.47 P-5 1 J-5 J-4 12 inch 46.50 0.002151 2.00 2.15 2.55 43.40 43.30 44.40 44.30 45.68 45.59 P-6 1 1-1 J-5 12 inch 53.50 0.001869 2.00 2.00 2.55 43.50 43.40 44.50 44.40 45.84 45.74 P-7 1 J-6 J-3 12 inch 15.96 0.006266 2.00 3.67 2.55 43.30 43.20 44.30 44.20 45.50 45.47 P-8 1 1-2 J-6 12 inch 46.50 0.004301 2.00 3.04 2.55 43.50 43.30 44.50 44.30 45.65 45.56 P-9 1 1-3 J-3 12 inch 1 86.52 0.020804 3.001 6.6814.311 45.001 43.201 46.001 44.201 45.74 45.47 Title: EASTBROOK n:\265-01 eastbrook\dranage\eastbrook.stm Project Engineer: MPO - North Star Design, Inc. StormCAD V4.1.1 [4.20141 02/08/06 10:54:38 AM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Scenario: Base a1 J-1 P-2 J-2 1-2 P-8 P-7 J -3 P-4 J-4 P-5 J-5 P-6 I-1 _ E J-6 1-3 Title: EASTBROOK Project Engineer: MPO n:\265-01 eastbrook\dranage\eastbrook.stm North Star Design, Inc. StormCAD v4.1.1 [4.2014] 02/08/06 10:54:10 AM 0 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 APPENDIX C HYDRAULIC CALCULATIONS A North Star Design, Inc. 700 Automation Drive, Unit I Windsor, CO 80550 LOCATION: PROJECT NO: COMPUTATIONS BY DATE: 100-yr storm, Cf = RATIONAL METHOD PEAK RUNOFF (NEW IDF CURVE) (100-YEAR) EASTBROOK OFFICE PARK 265-01 MPO 02/09/2006 1.25 �&DIRECT RUNOFF Q=CiA Q = peak discharge (cfs) C = runoff coefficient I = rainfall intensity (in/hr) from IDF curve A = drainage area (acres) NOTE: Intensity based on Figure 3-1, 1999 (Regional Analysis) Fiow.xls Q100 North Star Design, Inc. 700 Automation Drive, Unit I Windsor, CO 80550 LOCATION: PROJECT NO: COMPUTATIONS BY: DATE: 10-yr storm, Cf = RATIONAL METHOD PEAK RUNOFF (NEW IDF CURVE) (10-YEAR) EASTBROOK OFFICE PARK 265-01 MPO 02/09/2006 1.00 �&DIREGT RUNOFF•, ---------- Q=C,CiA Q = peak discharge (cfs) C = runoff coefficient Ct = frequency adjustment factor I = rainfall intensity (in/hr) from IDF curve A = drainage area (acres) NOTE: Intensity based on Figure 3-1. 1999 (Regional Analysis) FlowAs Q10 North Star Design, Inc. 700 Automation Drive, Unit I Windsor. CO 80550 LOCATION: PROJECT NO: COMPUTATIONS BY: DATE: 2, yr storm, Cf = RATIONAL METHOD PEAK RUNOFF (NEW IDF CURVE) (2-YEAR) EASTBROOK OFFICE PARK 265-01 MPO 02/09/2006 1.00 DIRECT Q=CfCiA Q = peak discharge (cfs) C = runoff coefficient Cf = frequency adjustment factor I = rainfall intensity (in/hr) from IDF curve A = drainage area (acres) NOTE: Intensity based on Figure 3-1, 1999 (Regional Analysis) Flow.xls 02 North Star Design, Inc. 700 Automation Drive, Unit I Windsor, CO 80550 LOCATION: PROJECT NO: COMPUTATIONS BY: DATE: 100-yr storm Cf = EASTBROOK OFFICE PARK 265-01 MPO 02/09/2006 1.25 STANDARD FORM SF-2 TIME OF CONCENTRATION - 100 YR SUB -BASIN DATA DESIGN SUBBASIN(s) Area POINT (ac) (1) (2) INITIAL /OVERLAND TIME (If) C C'C1 Length Slope ti III) (%) (min) (3) (4) (5) (6) TRAVEL TIME / GUTTER OR CHANNEL FLOW (tt) Length Slope n Vel. tt tc = (ft) (%) Manning. (ft/s) (min) ti«tt (7) (8) rough. (9) (10) (11) tc CHECK (URBANIZED BASIN) Total L tc=(1/180)+10 (ft) (min) (12) (13) FINAL tc (min) (14) REMARKS 1 2 3 0.86 2.34 0.67 0.79 0.74 0.45 0.99 0.93 0.56 70 40 20 2.0 2.5 2.0 1.4 1.4 3.4 180 580 390 1.60 0.80 1.50 0.016 0.016 0.016 2.51 1.8 2.5 1.18 5.38 2.64 2.6 6.8 6.1 250 620 410 11.4 13.4 12.3 5,0 6.8 6.1 1 «2 3.20 0.76 0.94 40 2.5 1.3 580 0.80 0.016 1.8 5.38 6.7 620 13.4 6.7 EQUATIONS: tc=ti+tt ti=(1.87(1.1-CC1)Lo.e]/S1/3 tt = L/Vel. Velocity from Manning's Equation with R=0.1 (corresponds to Figure 3-3 of City of Fort Collins Design Manual) final tc = minimum of ti + tt and urbanized basin check min. tc = 5 min. due to limits of OF curves Flow.xls TOC-100 North Star Design, Inc. 700 Automation Drive, Unit I Windsor. CO 80550 STANDARD FORM SF-2 TIME OF CONCENTRATION - 10 YEAR LOCATION: EASTBROOK OFFICE PARK PROJECTNO: 265-01 COMPUTATIONS BY: MPO DATE: 02/09/2006 10-yr storm Cf = 1.00 SUB -BASIN DATA INITIAL /OVERLAND TIME (b) TRAVEL TIME / GUTTER OR CHANNEL FLOW (tt) tc CHECK (URBANIZED BASIN) FINAL tc REMARKS DESIGN POINT SUBBASIN(s) (1) Area (ac) (2) C (3) Length (fl) (4) Slope (%) (5) ti (min) 1 (6) Length (fl) (7) Slope (%) (8) n Manning rough. Vel, (ft/s) (9) It (min) (10) tc = ti+It (11) Total L (fl) (12) tc=(1/180)+10 (min) (13) (ruin) (14) 1 0.86 0.79 701 2.0 3.7 1801 1.60 0.0161 2.5 1,18 4.9 250 11.4 5.0 2 2.34 0.74 401 2.5 3.0 580 0.80 0.0161 1.8 5,38 8.4 620 13.4 8A 3 0.67 0.45 201 2.0 4.1 390 1.50 0.0161 2.5 2,64 6.8 410 12.3 6.8 1+2 3.20 0.76 401 2.5 2.9 580 0.80 0.0161 1.8 5.38 8.3 620 13.4 8.3 EQUATIONS: tc = ti + It tl=(1.87(1.1-CCt)Lo.5)iS1/3 tt = LA7el. Velocity from Manning's Equation with R=0.1 (corresponds to Figure 3-3 of City of Fort Collins Design Manual) final tc = minimum of ti + tt and urbanized basin check min. tc = 5 min, due to limits of IDF curves Flow.xls TOC-10 North Star Design, Inc. 700 Automation Drive, Unit I Windsor, CO 80550 RUNOFF COEFFICIENTS 8 °/n IMPERVIOUS LOCATION: EAS'I'BROOKOFFICE PARK PROJECT NO: 265-01 CONIPUTATIONS BY: MPO DXI'E: 02/09/2006 Recommended Runoff Coefficients from Table 3-3 of City of Fort Collins Design Criteria Recommended % Impervious from Urban Storm Drainage Criteria Manual Streets, parking lots (asphalt) Concrete Roofs Gravel Lawns (flat <2%, heavy soil) Runoff coefficient C % Impervious 0.95 100 0.95 96 0.95 90 0.50 40 0.20 1 0 SUBBASIN DESIGNATION TOTAL AREA (ac.) TOTAL AREA (sq.ft) PAVED AREA (sq.ft) CONCRETE AREA (sq.ft) ROOF AREA (sq.ft) GRAVEL AREA (sq. ft) LANDSCAPE AREA (sq. ft) RUNOFF COEFF. (C) % Impervious REMARKS 1 0.86 37.500 0 3,000 26.400 0 8.100 0.79 71 2 2.34 102,000 47,500 6.500 19.900 0 28.100 0.74 70 3 0.67 29,200 7,300 2.500 0 0 19,400 0.45 33 1+2 3.20 139,500 47,500 9,500 1 46,300 0 36,200 0,76 70 1+2+3 3.87 168,700 54,800 12,000 46,300 0 55.600 0,70 64 Equations - Calculated C coefficients & % Impervious are area weighted C=E(Ci Ai) /At Ci = runoff coefficient for specific area, Ai Ai = areas of surface with runoff coefficient of Ci n = number of different surfaces to consider At = total area over which C is applicable; the sum of all Ai s Flow.xls Cval ' APPENDIX B HYDROLOGIC COMPUTATIONS ' PROJECT LOCATION VICINITY MAP SCALE: 1" = 1.000' APPENDIX A VICINITY MAP A are to be kept in a roughened condition and watered to reduce wind erosion. The water quality pond will be used as a sediment trap during construction. 6. CONCLUSIONS 6.1 Compliance with Standards All computations that have been completed within this report are in compliance with the ' City of Fort Collins Erosion Control Reference Manual for Construction Sites and the Storm Drainage Design Criteria Manual. Requirements placed on the site related to the ' new rainfall criteria have been followed. The site is 64% impervious (which meets the Master Plan model). No variances are ' required for the project. ' 6.2 Drainage Concept ' The proposed drainage concepts presented in this report and on the construction plans . adequately provide for stormwater quality treatment of proposed impervious areas. Conveyance elements have been designed to pass required flows and to minimize future ' maintenance. ' If, at the time of construction, groundwater is encountered, a Colorado Department of Health Construction Dewatering Permit will be required. 7. REFERENCES 1. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March, 1986. 2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria ' Manual", Volumes 1 and 2, dated June 2001, and Volume 3 dated September 1999. 5 been designed to overtop a concrete spillway in large storms and does not have a pipe ' outlet. The pond is slightly oversized and meets City criteria. ' Basin 3 includes the far west and east portions of the site as well as the adjacent half right of way of Eastbrook Drive. This basin has been extended to the centerline of the street in order to demonstrate that the site as modeled in the Master Plan meets the maximum 65% ' impervious percentage. t4.3 Drainage Summary Drainage facilities located outside of the right of way (including the water quality pond, proposed storm drain system and the pond outlet) will be maintained by the owners of the property 5. EROSION CONTROL 5.1 General Concept ■ This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort Collins Zone Maps. The potential exists for silt movement from the siteand into the ' existing drainage areas on the west and north sides of the site. Potential also exists for tracking of mud onto existing streets which could then wash into existing storm systems. ' The required performance standard for the site is 75.6%. During construction and after final paving and building construction, this figure has been exceeded with the use of silt ' fence, straw bales and by using the water quality pond and a sediment trap during construction. ' The erosion control escrow amount is $8,610. 5.2 Specific Details To limit the amount of silt leaving the site several erosion control measures shall be implemented during construction. Straw bales will be used where appropriate, and the north, east and west boundaries shall have silt fence installed. A vehicle tracking pads ' shall be installed at the proposed north drive connection to Eastbrook Drive to control the mud being tracked onto the existing pavement. During overlot grading, disturbed areas ' 4 ' 3.4 Hydraulic Criteria ' All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are included in Appendix C of this report. ' 4. DRAINAGE FACILITY DESIGN 4.1 General Concept ' The majority of the proposed development will be routed via sheet and gutter flow to the proposed water quality pond in the northwest corner of the site. The pond releases to the north. There is a small portion of the east side of the site that will sheet flow to Eastbrook Drive. 4.2 Specific Flow Routing A summary of the drainage patterns within each basin is provided in the following paragraphs. Basin 1 includes the central portion of the site. The site has been designed with four ' buildings and a perimeter drive and parking area. The design attempts to keep all four buildings as close to the same finished floor elevation as possible. With this building ' configuration and grading design, it is difficult to get water to drain overland to the perimeter drive areas. This basin includes the areas (mostly roof) that are assumed to drain to the landscaping between the buildings. A small storm sewer system has been ' designed to accept flows from roof drains and the areas between the buildings. This system has been designed for about 6 cfs, which is less than the 100 year flow, but all of ' the areas, if inundated, will overtop to adjacent sidewalks and drives without flooding the buildings. The storm sewer system is not intended to take all of the major storm, but ' should easily take minor storm flows. Because this system is mainly for small storms, the 8 ADS inlets provided have not been sized. Again, if they are overwhelmed, flows will overtop to the drives and not get to the building floor elevations. Basin 2 includes the majority of the site. It includes all of the parking and drive areas, ' much of the building area, and the water quality pond. This basin drains west and north in the gutters to two curb cuts and into the water quality pond. The water quality pond has ' 3 ' In the Foothills Basin Master Plan, this site is in SWMM Basin 50. This basin was ' modeled with an imperviousness of 65%. Because of the large drainage area north of this site and the railroad right of way both having a very small impervious percentage, the 65% ' design figure is likely quite high. The proposed project meets the 65% impervious percentage and will not be required to provide Stormwater quantity detention. 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage Design Criteria Manual' specifications. Where applicable, the criteria established in the "Urban Storm Drainage Criteria Manual" (UDFCD), developed by the Denver Regional Council of Governments, has been used. 3.2 Development Criteria Reference and Constraints The runoff from this site has been routed to conform to the requirements of the City Stormwater Department. The site is not required to provide Stormwater detention as long as the Master Plan impervious percentage is not increased. Water quality facilities are required for the new construction proposed on the site. 3.3 Hydrologic Criteria Runoff computations were prepared for the 10-year minor and 100-year major storm ' frequency utilizing the rational method. ' All hydrologic calculations associated with the basins are included in Appendix B of this report. Standard Form 8 (SF-8) provides time of concentration calculations for all sub - basins. Standard Form 9 (SF-9) provides a summary of the design flows for all Sub -basins ' and Design Points associated with this site. ' Water quality volume was calculated using the method recommended in the "Urban Storm Drainage Criteria Manual'. GENERAL LOCATION AND DESCRIPTION ' 1.1 Location Eastbrook Office Park is located in southeast Fort Collins. The project includes Lot 2 and the south portion of Lot 4, New Hampshire Subdivision. It is located in the southeast quarter of Section 30, Township 7 North, Range 68 West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. See the location map in Appendix A. The project is located west of Eastbrook Drive and east of the Union Pacific Railroad. A ' large drainage easement is located on the north side of the property (on the remaining portion of Lot 4) and an office building is south of the site. ' 1.2 Description of Property ' The entire project consists of approximately 3.6 acres of land, all of which will undergo grading and other construction activity. Four "flex" office buildings are proposed for the site with associated parking and drives. The land. currently slopes to the north at approximately 2%. There is an existing swale west of the property (in the UP Right of ' Way), there is a larger drainage channel and easement north of the property, and there is a very shallow drainage swale on the east side of the property. The swale on the east drains the lot to the south (Lot 1). This swale presently drains north within the property and then over the existing walk and curb and into Eastbrook Drive. There are no mapped floodplains on the property. 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description ' The proposed development lies within the Foothills Master Drainage Basin. ' 2.2 Sub -basin Description This site drains north to the existing drainage easement north of the site. This drainage path will be maintained with the development of this site. TABLE OF CONTENTS TABLEOF CONTENTS............................................................................................................ in 1. GENERAL LOCATION AND DESCRIPTION ' 1.1 Location...............................................................................................................1 1.2 Description of Property........................................................................................I ' 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description.......................................................................................1 2.2 Sub -Basin Description.......................................................................................... I j 3. DRAINAGE DESIGN CRITERIA ' 3.1 Regulations.......................................................................................................... 2 3.2 Development Criteria Reference and Constraints .................................................. 2 3.3 Hydrologic Criteria.............................................................................................. 2 ' 3.4 Hydraulic Criteria................................................................................................. 3 4. DRAINAGE FACILITY DESIGN ' .4.1 General Concept.................................................................................................. 3 4.2 Specific Flow Routing........................................................................................... 3 4.3 Drainage Summary ...............................................................................................4 5. EROSION CONTROL 5.1 General Concept.................................................................................................4 5.2 Specific Details.................................................................................................... 4 6. CONCLUSIONS ' 6.1 Compliance with Standards................................................................................. 5 6.2 Drainage Concept................................................................................................ 5 7. REFERENCES................................................................................................................5 APPENDICES A Vicinity Map ' B Hydrologic Computations C Hydraulic Calculations D Water Quality Pond Sizing ' E Erosion Control Calculations F Excerpts from Foothills Basin Master Plan ' G Figures and Tables North Star �amow design, inc. February 14, 2006 Basil Hamdan City of Fort Collins Stormwater 700 Wood Street Fort Collins, CO 80522-0580 RE: Final Drainage and Erosion Control Report for Eastbrook Office Park Dear Basil, I am pleased to submit for your review and approval, this revised Final Drainage and Erosion Control Report for Eastbrook Office Park. I certify that this report for the drainage design was prepared in accordance with the criteria in the City of Fort Collins Storm Drainage Manual. I appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. �p0 pEp � Sincerely, o�ls•,..f..,. o Michael Oberlander, P.E., L.S.I. it 700 Automation Drive, Unit I Windsor, Colorado 80550 970-686-6939 Phone 0 970-686-1 188 Fax FINAL DRAINAGE AND EROSION CONTROL REPORT EASTBROOK OFFICE PARK (Lot 2 and a part of Lot 4, New Hampshire Subdivision) Prepared for: Sitzman-Mitchell 3500 JFK Parkway Fort Collins, CO 80525 Prepared by: North Star Design 700 Automation Drive, Unit I Windsor, Colorado 80550 (970)686-6939 February 14, 2006 Job Number 265-0I