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HomeMy WebLinkAboutDrainage Reports - 07/26/2013city offt..Collins ro Puns Approved By Date 2R —1 �. AMENDMENT NO. 1 to the FINAL DRAINAGE AND EROSION CONTROL REPORT Evergreen Park Fourth Filing Kaufman & Robinson, Inc. Fort Collins, Colorado 08-July-2013 Prepared for: Basis Architecture, PC 1692 Big Thompson Avenue, Suite 100 Estes Park, Colorado 80517 Phone: 970.586.9140 Prepared by: Troy W. Campbell, PE Ridgeline Consultants, Inc. 16911 Potts Place Mead, Colorado 80542 Phone: 970.217.9148 RCI Project Number: 0114-1 v, Mead, CO 80542� 9y--I—Consultants, Inc.. ____, ._990:219:9i'4S--Y qG July 8, 2013 Mr. Glen Schlueter City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, CO 80521 RE: Amendment No. 1 to the Final Drainage and Erosion Control Report for Evergreen Park Fourth Filing- Kaufrnan & Robinson, Inc., Fort Collins, Colorado Dear Mr. Schlueter: We are pleased to present this Amendment No. 1 to the Final Drainage and Erosion Control Report for Evergreen Park Fourth Filing - Kaufman & Robinson, Inc., for your review and approval. This Amendment has been prepared in accordance with the City of Fort Collins Storm Drainage Design Criteria (Revised January 1997). The proposed project consists of the following: • Building addition; and, • Parking area expansion south of the building. A possible future phase of development may include: • Parking area expansion on the west side of the site; and, • One (1) building. We look forward to your favorable review of this project and Amendment. Please do not hesitate to contact us if you have any questions. Sincerely, Ridgeline Consultants, Inc. C Troy W. Campbell, PE Project Manager piL�iiT'`TL Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufman & Robinson, Inc. July 8, 2013 Page 2 L GENERAL LOCATION AND DESCRIPTION A. Site Location: The proposed development is located in the northwest quarter of Section 1, Township 7 North, Range 69 West, of the 61h Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. Furthermore, the site is further described as Evergreen Park, Fourth Filing, which is north of Conifer Street, south of Willox Lane and east of College Avenue. More particularly, the proposed site is located at the northeast corner of the intersection of Blue Spruce Drive and Red Cedar Circle. B. Site Description: The entire Kaufman & Robinson, Inc. site consists of approximately 1.75 acres and contains one (1) building, landscaping, sidewalks and associated parking and drive areas and an existing detention pond. The existing on -site slopes range from approximately 0.5% to 2%. Existing ground cover on the lot consists of the above items as well as moderate vegetation, including weeds and grasses. According to the SCS soils map, the native soil in this area is Nunn Clay Loam. Nunn Clay Loam is a Type C soil and according to the SCS, this soil type is classified as well -drained. Refer to the approved Final Drainage and Erosion Control Report - Evergreen Park Fourth Filing, dated March 23, 2010 for additional information. Existing drainage facilities near and adjacent to the site include the existing onsite detention pond (Pond A) as well as concrete curb & gutter, concrete pan and swales. Furthermore, the adjacent property to the north contains an existing detention pond on the east side of that site. This pond was constructed as part of the improvements for Lots 1 &2, Block 5, Replat (No. 1) of Evergreen Park. The existing Evergreen West pond is located east of the proposed site. The existing high water elevation for this pond is approximately 4962.5. C. Proposed Project Description: The proposed Kaufman & Robinson, Inc. Shop Addition development will consist of a building addition, landscaping, and associated parking and drive areas. A future phase of construction may consist of one (1) building and associated parking and drive areas. The detention pond has been redesigned based on these two phases of development. The lots immediately to the north and south have been developed. Each site consists of multiple buildings, landscaping, sidewalks and associated parking and drive areas. RIVULLINE Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufman & Robinson, Inc. July 8, 2013 Page 3 D. Flood Hazard and Relevant Drainage Studies: The proposed site is not located within a FEMA delineated floodplain. The site was removed from the floodplain with the Dry Creek Diversion project improvements. Relevant drainage studies for this area include: • Greenbriar-Evergreen Master Drainage Plan, prepared by Engineering Professionals, Inc. • Final Drainage and Erosion Control Report for Lots 1 & 2, Block S, Replat (No. 1) of Evergreen Park, dated January 1999, prepared by Shear Engineering Corporation. • Final Drainage and Erosion Control Report - Evergreen Park Fourth Filing, dated March 23, 2010, prepared by Ridgeline Consultants, Inc. II. HISTORIC DRAINAGE SYSTEM A. Major Basin: This site is located within the Dry Creek Drainage Basin as shown on the City of Fort Collins Drainage Basin Master Plan, approved by the City Council in June 2004. Furthermore, this area has been analyzed in the reports listed in I.D. above. The basis for the drainage design is the City of Fort Collins Drainage Basin Master Plan conclusions and recommendations. B. Sub -basin and Site Drainage: The runoff from this site currently flows generally from the west/northwest portion of the site to the eastern side of the site to the existing detention pond (Pond A). The detained runoff from this site currently drains into the existing Evergreen West pond, located east of the site. Virtually no off -site runoff enters the proposed site. The lots to the north and south have existing development and conveyances for their site runoff. The drainage patterns proposed with the development of the Kaufman & Robinson Shop Addition and future building are generally consistent with the drainage patterns described in previous studies for the proposed site. p1LVLLIVIL Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufman & Robinson, Inc. Julv 8.2013 III. PROPOSED (DEVELOPED) DRAINAGE SYSTEM 4 A. Criteria: Drainage design is in accordance with the City of Fort Collins Storm Drainage Design Criteria as well as the Urban Drainage and Flood Control District Criteria Manual. There are no deviations from the criteria in this report. The design storms for this project are the 10-year and the 100-year recurrence intervals. Runoff is calculated using the rational method since all basins are smaller than 160 acres. The rational method calculations are computed by the following: Q = CtciA where: Q = Runoff in cubic feet per second Cf = Rational Method frequency adjustment factor c = Calculated runoff coefficient for design event i = Storm intensity in inches/hour A = Basin area in acres Cfis 1.0 for the 10-year storm and 1.25 for the 100-year storm. Furthermore, the product of c times Cfshall not exceed 1.0. Hydrological calculations have been prepared in accordance with the City of Fort Collins Storm Drainage Design Criteria as well as the Urban Drainage and Flood Control District Criteria Manual. B. Runoff: This proposed development is part of the Evergreen Park development. The approved Evergreen Park Drainage Plan & Report, dated June 11, 1973, prepared by VTN Colorado as well as the Final Drainage and Erosion Control Report for Lots 1 & 2, Block 5, Replat (No. 1) of Evergreen Park, dated January 1999, prepared by Sheaf Engineering Corporation, have been reviewed as part of the analysis of the drainage for this site and the recommendations have been incorporated where feasible. Runoff calculations for this site have been completed in accordance with the City of Fort Collins criteria and are included in the Appendix of this Amendment. Runoff will be conveyed via sheet flow, concrete pan, curb & gutter and grass swale to the existing detention pond (Pond A). The runoff for the site was determined using the rational method, as detailed above. The entire site will have three (3) drainage basins and zero (0) off -site basins. The basins have been revised to direct runoff to the existing detention pond and to limit site disturbance to the extent practicable. p1LVLl,U IL Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufman & Robinson, Inc. July 8, 2013 Page 5 Basin A: This basin is located in the northwest/central portion of the site. Basin A includes the existing building, sidewalks, parking, access roadway, future parking and landscaping. Runoff from this basin will be conveyed to the existing detention pond (Pond A) via curb & gutter, concrete pan, sheet flow and a proposed grass swale. Basin B: This basin is located along the northern property line of the site. Basin B includes a concrete pan and landscape area and drains to the existing detention pond (Pond A). Runoff will be conveyed via the concrete pan. This basin has not been revised with this Amendment. Basin C: This basin is located in the southern/eastern part of the site and contains more than half of the site area. Basin C includes the proposed building addition, future building, existing Pond A, landscaping and undisturbed area. This basin has been designed to drain to the detention pond via sheet flow and grass swale. The following table shows the expected runoff from the proposed basins, based on the current site layout. Table 1: Runoff Summary Basin ID Area ac. 10 cfs 1nu cfs A 0.71 2.98 7.07 B 0.08 0.09 0.24 C 0.95 1.51 3.85 C. Detention: Detention for this site will be provided in existing Pond A, which is located on the eastern portion of the site. The detention pond was designed to have a maximum release rate of 0.35 cfs. The pond has been redesigned to provide 0.35 ac-ft of storage (including WQCV). The release rate is based on 0.2 cfs/acre, as allowed in the Dry Creek Basin. The release from the pond will be controlled by an existing outlet structure and have a single -stage release (100-year). The outlet structure is not being modified with this development. The volume of Pond A is based on the 2-hour, 100-year design storm. The existing invert of the pond is 4966.44 and the 100-year water surface elevation will be 4967.78, based on existing elevations. Furthermore, the detention pond will have approximately 1 foot of freeboard and an emergency overflow spillway. The pond will release into the existing Evergreen West pond, which has an existing high water elevation of 4962.5. The 100-year water surface elevation of the Evergreen West pond is 4965.2 and the maximum water surface elevation is 4966.0. Refer to "Detention Calculations" (Section C) for additional information. MiUbLILINE Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufinan & Robinson, Inc. July 8, 2013 Page 6 D. Open Channel Flow: Concrete pans (2') are proposed in the bottom of the existing detention pond. Furthermore, a temporary grass -lined swale with minimum 4:1 slopes is proposed south of the parking area to convey runoff to the existing detention pond. These conveyances will see relatively low to moderate flows and drain to existing and proposed storm drainage improvements. E. Inlets: There are no storm drainage inlets proposed with the improvements on this site. A future inlet structure will be installed with the development of the future building in the southern portion of the site. F. Storm Sewer: The proposed on -site storm sewer consists of an 18" RCP that will be utilized with the development of the future building in the southern portion of the site. The existing pond outlet pipe is a 12" ADS. The invert out of the pipe has a flared -end section and a riprap pad to control velocity as the storm water flows to the Evergreen West pond. IV. STORMWATER QUALITY AND SEDIMENT/EROSION CONTROL A. Stormwater Quality: The existing detention pond contains a stormwater quality component as part of the facility. The detention pond design and volume will include 0.029 ac-ft of water quality capture volume. The release from the outlet structure will be controlled by an existing water quality plate and orifice plate. A temporary grass -lined Swale is proposed in the middle portion of the site. This swale has been sized to accept the 100-year flow from Basin A. This swale has been designed to have 4:1 side slopes and should provide a level of water quality for runoff from the parking and drive areas that flow to Pond A. B. Sediment/Erosion Control: The site grading for the proposed project will occur during the initial phase of construction. Several sediment and erosion control measures will be incorporated into this initial phase of construction. The initial sediment and erosion control measures to be installed shall include silt fence along the southern property line, as well as vehicle tracking control to the south of the site entrance. Furthermore, additional measures for sediment and erosion control shall consist of providing straw wattles at low points in the curb & gutter as well as wattle dikes in the proposed grass - lined swale. Also, there is an area near the west property line designated for a concrete washout area. p1LVMIAL Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufman & Robinson, Inc. July 8, 2013 Page 7 Additionally, any area that has been disturbed by construction activities and left exposed for more than thirty (30) days, shall receive drilled seeding and straw mulch at 2 tons/acre, until permanent landscaping or ground cover has been provided. All stormwater quality and sediment/erosion control measures shall be regularly inspected and maintained during and after the completion of construction for the site. Furthermore, sufficient care shall be taken by the contractor with materials handling and storage. The proposed measures for sediment and erosion control shall be updated as necessary during construction, and as warranted by site conditions. V. CONCLUSIONS A. Impact of Improvement: The drainage design for the Kaufman & Robinson, Inc. Shop Addition, Evergreen Park Fourth Filing is in general accordance with the City of Fort Collins Storm Drainage Design Criteria and the Urban Drainage and Flood Control District Criteria Manual. The drainage design also utilizes recommendations from the City of Fort Collins Drainage Basin Master Plan. Furthermore, site disturbance is minimized to the extent practicable. The runoff from this site will be controlled by existing and proposed storm drainage facilities and improvements, including the detention pond. The drainage design for this project should not negatively impact adjacent properties or the existing storm drainage system. B. State Compliance with Applicable Criteria: The Kaufman & Robinson, Inc. Shop Addition, Evergreen Park Fourth Filing drainage design is in general compliance with the City of Fort Collins criteria. The Urban Drainage and Flood Control District Criteria Manual has also been utilized in the completion of the drainage design for this site. p1LULLENE Consultants, Inc. Amendment No. 1 to the Final Drainage and Erosion Control Report Evergreen Park Fourth Filing - Kaufman & Robinson, Inc. Julv 8.2013 VI.REFERENCES 1. City of Fort Collins Storm Drainage Design Criteria and Construction Standards, revised January 1997. 2. Urban Drainage and Flood Control District, Drainage Criteria Manual Volumes 1 and 2, prepared by Wright- McLaughlin Engineers, dated March 1969 (updated June 2001), and the Volume 3 prepared by Wright -McLaughlin Engineers, dated September 1992 and revised July 1999. 3. Evergreen Park Drainage Plan & Report, prepared by VTN Colorado, dated June 11, 1973. 4. Master Storm Drainage and Detention Plan for Evergreen Park, prepared by Cornell Consulting Company, no date. 5. Final Drainage and Erosion Control Report for Lots I & 2, Block 5, Replat (No. 1) of Evergreen Park, prepared by Shear Engineering Corporation, dated January 1999. 6. Final Drainage and Erosion Control Report - Evergreen Park Fourth Filing, prepared by Ridgeline Consultants, Inc., dated March 23, 2010. Consultants, Inc. \ X Z J (5) �I / //N W uj a< 0, LLI/ / ow 0 of �� / oz of c L // 0-0 c c N 0 LLI U)ZW � I �oo Q I ;� �, I m II �ma Of �w °r° U? a II I II �JLZ.—.—._. II5 ob 0� a s 00 Z Z V. a • : III I �i ' � �� W m v oV a. I I r/ I ° ° V Q Of ° I I 0 o II N w w0 �` p w 0_ Z N w/ OU °dI ° OJj Of Cif D N ° a O ICI o 0) � I CLInw� I \ \�((D0_�� W �HZ 00;� J�WO_ 0 Z H 0' Z Z D — U U 1\3Z I H w Z / W N U/� OU / \ rl < b Q / \ W � (/) H � I D c �^ \ /? a ? Z \ Hvdroloizic Calculations RIDGELINE Consultants, Inc. Runoff Coeffecients Sub -Basins A-1 Project: Kaufman & Robinson, Inc. Shop Addit T� ^�T T�T� Location: Blue Spruce Drive/Red Cedar Circle 13 j`�L V L ■ 11 r L Fort Collins, Colorado i a Project Number: 0114 Consttltnnts, Inc Date: May-13 All calculations presented are based upon the criteria set forth in the City of Fort Collins Storm Drainaee Design Criteria and Construction Standards May 1984 (Revised March 1991 & January 19971 Basin A (ac) (sq.ft) (%) Design Point Surface Improvement Area Area C I Comments I % of site area Lawns, Sandy soil (flat <2%) 0.09 3905.9 0.20 0.00 12.6% Curb & gutter and walks 0.11 4674.0 0.95 96.00 15.1 % Paved Parking & Drives 0.30 12869.2 0.95 100.00 41.6% Roofs 0.22 9500.0 0.95 90.00 30.7% Avg. 0.86 83.71 100.0% Total Area 0.71 0.86 83.71 Basin B (ac) (sq.ft) (%) Design Point Surface Improvement Area Area C I Comments 2 % of site area Lawns, Sandy soil (flat <2%) 0.07 3119.6 0.20 0.00 88.1% Curb & gutter and walks 0.01 421.8 0.95 96.00 11.9% Paved Parking & Drives 0.00 0.0 0.95 100.00 0.0% Roofs 0.00 0.0 0.95 90.00 0.0% Avg. 0.29 11.43 100.0% Total Area F 0.08 0.29 11.43 Basin C (ac) (sq.ft) (°/u) Design Point Surface Improvement Area Area C I Comments 3 % of site area Lawns, Sandy soil (flat <2%) 0.63 27461.0 0.20 0.00 66.0% Curb & gutter and walks 0.00 0.0 0.95 96.00 0.0% Paved Parking & Drives 0.00 0.0 0.95 100.00 0.0% Roofs 0.32 14126.9 0.95 90.00 34.0% Avg. 0.45 30.57 100.0% Total Area 0.95 0.45 30.57 Overall Site (ac) (sq.ft) (%) Design Point Surface Improvement Area Area C I Comments 3 % of site area Lawns, Sandy soil (flat <2%) 0.79 34486.5 0.20 0.00 45.3% Curb & gutter and walks 0.12 5095.8 0.95 96.00 6.7% Paved Parking & Drives 0.30 12869.2 0.95 100.00 16.9% Roofs 0.54 23626.9 0.95 90.00 31.1% Avg. 0.61 51.30 100.0% Total Area 1.75 0.61 51.30 PH2O114 runoff coeff.xlslSutrBasins 5/26/2013 M a V1 E O vi .E r O� N F- CC Z E = r U W 2 U F W U o00 z W " z F- O U W N N M o z°z y G= o > Q [J] c N N O W � � d F z � oM T U� N OHO R U o 0 0 U M W N 7 o 0 0 cn Q CC Q N r O a cn � N M O Q CO U 07 a'm I _O 0 00 b A-2 m "I" �101 0 9 0 >> o JI N � yl 0 a A-3 Project: Kaufman & Robinson, Inc. Shop Addition Location: Blue Spruce Drive/Red Cedar Circle Fort Collins, Colorado Project Number: 0114 Date: May-13 Rational Method Direct Runoff- 10-YR A-4 p1"vL1Jlr JLANL Consultants, Inc. Rational Method: Q = CfCIA Q: Q: Runoff in cfs (peak) C: C: Runoff Coefficient Cr: Cr: Frequency Adjustment Factor I: I: Rainfall Intensity (in/hr) for design event A: A: Basin Area (acres) 10-YEAR Design Point Basin ID Area C CfC t' I Q10 1 A 0.71 0.86 0.86 5.0 4.90 2.98 4.2 cfs/acre 2 B 0.08 0.29 0.29 9.1 3.92 0.09 1.1 cfs/acre 3 C 0.95 0.45 0.45 12.2 3.48 1.51 1.6 cfs/acre F:\Ridgeline\Projects\0I 14\Phase 2\Ph20114 rationalAs 5/26/2013 Project: Kaufman & Robinson, Inc. Shop Addition Location: Blue Spruce Drive/Red Cedar Circle Fort Collins, Colorado Project Number: 0114 Date: May-13 pl�v Rational Method: Q = CfCIA Q: Q: Runoff in cfs (peak) C: C: Runoff Coefficient Cr. Cr. Frequency Adjustment Factor 1: I: Rainfall Intensity (in/hr) for design event A: A: Basin Area (acres) 100-YEAR Rational Method Direct Runoff- 100-YR A-5 NT El IP l..IA —Consultants, Inc. Design Point Basin ID Area C CfC t� I Q100 A 0.71 0.86 1.00 5.0 9.95 7.07 10.0 cfs/acre 2 B 0.08 0.29 0.36 8.5 8.20 0.24 3.0 cfs/acre 3 C 0.95 0.45 0.57 12.2 7.10 3.85 4.0 cfs/acre 3 ALL 1.75 0.61 0.76 12.2 7.10 9.46 5.4 cfs/acre F:\Ridgeline\Projects\0114\Phase 2\Ph20114 rationalAs 5/26/2013 Hydraulic Calculations p1LviLINE Consultants, Inc. B-1 Worksheet for Shop Addition Grass -Lined Swale - 100-YR Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 2.00 % Left Side Slope 4.00 ft/ft (H:V) Right Side Slope 4.00 ft/ft (H:V) Discharge 7.07 ft3/s Results Normal Depth 0.71 ft Flow Area 2.04 ft' Wetted Perimeter 5.90 ft Top Width 5.72 ft Critical Depth 0.72 ft Critical Slope 0.01919 ft/ft Velocity 3.46 fUs Velocity Head 0.19 ft Specific Energy 0.90 ft Froude Number 1.02 Flow Type Supercritical LGVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.71 ft Critical Depth 0.72 ft Channel Slope 2.00 % Critical Slope 0.01919 ft/ft Ridgeline Consultants, Inc. Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.066.00] 5/2612013 5:47:13 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755.1666 Page 1 of 1 Cross Section for Shop Addition Grass -Lined Swale 100-YR Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 2.00 % Normal Depth 0.71 ft Left Side Slope 4.00 ft/ft (H:V) Right Side Slope 4.00 ft/ft (H:V) Discharge 7.07 ft3/s Cross Section Image 7N H. 1 B-2 Ridgeline Consultants, Inc. Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.066.00] 5126/2013 5:49:37 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1.203.755.1666 Page 1 of 1 Lebo Scenario: Base CB-1 Cu 1 0-1 Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8i (SELECTseries 3) KRi Addition 2013-03.stsw Center [08.11,03.77] 5/26/2013 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 c 0 w Profile Report Engineering Profile - Profile - 1 (KRi Addition 2013-03.stsw) 70.00 65.00 - -0+50 0+00 CB-1 Rim: 69.00 ft Invert: 67.35 ft CO-1: 90.0 ft @ 0.005 ft/ft Circle - 18.0 in PVC Station (ft) 0+50 B-4 0-1 Rim: 68.75 ft Invert: 66.90 ft 1+00 Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8i (SELECTsenes 3) KRi Addition 2013-03.stsw Center (08, 11.03.77] 5/26/2013 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1-203-755-1666 C 0 = n o o o VI - O x B-5 Detention Calculations RJILDGELINE Consultants, Inc. 100 Year Volume 1*11-lykel[C] Project Kaufman & Robinson, Inc. Shop Addition Location: Blue Spruce Drive/Red Cedar Circle Fort Collins, Colorado Project Num 0114 Date: May-13 'C'value 0.61 'C'' 125 0.7625 Area I.75 acres Release Rate F 0.35 DETENTION POND SIZING (100-Year) p1LVL1, JAL Consultants, Inc. Required detention ft acre-ft. TIME TIME NTENS Q 100 Runoff Release Rec aired Rec aired cum 100 year Volume Cum total Detention Detention (mans) (sees) (in/hr) (cfs) (ft"3) (tl^3) (ft^3) (ac-ft) 0 0 0 0.00 0 0.0 0.0 0.0000 5 300 9,950 13.28 3983.109 105.0 3878.1 0.0890 10 600 7.720 10.30 6180.825 210.0 5970.8 0.1371 15 900 6.520 8.70 7830.113 315.0 7515.1 0.1725 20 1200 5.600 7.47 8967 420.0 8547.0 0.1962 25 1500 4.980 6.65 9967.781 525.0 9442.8 0.2168 30 1800 4.520 6.03 10856.48 630.0 10226.5 0.2348 35 2100 4.080 5.44 11432.93 735.0 10697.9 0.2456 40 2400 3.740 4.99 11977.35 940.0 11137.4 0.2557 45 2700 3.460 4.62 12465.73 945.0 11520.7 0.2645 50 3000 3.230 4.31 12930.09 1050.0 11880.1 0.2727 55 3300 3.030 4.04 13342.42 1155.0 12187.41 0.2798 60 3600 2.860 3.82 13738.73 1260.0 12478.71 0.2865 65 3900 2.720 3.63 14155.05 1365.0 12790.1 0.2936 70 4200 2.590 3.46 14515.33 1470.0 13045.3 02995 75 4500 2.480 3.31 14891.63 1575.0 13316.6 0.3057 80 4800 2.380 3.18 15243.9 1680.0 13563.9 0.3114 85 5100 2.290 3.06 15584.17 1785.0 13799.2 0.3168 90 5400 2.210 2.95 15924A3 1890.0 14034.4 0.3222 95 5700 2.130 2.84 16200.65 1995.0 14205.6. 0.3261 100 6000 2.060 175 1649188 2100.0 14392.9 0.3304 105 6300 2.000 2.67 16813.13 2205.0 14608.1 03354 110 6600 1.940 2.59 17085.34 2310.0 14775.3 0.3392 115 6900 1.890 2.52 17401.58 2415.0 14986.6 0.3440 120 7200 1.840 2.46 17677.8 2520.0 15157.8 0.3480 125 7500 1.790 2.39 17913,98 2625.0 15289.0 0.3510 130 7800 1.750 2.34 1821422 2730.0 15484.2 0.3555 135 8100 1.710 2.28 18482.43 2835.0 15647.4 0.3592 140 8400 1.670 2,23 18718.61 2940.0 15778.6 0.3622 145 8700 L630 118 18922.77 3045.0 1587T8 0.3645 150 9000 1.600 2.14 19215 3150.0 16065.0 0.3688 155 9300 1.570 2.09 19483.21 3255.0 16228.2 0.3725 160 9600 1.540 2.05 19727.4 3360.0 16367.4 0.3757 165 9900 1.510 2.01 19947.57 3465.0 16482.6 0.3784 170 10200 1.480 1.97 20143.73 3570.0 16573.7 0.3805 175 10500 1.450 1.93 20315.86 3675.0 16640.9 0.3820 180 10800 1.420 1.89 20463.98 3780.0 16694.0 0.3830 185 11100 1.400 1.87 20736.19 3885.0 16851.2 0.3969 190 11400 1.380 1,94 20992.39 3990.0 17002.4 0.3903 195 11700 1.360 1.81 2123158 4095.0 17137.6 0.3934 200 12000 1.340 1.79 21456.75 4200.0 17256.8 0.3962 205 12300 1.320 1.76 21664.91 4305.0 17359.9 0.3985 210 12600 1.300 1.73 21857.06 4410.0 17447.1 0.4005 215 12900 1.280 1.71 22033.2 4515.0 17518.2 0.4022 220 13200 1.260 1.68 2219333 4620.0 17573.3 0.4034 225 13500 1.240 1.65 2233T44 4725.0 17612.4 0A043 230 13800 1220 1.63 22465.54 4830.0 17635.5 0.4049 235 14100 L210 1.61 22765.77 4935.0 17830.8 0.4093 240 14400 1.2()0 1.60 230581 5040.0 18018.01 0.4136 100-Year Volume C-1 Page 1 Erosion Control Calculations p 1MATIT IN E Consultants, Inc. C-2 STAGE -STORAGE FOR IRREGULAR GEOMETRY Project: Kaufman & Robinson, Inc. Shop Addition Basin ID: Revised Detention Pond A 5/28/2013 Design Information (Input): irsa r;ot : :;ita grad r:g r,ar, a:,tei water surface elevations and measured contour areas in ascending order. Water Surface Elevation ft Eq-elev. Contour Area square feet Volume above Datum acre-ft 4966.44 01 0.000 49665011 250 0.000 4966 86]1 6.8001 0.029 4967.00 15,100 0.064 4967.50 16,025 0.243 4967,78 16,700 0.348 4968.00 17,275 0.434 4968.79l 17,775 0.752 r� IWQSEL 1 100-yr WSEL ITop of Pond KRI pond volume 2013-03-01.xls, Irregular 5/2612013, 6:56 PM in Project: Kaufman & Robinson, Inc. Shop Addition Location: Blue Spruce Drive/Red Cedar Circle T r Fort Collins, Colorado PT j `Vi�l�� r Completed by: twc IVIiiD L Project Number: 0114 Consultants, Inc. Date: May-13 Standard Form A All calculations presented are based upon the criteria set forth in the CCU of FortCollins Storm Drainage Design Criteria and Construction Standards May 1984 (Revised March 1991 & January 1997) RAINFALL PERFORMANCE STANDARD EVALUATION Area 1 (to Detention Pond A) Developed Subbasin Erodibility Zone Asb (ac) Lsb (11) Ssb (%) Aix L; Aix Si Lb (11) Sb (%) PS M A Moderate 0.71 255.0 0.76 181.18 0.54 B Moderate 0.08 240.0 0.69 19.51 0.06 C Moderate 0.95 390.0 0.50 372.34 0.48 TOTAL 1.75 573.03 1.07 328.10 0.61 73.3 Asb = Subbasin Area L,b= Subbasin Flow Path Length Ssb= Subbasin Slope Lb= Average Flow Path Length (Sum A; x L;/Sum A;) Sb = Average Slope (Sum A; x S;/Sum A;) PS is taken from Table 5.1 (through interpolation) PH20114 ec calcs.xlskRainfall Performance 5/26/2013 D-2 Project: Kaufman & Robinson, Inc. Shop Addition pT�iFT T�T� Location: Blue Spruce Drive/Red Cedar Circle Fort Collins, Colorado 1161L V LULL I L Completed by: twc C011su[t(tnts, inC. Project Number: 0114 Date: May-13 Standard Form B All calculations presented are based upon the criteria set forth in the City of Fort Collins Storm Drainage Design Criteria and Construction Standards May 1984 (Revised March 1991 & January 1997) EFFECTIVENESS CALCULATIONS Treatment -Factor Bare Soil (roughened condition) Gravel Filter, Sand Bag Silt Fence Barrier Asphalt/Concrete Grass A- 1 it. Mf.oAnn DnnA AI P-Factor Comments 1.00 0.90 1.00 0.80 Wattle Filter 1.00 0.50 0.01 1.00 0.06 1.00 A,y Erosion Control Methods Developed Subbasin (ac) A 0.71 Bare Soil (Roughened Condition) Asphalt/Concrete 0.22 0.08 Grass 0.09 Gravel Filter, Sand Bag x Silt Fence x Net C-Factor 0.32 Net P-Factor 0.92 Eff [(I -C X P) X 100] = 70.6 B 0.08 Bare Soil (Roughened Condition) Asphalt/Concrete 0 0 Grass 0 Gravel Filter, Sand Bag Net C-Factor 0.00 Net P-Factor 0.40 Eff [(I -C X P) X 1001 _ 100.0 C 0.95 Bare Soil (Roughened Condition) Asphalt/Concrete 0.15 0 Grass 0.6 Gravel Filter, Sand Bag x Silt Fence x Net C-Factor 0.20 Net P-Factor 1.24 Eff [(1 -C X P) X 1001= 75.1 Total Area 1.75 Required PS 73.30% Total Effectiveness 74.42% IThe Proposed Plan is OK PH20114 ec calcs.xlslEC Effectiveness 5/26/2013 7 • D-3 Project: Kaufman & Robinson, Inc. Shop Addition Location: Blue Spruce Drive/Red Cedar Circle Fort Collins, Colorado Completed by: twc Project Number: 0114 Date: May-13 EROSION CONTROL OPINION OF COST Consultants, Inc. Item Description Work Item Units Quantity Unit Price Total EROSION CONTROL ECl Silt Fence If 460 $ 4.00 $ 1,840.00 EC2 Wattle Filter ea 6 $ 350.00 $ 2,100.00 EC3 Wattle Dike ea 2 $ 250.00 $ 500.00 EC4 Vehicle Tracking Control ea 1 $ 650.00 $ 650.00 EC5 Concrete Washout Area ea 1 $ 500.00 $ 500.00 IV, `xt : ". s;�Tota1= $ 5,590.00 CITY RESEEDING COST FOR SITE AREA RS1 Reseed/Mulch (all disturbed area) acre 1.3 $ 800.00 $ 1,040.00 1,040.00 REQUIRED DEPOSIT FOR EROSION CONTROL Erosion Control $ with*Facfor:M5) $ 5,590.00 8,385.00 PH2O114 cc calcs.xls\Estimate 5/26/2013