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HomeMy WebLinkAboutMULBERRY LEMAY CROSSING, PHASE 3 (KFC/TACO BELL) - PDP & FDP - 36-96F & G - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPRWEC �_ — /Yl location/mot/S HIGHLINE 4n&7 rd / Computations for2t5,1D(JYearReturn Period Design Storm_ Year Motor Storm /dy Year ENGINEERING & SURVEYING Computations by _ /Z/z It Dole 7 O/ RUNOFF COMPUTATIONS- Joe No. 1 7 3 " Checked by Date Rational Method PAGE of Design Area' A C FLOW IN STREET FLOW IN PIPE TRAVEL TIME j Point Designation (acres) AaC EAC Tc I Oc.f.s. (min) (initir.) EACaI Lengin Slope Vel, AT REMARKS EAC Ocf.s. Capacity 7AC70c (feet) (%) (tpsj (min.) 2- YF ►A R, 1 K- 0,37 67 0,61 Z K-Z. 0,0 00 o,to 1 K- 0;11 .81 0,Uj 0,13 ,57 0110 3 K I.0 i - Lts 1 K-) 0,11 ,89 0A Z K-Z- 0,73 ,89 otZC 3 K 110 S,o Z,85 It9 5r o Z t85 o t u 1961 S,O Z,b5 Z, 5 5, o 5,0 U-7 110 Deb, S-n loll y,3 S,o 9-95 z , 0 e,R,9l 5,p 9.95 g, 8 STANDARD FORM SF-8 TIME OF CONCENTRATION SUBDIVISION K F C Q muLIF,zi� LF_ on aY CACULATED BY 1A DATE Wo I t{ = L16ov- tc= tt+tt SUB -BASIN DATA INITIAL/OVERLAND TIME (t •) TRAVEL TIME tt tc (URBANIZED CHECK BASINS) FINAL tc REMARKS DESIG: (�) C5 (2) AREA Ac (3) LENGTH Ft (4) SLOPE % (5) ti Min (6) LENGTH Ft (7) SLOPE % (8) VEL. FPS (9) tt Min (10) LENGTH Ft (II) tc=(L/IBl+10 Min (12) Min (13) o•S-7 0,1 33o 0,1(v 117 3.Z — S, f , Z o,bl OX3 Zo 1 7.0 )15 G5 `I,tp 9,4 510 TC, Y►)IN w� •�v wow...• .. ��--_____ _ _ _ - - ..--- ..�---•- • �- •--•.••• vng • crnn MlAmumL WRC ENGINEERING, INC. Vold A City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes -60 minutes) Figure 3-1b Duration (minutes) 2-year Intensity (WAO 10-year Intensity fin&O 100-year Intensity (Irvhr) 31.00 1.27 2.16 4.42 32.00 1.24 2.12 4.33 33.00 1.22 2.08 4.24 34.00 1.19 2.04 4.16 35.00 1.17 2.00 4.08 36.00 1.15 1.96 4.01 37.00 1.13 1.93 3.93 38.00 1.11 1.89 3.87 39.00 1.09 1.86 3.80 40.00 1.07 1.83 3.74 41.00 1.05 1.80 3.68 42.00 1.04 1.77 3.62 43.00 1.02 1.74 3.56 44.00 1.01 1.72 3.51 45.00 0.99 1.59 3.46 46.00 0.96 1.67 3.41 47.00 0.96 1.84 3.36 48.00 0.95 1.62 3.31 49.00 0.94 1.60 3.27 50.00 0.92 1.58 3.23 51.00 0.91 1.56 3.18 52.00 0.90 1.54 3.14 53.00 0.89 1.52 3.10 54.00 0.88 1.50 3.07 55.00 0.87 1.48 3.03 56.00 0.88 1.47 2.99 57.00 0.85 1.45 2.96 58.00 0.64 1.43 2.92 59.00 0.83 1.42 1 2.89 60.00 0.82 1 1.40 2.88 Ann :On AA-ww-a m^ City of Fort Collin Rainfall Inteneltypuratlon-Frequency Table for using the Rational Method (5 minutes - 30 minutes) Figure 3-1a Duration 2-year 10-year 100•year (mirx,tes) Intensity Intensity Intensity inlhr 5•� 2.85 4.87 9.95 8.00 2.67 4.58 9.31 7.00 2.52 4.31 8.80 8.00 2.40 4.10 8338 9.00 2.30 3.93 8.03 10.00 221 3.78 7.72 11.00 2.13 3.63 7.42 12.00 2.05 3.50 7.16 13.00 1.98 3.39 6.92 14.00 1.92 3.29 8.71 15.00 1.57 3.19 6.52 16.00 1.61 3.08 6.30 17.00 1.75 2.99 6.10 18.00 1.70 2.90 5.92 19.00 1.65 2.82 5.75 20.00 1.61 2.74 5.60 21.00 1.50 2.67 5.46 22.00 1.53 2.61 5.32 23.00 1.49 2.55 5.20 24.00 1.48 2.49 5.09 25.00 1.43 2.44 4.98 1.40 2.39 4.87 27.00 1.37 LE28.00 2.34 4.78 28.00 1.34 2.29 4.69 29.00 1.32 2.25 4.60 30.00 1.30 2.21 4.52 BO'd .ion t wn No Text DRAINAGE CRITERIA MANUAL RUNOFF 50 30 1- 20 Z w U w 10 2 w a O 5 N w En U 2 C w Q 1 I I I la �o r T tiW O �f J_ y J I T a C7 j` I I J y4T mT yC I c 3` Q O y W 4T f OW V W • QT I 1 I I I I I I I 1 1 I I I I I I I I 1.1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I v I vIII I I I I I I .2 .3 .5 I 1 1 �5 2 3 5 10 20 VELOCITY IN FEET PER SECOND Figure 3-3 ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA. " MOST FREQUENTLY OCCURRING "UNDEVELOPED" LAND SURFACES IN THE DENVER REGION. REFERENCE:: "Urban Hydrology For Small Watersheds" Technical Release No. 55, USDA, SCS Jan. 1975. 5-1-64 URBAN DRAINAGE & FLOOD CONTROL DISTRICT DRAINAGE CRITERIA MANUAL 1 OF A RUNOFF TABLE 3-1 (42) RECOMMENDED RUNOFF COEFFICIENTS AND PERCENT IMPERVIOUS LAND USE OR PERCENT FREQUENCY SURFACE CHARACTERISTICS IMPERVIOUS 2 5 10 100 Business: Commercial Areas 95 .87 .87 .88 .89 Neighborhood Areas 70 .60 .65 _ .70 .80 Residential: Single -Family * .40 .45 .50 .60 Multi -Unit (detached) 50 .45 .50 .60, .70 Multi -Unit (attached) 70 .60 .66 .70 .80 1/2 Acre Lot or Larger * .30 JS .40 .60 Apartments 70 .65 .70 .70, .80 Industrial: Light Areas 80 .71 .72 .76 .82 Heavy Acres 90 .80 .80 .85 .90 . Parks, Cemetaries: 7 .10 .10 .35 .60 Playgrounds • 13 .15 .25 .35 .65 Schools: 50 .45 .SO :60 - .70 - Railroad Yard Areas - 40 - .40 .45 .50 - .60 Undeveloped Areas: Historic Flow Analysis- 2 (See "Lawns") Greenbelts. Agricultural Offsite Flow Analysis (when land 45 .4; .47 .55 .65 use not defined) Streets: Paved 100 .87 .88 ..90 .93 Gravel 13 .15 .-.25 .35 .65 Drive and Walks: 96 .87 .87 ,Bg ' Roofs: 90 .80 .85 .90 .89 .90 Lawns. Sandy Soil 0 .00 .01. .OS .20 Lawns, Clayey Soil 0 :05 .10 .20 .40 NOTE: These Rational Formula coefficients may not be valid for large basins. *See Figure 2-1 for percent impervious. 5-1-84 Sin insurance �.m at (900) _.. CE PROGRAM TE MAP NOT PRINTED) UNITY -PANEL NUMBER 080102 0004 C MAP REVISED: MARCH 18, 1996 r_eryency Management Agen j 0 Portions of this exhibit were taken from Larimer County Pane 179 of 278, #080101 01790, March 18, 1996. i I APPENDIX Waste building materials shall be collected by a reputable waste management company and transported to a legal waste disposal facility. Site inspections shall be performed weekly to assure onsite collection. No dedicated concrete or asphalt batch plants are proposed on the site. D. Final Stabilization and Long Term Stormwater Management After infrastructure construction is complete, runoff will be directed via onsite parking and drives to a detention pond and continued conveyance via storm sewer to Irondale Gulch. After completion of the buildings, pavement, and landscape by the builder, the owner shall maintain the property in good functioning order. The stormwater quality is then classified as urban runoff. E. Other Controls Offsite soil tracking is limited by the restriction of construction traffic to a single access and by a periodic street sweeping. Waste disposal shall be by means of a local waste management company. Implementation of the controls shall be by the erosion control plan which is part of the contract documents. F. Inspection and Maintenance Maintenance procedures are outlined in the notes contained on the overlot grading and erosion control details. A log record noting all inspections and mitigation efforts shall be kept with the construction manager. 173kfc.drg C. Best Management Practices (BMP) for Stormwater Pollution Prevention a) Erosion and Sediment Control Structural practices : Overlot grading operations present the greatest opportunity for pollution of state waters. Due to the nature of the site, disturbed areas shall be contained by a perimeter silt fence which shall remain in place until non-structural ways and means are established. Upon completion of the overlot grading, surface runoff velocities shall be attenuated by slope reduction and erosion bales as check dams and sediment trapsas needed. The grading improvements generally direct runoff to a central point of site release thereby permitting point source methods of pollution abatement management practices. Surface areas remain denuded during utility construction, but the structural elements remain in place. Maintenance procedures shall be recorded by the developer's construction manager in a log book. 2. Non-structural Practices : upon completion of the street hardscape, all exposed portions of the site having a slope of 4:1 or greater shall be seeded mulched. Silt and sediment deposits shall be removed and spread evenly in open areas and mulched as necessary. Upon establishment of surface vegetation, structural erosion control measures shall then be removed whereby non-structural methodology shall be practiced. An approximate schedule for implementation of the measures is shown on the Erosion Control Details. b) Materials Handling and Spill Prevention Potential pollutant material brought onsite would be fuel for earth moving and trenching equipment. Berm shall be provided at the fueling site as a containment measure. There will be no permanent bulk fuel storage on this site. The Fire Protection District is equipped for spill cleanup. Any contaminated materials shall be properly disposed of. Other potential pollutant material includes concrete wash water. This shall be done in areas designed by the developer's construction manager and protected from runoff and, after hydration, buried in designated non -construction zones. Building materials are expensive and shall be protected by storage outside of runoff areas. This shall be performed by the materials owner to protect the inherent value and no additional measures will be taken. 173kfc.drg 6 Building Schedule 1. Foundation Excavation 2. Foundation Backfill 3. Above grade building construction 4. Domestic wet utility connection 5. Dry utility installation 6. Driveway / patio/ sidewalk installation 7. Precise lot grading 8. Reseeding and / or sodding per Landscape Plan c) The total area of the site is approximately 1.1 acres. The area of the site expected to undergo grading activities is approximately 1.1 acres not including public roadways. d) Runoff coefficients and soils data are identified in this Final Drainage Study. e) Little vegetation exists on this site consisting mainly of recently overlot graded bare ground covering approximately 95 % of the site. f) Potential pollution sources include equipment refueling and maintenance, grading operations, and concrete wash water. g) No significant non-stormwater components of runoff are anticipated. h) Receiving waters are initially minor tributaries and storm sewer outfalls to the Poudre River. B. Site Maps The maps, taken from the "Construction Plans for KFC//A&W at Mulberry and Lemay", include: Drainage Study & plan, Grading Plan, Erosion Control Plan. 173kfc.drg 5 EROSION CONTROL The purpose of this plan is to provide additional information and requirements for Erosion Control associated with Construction Activity". A. Site Description a) The proposed construction activity is development of A fast food restaurant with all relevant amenities including, but not limited to, streets, utilities, and drainage improvements. b) The anticipated sequence of construction is as follows : 1. Installation of perimeter erosion control measures 2. Site Clearing & Demolition 3. Overlot grading 4. Installation of temporary onsite erosion control measures and temporary traps 5. Utility Construction 6. Drainage improvements construction including sediment traps at inlets and erosion protection at outfall locations 7. Street, Parking, and Building Fine Grading (See Building Schedule) 8. Street curb, gutter, walk, and building 9. Street Paving 10. Seeding and mulching of open space areas 11. Removal of erosion control appurtenances after site is stabilized. 173kfc.drg 4 IV. DRAINAGE FACILITY DESIGN In accordance with the Final Drainage Report for Mulberry and Lemay Crossings, runoff for both the design and major storm events of the site will be conveyed overland within paved parking and drives north toward the 48-inch outfall tributary to the detention pond in sub - basin P2. A high point will be constructed to split and convey onsite developed runoff overland to both entrances onto the north shared drive as depicted on the approved drainage study. V. CONCLUSION The drainage facilities for a portion of lot 6 of Mulberry and Lemay Crossings Filing No. 2 were designed in accordance with the Final Drainage Report for Mulberry and Lemay Crossings and the City of Fort Collins Storm Drainage Criteria. Developed runoff will be conveyed overland to the approved outfall Tributary to the detention pond as shown on the approved report. Prepared by or under the direct supervision of Russell B. Hall, PE & PLS Colorado Registration No. 26715 REFERENCES 1. " Final Drainage Analysis Mulberry and Lemay Crossings", prepared by Colorado Land Consultants, Inc., revised January 25, 2000. 173kfc.drg 3 I. INTRODUCTION Mulberry and Lemay Crossings Filing No. 2 is a 15.5 acres office/retail development. The KFC/Taco Bell Pad Site is a portion of Lot 6 Mulberry and Lemay Crossings Filing No. 2 consisting of 1.09 acres. A Final Drainage Report for Mulberry and Lemay Crossings has been approved as prepared by Colorado Land Consultants, Inc., (CLC), revised July 25, 2000. Having all storm sewer, detention and other infrastructure currently under construction, this report identifies that the proposed improvements for the KFC/Taco Bell has been designed in accordance with the Final Drainage Report for Mulberry and Lemay Crossings. II. GENERAL LOCATION AND DESCRIPTION The project site consists of 1.09 acres is located at the northeast corner of East Magnolia Street and South Lemay Avenue. The proposed restaurant will face west toward East Magnolia Street. The interior shared private drive and parking of the shopping center are located north of the project site. The site is located within the southwest quarter of Section 7, Township 7 North, Range 68 West of the 6th Principal Meridian, City of Fort Collins, Larimer County, State of Colorado. Presently, Mulberry and Lemay Crossings Filing No. 2, including the KFC / Taco Bell site, is currently under construction. It is anticipated that all infrastructure will be in place prior to construction of the KFC / Taco Bell site. No plans currently exist to develop the remainder of lot 6, and it is anticipated that the developer of this area will be required to conform to the approved plans and designs for the overall shopping center prepared by CLC. M. DRAINAGE BASIN AND SUB -BASINS The site lies within the Poudre River drainage basin. The approved Final Drainage Report for Mulberry and Lemay Crossings depicts the subject site located within Sub -basins B-8 and B-9. 48-inch storm sewer with catch basins are depicted on the approved drainage plan approximately 110 feet north of the site being tributary to a detention pond located in sub - basin P2. The storm sewer is designed to intercept developed runoff from the minor storm event and a portion of the major storm event and continue conveyance to the detention pond in sub -basin P2. Runoff from the major storm event not intercepted by the storm sewer outfall will continue conveyance to the detention pond overland via paved parking and drives. The detention Pond in Sub -basin P2 is designed to attenuate developed runoff for both the 10 and 100 year storm event, and continue conveyance to the Poudre River. 173kfc.drg 2 DRAINAGE STUDY FOR KFC / TACO BELL RESTAURANT A PORTION OF LOT 6 OF MULBERRY AND LEMAY CROSSINGS FLING NO. 2 CITY OF FORT COLLINS, LARIMER COUNTY, COLORADO July 18, 2001 PREPARED FOR: ARCHITEKTON 398 SOUTH MILL AVENUE, SUITE 301 TEMPE, AZ 85281 (480)894-4637 PREPARED BY: HIGHLINE ENGINEERING AND SURVEYING COMPANY 9101 EAST KENYON AVENUE, SUITE 2500 DENVER, COLORADO 80237 (303) 889-0044/(303) 889-0012 fax DWG NO. 173