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HomeMy WebLinkAboutDrainage Reports - 07/14/1995` PROPERTY OF Fi=ia PAW '�•�i FORT COLLINS U" ag SHEAR ENGINEERING CGRPEMEN .11 Final Drainage and Erosion Control Report for SPRING HOLLOW MINOR SUBDIVISION (Spring Hollow Condominiums) Ft. Collins, Colorado PREPARED FOR: William Coulson 221 Mathews Street, # 20 Fort Collins, Colorado 80524 PREPARED BY: SHEAR ENGINEERING CORPORATION Project No: 1450-01-94 Date: May, 1995 4836 S. College, Suite 12 Fort Collins, CO 80525 (303)226-5334 n U 0 May 1, 1995 Project No. 1450-01-94 Basil Hamdan City of Fort Collins Storm Water Utility P.O. Box 580 Ft. Collins, Colorado 80522 Re: Spring Hollow Minor Subdivision; Fort Collins, Colorado Dear Basil, Enclosed, please find the Final Drainage and Erosion Control Report for Spring Hollow Minor Subdivision (Spring Hollow Condominiums). The hydrology data and the hydraulic analysis presented in this report complies with the requirements of the City of Fort Collins Storm Drainage Criteria Manual; dated March, 1984, and the Erosion Control Reference Manual. If you have Shear Engineering Corporation BWS / mb cc: William Coulson ease call me or Mark Oberschmidt at 226-5334. 4836 S. College, Suite 12 Fort Collins, CO 80525 (303)226-5334 Page 1 Spring Hollow Condominiums Final Drainage and Erosion Control Report L GENERAL LOCATION AND DESCRIPTION: A. Location 1. Spring Hollow Minor Subdivision is located in the Northwest Quarter of Section 24, 17N, R69W of the 6th P.M., City of Fort Collins (Larimer County), Colorado. 2. More specifically, Spring Hollow Minor Subdivision is located between Remington and Mathews Streets and south of the Spring Creek Country Day School. 3. The site is bounded on the north by the Spring Creek Country Day School, on the east by Mathews Street, on the south by the Sherwood Ditch (Arthur Ditch Company) and Dartmouth Avenue, and on the west by Remington Street. B. Description of Property 1. Spring Hollow Minor Subdivision will consist of the development and construction of 28 condominium units (Spring Hollow Condominiums) and the site infrastructure to service them. • 2. The total area of the development is 1.934 acres. 3. Sewer, water and other utilities are available to service the site from both Remington and Mathews Streets. 4. Access to the site will be provided from both Remington and Mathews Streets. 5. The site is currently vacant with wild dryland grasses and other vegetation. II. DRAINAGE BASINS AND SUB -BASINS: A. Major Basin Description 1. Spring Creek Minor Subdivision is located in the Spring Creek Basin as delineated on the City of Fort Collins Storm Water Basin Map. a. The Basin fee rate for this basin is $ 2,175.00 per gross acre according to the development fee section of the City of Fort Collins Development Manual. b. Our understanding is that the above mentioned fees may be reduced with the provision for detention. 2. All stormwater runoff from the site eventually reaches Spring Creek. The primary • release point into Spring Creek from this site is a series of 2' Combination Type 13 inlets located on Spring Park Drive. The inlets are connected by a 15" RCP storm sewer. Page 2 Spring Hollow Condominiums Final Drainage and Erosion Control Report I. DRAINAGE BASINS AND SUB -BASINS: A. Major Basin Description (continued) 3. The existing 100 year flood Computed Water Surface Elevation (CWSEL) at cross section #64 is estimated in the Spring Creek Master Drainage Way Plan at 4,978.61 feet above sea level. Refer to Table 8 - Flood Elevation Data - Developed Conditions, of the Spring Creek Master Drainageway Plan. The flood way elevation at cross section # 64 is 4979.60 feet above sea level. Refer to Table 11 - Floodway Data, of the Spring Creek Master Drainageway Plan. Cross section 64 is located approximately halfway between the intersections of Spring Park Drive and Remington Street and Spring Park Drive and Mathews Street. These values have been confirmed with FEMA flood plain information. 4. Spring Hollow Minor Subdivision is not located within the 100 year flood plain U. DRAINAGE BASINS AND SUB -BASINS: • B. Sub -Basin Description 1. Historically, stormwater runoff from the entire site flows north overland to the Spring Creek Country Day School. 2. Historically, the site consists of the one basin (Basin Ih) which contributes storm water to the school and eventually to Spring Creek via the series of existing inlets located on Spring Park Drive. 3. Development of the site will redirect the majority of the stormwater runoff from the site to Remington and Mathews Streets. The proposed grading will create a high point at the western entry drive. This will create two (2) sub -basins (I and 111) which will contribute stormwater to the respective streets. Sub -basins I and 11 consist of 0.96 and 1.47 acres respectively. a. A small portion of the site (minor basin Io = 0.03 acres) contributes stormwater runoff to the Spring Creek Country Day School. The amount of this runoff is negligible due to the size of the minor basin and the fact that the entire minor basin will be covered with grass.. 4. The developed sub -basins include the 1/2 street R.O.W. of Remington and Mathews Streets in accordance with City of Fort Collins Standards. The developed sub -basins also include a portion of the Arthur Ditch located along the south property line. • Page 3 Spring Hollow Condominiums Final Drainage and Erosion Control Report M. DRAINAGE AND EROSION CONTROL DESIGN CRITERIA: A. Regulations: 1. All storm drainage design calculations and considerations are in conformance with the City of Fort Collins Storm Drainage Criteria Manual. 2. All erosion control design is in conformance with the City of Fort Collins Erosion Control Reference Manual. IM DRAINAGE AND EROSION CONTROL DESIGN CRITERIA: B. Development Criteria Reference and Constraints 1. Grading constraints exist on all four sides of the site. These include: a. Remington Street is constructed to its final width along the west side of the site. This limits the grading that can be done along the west property line. • b. Mathews Street is constructed to its final width along the east side of the site. This limits the grading that can be done along the east property line. c. The Spring Creek Country Day School adjoins the site to the north. This limits the grading that can be done along the north property line. d. The Arthur Ditch adjoins the site along the south property line. This limits the grading that can be done along the south property line. 2. Existing site grading, the proposed improvements to the site and the adjoining property, have been considered in the final grading and drainage design for Spring Creek Condominiums. C. Hydrological Criteria 1. The Rational Method for determining peak flows to various critical design points, has been used for the evaluation of the 2 and 100 year storm events. D. Hydraulic Criteria 1. The Mannings formula has been utilized for determining capacities for storm sewers and open channels. Mannings "n" values, as suggested by the criteria manual, were utilized. • e Page 4 Spring Hollow Condominiums Final Drainage and Erosion Control Report IV. DRAINAGE FACILITY DESIGN: A. General Drainage Concept 1. Generally, all storm runoff will be conveyed from Spring Creek Minor Subdivision undetained to Mathews Street and Remington Street. It is our understanding from reviewing the Spring Creek Master Drainageway Plan that the recommendations made for improvements, if implemented, throughout the drainageway would achieve a developed basin with a 100 year recurrence level of protection. 2. Remington and Mathews Streets will be the primary means of conveyance of stormwater to Spring Creek. a. Stormwater runoff from the site and upstream areas will be intercepted by a 2' Type 13 combination inlet located on Spring Park Drive. b. Stormwater is then conveyed to Spring Creek in a 15" RCP. c. A grouted rip rap apron already exists at the outfall to Spring Creek. d. Flows which exceed downstream infrastructure capacity, will overflow the • Spring Park Drive curb into Spring Creek. e. The existing 100 year flood Computed Water Surface Elevation (CWSEL) at cross section #64 is estimated in the Spring Creek Master Drainage Way Plan at 4,978.61 feet above sea level. 3. Stormwater runoff from within the site will be conveyed to Remington Street and Mathews Street by a combination of : a. Grassed swales b. Gutter flow in the driveways. 0 Page 5 Spring Hollow Condominiums Final Drainage and Erosion Control Report IV. DRAINAGE FACILITY DESIGN: B. Specific Details 1. Detention will not be provided on this tract. A variance has been requested from the City of Fort Collins Storm water standards. Refer to Section VII of this report. 2. The existing 2' Type 13 combination inlet located on the south side of Spring Park Drive is in sump condition. a. The historic 100 year peak flow to the inlet from the contributing area upstream is approximately 164.0 cfs. Refer to exhibit 'A' for the contributing upstream area. Refer to pages 2 - 4 in the drainage calculations located in Appendix I. b. The developed 100 year peak flow to the inlet from the contributing area upstream is approximately 167.9 cfs. i. The developed condition assumes the development of Spring Hollow Minor Subdivision as shown on the attached Utility Plans for Spring Hollow Condominiums. • c. Due to the proximity of the inlets on Spring Park Drive to Spring Creek, any water that is not intercepted by the inlets, will overflow directly into Spring Creek. d. The existing 100 year flood Computed Water Surface Elevation (CWSEL) at cross section #64 is estimated in the Spring Creek Master Drainage Way Plan at 4,978.61 feet above sea level. e. The flow line elevation at existing 2' Type 13 combination inlet located on the south side of Spring Park Drive is 4,977.86 feet above sea level. 3. The developed 100-year peak flow to the northwest corner of the site at Remington Street (Concentration Point A) from sub basin I is 7.28 cfs. a. The slope of Remington Street at concentration point A is 2.40 percent. b. The allowable half street capacity of Remington street for the minor storm at concentration point A is 19.92 cfs. Refer to exhibit B. c. The allowable half street capacity of Remington street for the major storm at concentration point A is 171.66 cfs. Refer to exhibit B. 0 • Page 6 Spring Hollow Condominiums Final Drainage and Erosion Control Report IV. DRAINAGE FACILITY DESIGN: B. Specific Details (Continued) 4. The developed 100-year peak flow to the northeast corner of the site at Mathews Street (Concentration Point B; flow in Mathews Street) from sub basin U is 10.11 cfs. a. The slope of Mathews Street at concentration point B is 1.32 percent. b. The allowable half street capacity of Mathews Street for the minor storm at concentration point A is 38.2 cfs. Refer to exhibit C. c. The allowable half street capacity of Mathews Street for the major storm at concentration point A is 210.63 cfs. Refer to exhibit C. 5. The developed 100-year peak flow to the northeast corner of the site at Mathews Street (Concentration Point D; flows in the drive) from sub basin Ild is 5.71 cfs. a. The slope of the driveway at concentration point B is 0.5 percent. • b. A 6" high inflow curb has been provided along the north side of the driveway. c. The driveway has a cross slope of 2.0%. d. The capacity of driveway based on a flow depth of 0.50' at the curb is 9.31 cfs. Refer to page 12 in the calculations. 6. The developed 100-year peak flow to the northwest corner of the the parking lot near garage no. 6 (Concentration Point C; flows in the drive) from sub basin IIc is 5.48 cfs. a. A four (4') foot curb cut is provided in the corner of the parking lot. b. A four (4') foot concrete valley pan is provided to convey the stormwater to Remington Street. c. The slope of the four (4') foot concrete valley pan is 0.78%. d. Mannings 'n' value for concrete is 0.016. d. The capacity of the four (4') foot concrete valley pan is 8.91 cfs. Refer to page 9a in the drainage calculations located in Appendix I. 40 • Page 7 Spring Hollow Condominiums Final Drainage and Erosion Control Report IV. DRAINAGE FACILITY DESIGN: B. Specific Details (Continued) 7. The developed 100 year peak flow from minor basin Io (Area = 0.03 acres) onto the Spring Creek Country Day School is 0.07 cfs based on the following assumptions. a. Time of Concentration is 5.0 minutes. This is the shortest allowable time of concentration. b. The 100 year rainfall intensity (I100) for a Tc of 5.0 minutes is 9.30 inches per hour. c. A'C' factor of 0.20 was used for the grass. Therefore, the C100 factor is 0.25 or 1.25 x 0.20. d. Q 100 = (0.25) x (9.30) x (0.03) = 0.07 cfs e. This is significantly less than the historic peak flow which would be calculated • using the entire platted area of 1.934 acres. 8. A grassed swale has been provided along the west side of garage No. 5. An easement has been provided on the final plat. a. The peak 100 year flow for the swale is 0.16 cfs. One hundred and thirty three percent (133%) of Q100 is 0.21 cfs. Refer to page 13 and 13a in the drainage calculations located in Appendix L b. The triangular grassed Swale has the following cross section Depth = 0.5'. ii. Side slopes are 4:1. iii. Mannings'n' is 0.032. iv. The slope of the channel varies from 4.0 to 10.0%. c. The capacity of the channel using a slope of 4.0% and Mannings equation is 3.61 cfs. 0 • Page 8 Spring Hollow Condominiums Final Drainage and Erosion Control Report V. EROSION CONTROL FACILITY DESIGN: A. General Erosion Control Concept 1. Erosion protection will be provided in accordance with City of Fort Collins Standards and with generally accepted erosion control practices. B. Specific Details 1. Silt fence will be provided along the northern property line and along other downstream property lines as needed. 2. Hay bale barriers will be provided in the grassed swale along the west side of garage No. 5. 3. A gravel inlet filter will be provided at the curb cut for the four (4') foot wide concrete valley channel located at the northwest corner of the site (Concentration point C). A gravel curb filter will also be provided at the northeast corner of the site (concentration point B) to intercept any erosion that may leave the site via the driveway. • VI. EROSION CONTROL SECURM DEPOSIT: A. An erosion control security deposit is required in accordance with City of Fort Collins policy (Chapter 7, Section C : SECURITY; page 7.23 of the City of Fort Collins Development Manual). In no instance shall the amount of the security be less than $1000.00. 1. According to current City of Fort Collins policy, the erosion control security deposit is figured based on the larger amount of 1.5 times the estimated cost of installing the approved erosion control measures or 1.5 times the cost to re -vegetate the anticipated area to be disturbed by construction activity. i The cost to install the proposed erosion control measures is approximately $2,022.50. Refer to the cost estimate attached in Appendix I. 1.5 times to install the erosion control measures is $ 3,033.75 H. Based on current data provided by the City of Fort Collins Storm Water Utility, and based on an actual anticipated net affected area which will be disturbed by construction activity (approximately 2.0 acres), we estimate that the cost to re - vegetate the disturbed area will be $1,300 ($650.00 per acre x 2.0 acres). 1.5 times the cost to re -vegetate the disturbed area is $1,950.00. The $650.00 per acre for re -seeding sites of less than 10 acres was quoted to us by the City of Fort Collins Storm Water Utility staff. 2. The erosion control security deposit amount required for this project will be • $3,033.75. See the Erosion Control Security Deposit Requirements document located in Appendix IV. 3. The erosion control security deposit is reimbursable. • Page 9 Spring Hollow Condominiums Final Drainage and Erosion Control Report VII. VARIANCE FROM CITY STANDARDS A. Variance from City of Fort Collins requirements 1. With this report, the developer is formally requesting a variance from the standard requirement of stormwater detention. The primary reason for this is that the recommendations made for improvements in the Spring Creek Master Drainageway Plan, would achieve a developed basin with a 100 year recurrence level of protection. Therefore individual site detention would not be required. VIH. CONCLUSIONS: A. Compliance with Standards 1. This report complies with the requirements of the City of Fort Collins Storm Drainage Criteria Manual, Erosion Control Reference Manual, dated 1984 and the Spring Creek Master Drainage Plan. B. Variance from City of Fort Collins requirements • 1. See Section VII for the formally requested variance from City of Fort Collins Standards. C. Drainage and Erosion Control Concepts 1. The grading plan will allow for the effective conveyance of storm water runoff from the site to existing storm drainage conveyance facilities, and ultimately to the Spring Creek. 2. Erosion protection will allow for the protection of downstream storm drainage facilities. IX. REFERENCES: 1. City of Fort Collins Storm Drainage Criteria Manual 2. City of Fort Collins Erosion Control Reference Manual 3. Spring Creek Master Drainage Way Plan; Prepared by Engineering Professionals, Inc.; Dated March, 1988 0 • APPENDIX I Storm Drainage Calculations Erosion Control Calculations 0 PLOW SUMMARY FOR SPRING HOLLOW CONDOMINIUMS DESIGN SUB AREA C2 C10 C100 Tc Tc I2 I10 I100 Q2 Q10 Q100 DESIGN 2,10 100 POINT BASIN ac. min. min iph iph iph cfe cfe cfe . rrr rr rr ru.rrr• rrrrr rrrrr rrrrr ..... .rrrr rrrr rrr+r rrrrr urrr rrrr. .rrrr rrrrr rrrr. INLET A HISTORIC 33.55 0.66 0.66 0.E3 16.00 16.00 2.08 3.65 5.89 46.06 80.82 164.02 INLET A DEVELOPED 33.55 0.66 0.68 0.85 16.00 16.00 2.08 3.65 5.89 42.45 83.27 167.97 A Ia & Ic 0.93 0.69 0.69 0.86 5.00 5.00 3.29 5.64 9.10 2.11 3.62 7.28 SP B IIb,IId,IIe 1.47 0.64 0.64 0.79 6.50 6.00 3.22 5.52 9.71 3.03 5.19 10.11 SP C Ic 0.20 0.64 0.64 0.79 5.00 5.00 3.29 5.64 8.71 1.59 2.22 5.48 PAN D IId 0.64 0.63 0.63 0.78 6.50 6.00 3.22 5.52 8.71 1.70 2.92 5.71 GP E Ile 0.41 0.49 0.49 0.61 5.00 5.00 3.29 5.64 9.10 0.66 1.13 2.28 SCCDS Io . 0.03 0.20 0.20 0.25 5.00 5.00 2.29 5.64 9.10 0.02 0.03 0.07 NA ABBREVIATIONS I/P = INLET AND PIPE SF = STREET PLOW SW = SWALE PAN = PAN I = INLET GF = GUTTER PLOW SCCDS= SPRING CREEK COUNTRY DAY SCHOOL • SHEAR ENGINEERING CORPORATION PAGE: 1 PROTECT: SPRING HOLLOW MINOR SUBDIVISION PILE: SPCRKC. WK1 PROTECT NO.: 1450-01-94 BY: MBO DATE 04/26/95 SUBBASIN SUMMARY SUB AREA ASPHALT ROOF LAWN COMPOSITE C100= BASIN ACRES CONCRETE C. C = 0.95 0.95 0.25 r rr rrrr rr+rrrrrr+rrrrrrr rrrrrrrtt+rrrrrrrrrrrrrr +++rr♦++ Ia 0.23 0.12 0.02 0.09 0.68 0.85 Ic 0.70 0.25 0.19 0.26 0.69 0.86 Io 0.03 0.00 0.00 0.03 0.25 0.31 I 0.96 0.37 0.21 0.38 0.67 0.64 IIb 0.22 0.22 0.00 0.00 0.95 1.00 IId 0.84 0.22 0.23 0.39 0.63 0.78 IIe 0.41 0.07 0.07 0.27 0.49 0.61 II 1.47 0.51 0.30 0.66 0.64 0.79 • TOTAL 2.43 0.88 0.51 1.04 TOTAL AREA INCLUDES 1/2 STREET ROW FROM MATHEWS AND REMINGTON STREETS AND SOME OFPSITE AREA LOCATED WITHIN THE DITCH BASEMENT THIS BREAKDOWN IS FOR ON SITE PORTIONS OF SUBBASINS ONLY SUB ARRA ASPHALT ROOF LAWN COMPOSITE C100= BASIN ACRES CONCRETE C. C = 0.95 0.95 0.25 Ia 0.11 0.00 0.02 0.09 0.36 0.47 Ic 0.70 0.25 0.19 0.26 0.69 0.86 Io 0.03 0.00 0.00 0.03 0.25 0.31 I 0.84 0.25 0.21 0.38 0.63 0.79 IId 0.84 0.22 0.23 0.39 0.63 0.78 IIe 0.41 O.OI 0.07 0.27 0.49 0.61 11 1.25 0.29 0.30 0.66 0.58 0.73 TOTAL 2.09 0.56 0.60 1.32 171 SHEAR ENGINEERING CORPORATION PAGE: A PROTECT: SPRING HOLLOW MINOR SUBDIVISION PILE: SPCRKC. WK1 PROTECT NO.: 1450-01-94 BY: MHO DATE 04/28/9S DESIGN CONTRIBUTING AREA COMPOSITE COMPOSITE POINT MINOR C C100 BASINS FACTOR A Ia,Ic 0.93 0.69 0.86 C Ic 0.70 0.69 0.86 B IIb,IId,IIe 1.47 0.64 0.79 D IId 0.84 0.63 0.78 E IIe 0.41 0.49 0.61 • • I t_�^^ Il u.tY7. i I�3i iJ • Ifs6-0-"¢ t�z113093Zu)t (►-)S- is/I 1 �IL`ltyx 2zo, = 1,9b1 i00 s� = 33.55 ac See Exl b,1 A ry SkU�T<r • �1STtv.c Pw9 A4ov)rY C A 5pr�o�r7Cru\ C,00�?r.JfO�,.JSc�,00� �-5o'I,SM. 0.S 1,3g V Nu\t,Q.\dp� 5v?C Cj r,4.i 1 7 rav S,�, .: o�S u ) O,ZU 2� shy 0.1,b G = 0, 6% 4Z neJe\0�e� Cwo = I:LS lG� = 0.`65 33 1e�per�J\O�:.�V�S� J L • • SHEAR ENGINEERING CORPORATION PAGE 3 HISTORIC PLOW TO CONCENTRATION POINT INLET A FROM HISTORIC BASIN I PROJECT: SPRING HOLLOW CONDOMINIUMS DATE 02/27/95 FILE: SPCRKRUN PROJ. N0.1450-01-94 NOTES: SEE EXHIBIT A BY MHO AREA (A)= 33.550 ACRES RUNOFF COEF. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.66 0.66 0.82 SEE CALCULATIONS ON PAGE 2 TIME OF CONCENTRATION (TO OVERLAND TRAVEL TIME (Ti) NOT APPLICABLE LENGTH = 0 FRET SLOPE = 0.00 t 2 YEAR 10 YEAR 100 YEAR C = 0.00 0.00 0.00 Ti (min)= 0.00 0.00 0.00 TRAVEL TIME (Tt)=L/(60+V) FLOW TYPE L (it) = 620 S (t) = 0.50 GUTTER L (ft) = 930 S (t) = 2.80 GUTTER L (it) = S80 S (t) = 1.60 GUTTER L (ft) _. 5 (t) . L (ft) S (t) . L (ft) S (t) _. . L (ft) S (t) _. . NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc=T,TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 15.94 15.94 15.94 USE Tc = 16 16 16 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 2.08 3.65 5.89 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfs) 2 YEAR 10 YEAR 100 YEAR Q = 46.06 80.82 164.02 CONCLUDR:COMPARR WITH DEVELOPED FLOWS V (fps) = 1.50 Tt(min)= 6.89 V (fps) = 3.20 Tt(min)= 4.84 V (fps) = 2.30 Tt(min)= 4.20 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 TOTAL TRAVEL TIME (min) = 15.94 . SHEAR ENGINEERING CORPORATION PAGE 4 DEVELOPED PLOW TO CONCENTRATION POIN INLET A FROM DEVELOPED BASIN PROTECT: SPRING HOLLOW CONDOMINIUMS DATE 02/27/95 PILE: SPCRKRUN PRAT. NO.1450-01-94 NOTES: SEE EXHIBIT A BY MEO AREA (A)= 33.550 ACRES " RUNOFF CORP. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.68 0.68 0.85 SEE CALCULATIONS ON PAGE 2 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) NOT APPLICABLE LENGTH = 0 FEET SLOPS = 0.00 t 2 YEAR 10 YEAR 100 YEAR C = 0.00 0.00 0.00 Ti (min)= 0.00 0.00 0.00 TRAVEL TIME (Tt) =L/(60*V) PLOW TYPE L (ft) 620 S (t) = 0.50 GUTTER V (fps) = 1.50 Tt(min)= 6.89 • L (ft) = 930 S (t) = 2.80 GUTTER V (fps) = 3.20 Tt(min)= 4.84 L (ft) = 580 S (t) = 2.60 GUTTER V (fps) = 2.30 Tt(min)= 4.20 L (ft) _. S (t) _. V (fps) _. Tt(min)= 0.00 L (ft) _. S M _, V (fps) _. Tt(min)= 0.00 L (ft) _. S (t) _, V (fps) _. Tt(min)= 0.00 L (ft) _. S (t) _. V (fps) _. Tt(min)= 0.00 NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) = 15.94 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 15.94 15.94 15.94 USE Tc = 16 16 16 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 2.08 3.65 5.89 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfs) 2 YEAR 10 YEAR 100 YEAR Q = 47.45 83.27 167.97 HISTORIC Q = 46.06 80.82 164.02 PERCENT INCREASE= 3.02% 3.03% 2.41% • CONCLUDE:THE INCREASE IS NEGLIBLE AND THE PROXIMITY OF THE INLET TO SPRING CREEK ALLOWS FOR ALMOST IMMEDIATE OVER PLOW INTO SPRING CREEK SHOULD THE INLET CAPACITY BE EXCEEDED. Ll • 0 SHEAR ENGINEERING CORPORATION PAGE 5 PLOW TO CONCENTRATION POINT A FROM SUB BASIN(S) Ia & I. PROJECT: SPRING HOLLOW CONDOMINIUMS DATE 03/09/95 FILE: SPCRKRUN PRAT. NO.1450-01-94 NOTES: BY MHO AREA (A)= 0.930 ACRES RUNOFF CORP. (C) C = 2 YEAR 10 YEAR 100 YBAR 0.69 0.69 0.86 SEE CALCULATIONS ON PAGE 2 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) NOT APPLICABLE LENGTH = 0 PEST SLOPE = 0.00 k 2 YEAR 10 YEAR 100 YEAR C = 0.00 o.uo 0.00 Ti (min)= 0.00 0.00 0.00 TRAVEL TIME (It) =L/(60�V) FLOW TYPE L (ft) - 210 S (t) = 2.00 GRASSED SWALE L (ft) = 131 S (k) = 1.00 GUTTER L (ft) = 58 S (t) = 4.40 GUTTER L (ft) = 32 S (t) = 0.60 GUTTER L (ft) S (t) =a L (ft) _. S (t) L (ft) _. S (t) _. NOTE: ALL VELOCITIES TAKEN FROM PIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 3.28 3.28 3.28 USE Tc = 5 5 5 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 3.29 5.64 9.10 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfn) 2 YEAR 10 YEAR 100 YEAR Q = 2-.11 3.62 7.28 V (fps) = 2.10 Tt(min)- 1.69 V (fp0) = 2.00 Tt(min)- 1.09 V (fps) = 4.20 Tt(min)= 0.23 V (fps) = 1.80 Tt(min)= 0.30 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)- 0.00 TOTAL TRAVEL TIME (min) = 3.28 CONCLUDE:CHECK 1/2 STREET CAPACITY OF REMINGTON STREET SEE EXHIBIT ON PAGE 6 4;s U.§A F 114 A' RQ,it/e�\N5 (�O+V S I �:� a 2Y,3�` 0,b6 IafAtro ui = iA,-a.U�i pZ. 9zC\�)C.3C) = 3,z4 (a tnajo� = 1b,S0 A4=�2oko,5}+ + Jr � zZ++ + 4,S'+,mot + G 4� gz+l,i6t - 2b.g3 %U.S > �Zrrvwo�= 4'O-1� = O,Ih`6S Iz� 0t39ol � R.....�o� = 16.SI26,�d3 = D.bISO 7 itz13 : 0\1t51 12.'9.56 use, IWO. I) logy l l use.. I)OU S= OR -A ftl4t� 'l2 ��rcc Cti��s,_. � Ck (,zsQ tifa� stc WK STOP I�,yZ cf� 2,11 cEs fnA50a2 STdR6� 111,6E Gfs �,Z$s c�i EXWO�� 13 • 0 0 SHEAR ENGINEERING CORPORATION PAGE 9 FLOW TO CONCENTRATION POINT B FROM SUB BASIN(S) IIb,IId,II6 PROJECT: SPRING HOLLOW CONDOMINIUMS DATE 03/09/95 FILE: SPCRKRUN PRAT. NO.1450-01-94 NOTES: BY MEO ARRA (A)= 1.470 ACRES RUNOFF COEF. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.64 0.64 0.79 SEE CALCULATIONS ON PAGE 2 TIME OF CONCENTRATION (TO OVERLAND TRAVEL TIME (Ti) LENGTH = 35 FEET SLOPE = 14.00 % 2 YEAR 10 YEAR 100 YEAR C = 0.25 0.25 0.31 Ti (min)= 3.94 3.94 3.66 TRAVEL TIME (It) =L/(60-V) FLOW TYPE L (ft) = 40 S (i) = 2.26 GUTTER L (ft) = 30 S (1) = 2.00 GUTTER L (ft) = 165 S (4) = 0.50 GUTTER L (ft) S (i) _. . L (ft) =i S (4) _. . L (ft) S (%) _. . L (ft) _. S (4) P NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc=Ti1TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 6.45 6.45 6.17 USE Tc = 6.5 6.5 6 SEE NOTE ABOVE INTENSITY (1) (iph) 2 YEAR 10 YEAR 100 YEAR I = 3.22 5.52 8.71 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfs) 2 YEAR SO YEAR 100 YEAR Q = 3.03 5.19 10.11 CONCLUDE:CHECK 1/2 STREET CAPACITY OF MATHEWS STREET SEE EXHIBIT C ON PAGE 8 V (fps) = 3.00 Tt(min)= 0.22 V (fps) = 2.10 Tt(min)= 0.24 V (fps) = 1.50 Tt(min)= 2.06 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 TOTAL TRAVEL TIME (min) = 2.52 Pl 3 sT i 3 J I - ) ' AS 0.Q a aow,a s M"OR 51'WWN ,'cow oe pt,a e �E = 0163' rnll Son 3CoRrn h LLOu R3366 flow pear,,,` 1L = W 3' Cy O.S' pu¢i Cra.J,J NEGL1ALG:.IWOR60 i/U G LC IP,-��e it.1�) 0, Oo325f Mmoe ��prra. P= P 8.3$.si' H2='IZ(a�)C4s)t.04(4.5) 2.0 5� (F'01-s561j,,, P- A , I�sr • �4 = '�116,i�0,?�� = Z,,Z $F pmi,vU� = u25 + 2°a,,l t o,S :U747 r6,,- C. ',} ) c o,i7 $F Pam, gyp✓ 30,01 k 1 0,SZ t 7L R r„r+oi z 113T'J3o,o, = O,Z)-,Z. --7 lz 1k OA-00 R c*ojoi = VS.4c)132oj z 0,'14"l0 7 R113 = () 5%Z3S ) (O,i.,-,o / olb = 33z."�L USz 33ZA r � 6 \23.h1) (,%V�6)}',6iL c �i833,Zr� use- 0 0 • '� 5}'feR,� Carte=,<.�i�.� f`lS�IU:�. SiOail�ti 3`d,Z c,�t Q aF ©s L;y e CXit iR IT C. r�P;�+2 SiLa rr -e10 4-. In,11 cfs 171 • SMEAR ENGINEERING CORPORATION PAGE 9 FLOW TO CONCENTRATION POINT C FROM SUB BASIN(S) Ic PROTECT: SPRING HOLLOW CONDOMINIUMS DATE 04/28/95 FILE: SPCRKRUN PROD. NO.1450-01-94 NOTES: BY MEO AREA (A)= O.700 ACRES RUNOFF COEF. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.69 0.69 0.66 SEE CALCULATIONS ON PAGE I TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) NOT APPLICABLE LENGTH = 0 FEET SLOPE = 0.00 1 2 YEAR 10 YEAR 100 YEAR C = 0.00 0.00 0.00 Ti (min)= 0.00 0.00 0.00 TRAVEL TIME (TO=L/(60•V) PLOW TYPE L (ft) . 210 S (t) = 2.00 GRASSED $WALE L (Et) = 131 S (1) . 1.00 GUTTER L (ft) . 58 S (t) = 4.40 GUTTER L (ft) =i S (t) _. . L (ft) _) S (i) .7 . L (ft) S M _] . L (ft) .. S (4) =i ] NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc=Ti.TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 2.99 2.99 2.99 USE Tc . 5 5 5 SEE NOTE ABOVE INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I 3.29 5.64 9.10 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfe) 2 YEAR 10 YEAR 100 YEAR V (fps) = 2.10 Tt(min)= 1.67 V (fps) = 2.00 Tt(min)= 1.09 V (fps) = 4.20 Tt(min)= 0.23 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= 0.00 V (fps) _. Tt(min)= O.00 TOTAL TRAVEL TIME (min) = 2.99 Q = 1.59 2.72 5.48 CONCLUDE:INSTALL 4' CURB CUT AND 4' WIDE CONCRETE CHANNEL TO REMINGTON STREET W S 1.6 4 +0,� s 5•U S- 0,�51�, 12= Z%5 JZI3 O- 54 Z-7 �z.o)�o,4oi74 ,Uu1S6)ih 9,Ci � Cf-s �js G1ioo - S AO 0l� (rELF62�J F.`: hlyu • • SHEAR ENGINEERING CORPORATION PAGE 10 PLOW TO CONCENTRATION POINT FROM SUB BASIN(S) IId IJ PROTECT: SPRING HOLLOW CONDOMINIUMS DATE 03/09/95 PILE: SPCRKRUN PRAT. N0.1450-01-94 NOTES: BY MEO AREA (A)= 0.840 ACRES RUNOFF CORP. (C) 2 YEAR 10 YEAR 100 YEAR C = 0.63 0.63 0.78 SEE CALCULATIONS ON PAGE 1 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) LENGTH = 35 FEET SLOPE = 14.00 4 2 YEAR 10 YEAR 100 YEAR C = 0.25 0.25 0.31 Ti (min)= 3.94 3.94 3.65 TRAVEL TIME (Tt)=L/(60-V) PLOW TYPE L (ft) = 40 S (4) = 2.26 GUTTER L (ft) = 30 S (4) = 2.00 GUTTER L (ft) = 185 S (4) = 0.50 GUTTER L (ft) S (5) L (ft) S (i) =] L (ft) =. S (t) ? L (ft) =. S (t) NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 6.45 6.45 6.16 USE TC = 6.5 6.5 6 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I = 3.22 5.52 8.71 NOTE: INTENSITIES TA EN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfe) 2 YEAR 10 YEAR 100 YEAR Q = 1.70 2.92 5.71 V (fps) = 3.00 Tt(min)= 0.22 V (fps) = 2.10 Tt(min)= 0.24 V (fps) = 1.50 Tt(min)= 2.06 V (fps) =. Tt(min)= 0.00 V (fps) =. Tt(min)= o.oa V (fps) =. Tt(min)= 0.00 V (fps) =. Tt(min)= 0.00 TOTAL TRAVEL TIME (min) = 2.52 CONCLUDB:CHBCK CAPACITY OF DRIVEWAY ALONG THE NORTH PROPERTY LINE IF CAPACITY EXCEEDED COMPARE OVERFLOW WITH HISTORIC PLOW TO COUNTRY DAY SCHOOL SEE PAGE 11 1G to S-P V,Nmb NULL\ow ory op t�\:v�Jr*�5 N : O.UIb ZOx Sx = a,4o Us 0,s G\j.b vNtk),4- �d V a is 'I j �Zt = 0.3) 34 wt on' Sly I Giwu� I • .. �i CO's'C,�b u�'v I7Y1ut bJSt� L�-��:.�1J \5 (NO �i ?i I i E • SHEAR ENGINEERING CORPORATION PAGE 12 DEVELOPED PLOW TO SPRING CREEK COUNTRY DAY SCHOOL FROM SUB BASINS) IO PROTECT: SPRING HOLLOW CONDOMINIUMS PILE: SPCRKRUN NOTES: AREA (A)= 0.030 ACRES RUNOFF CORP. (C) C = 2 YEAR 10 YEAR 100 YEAR 0.20 0.20 0.25 GRASSED AREA BETWEEN BACK OF CURB AN TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) LENGTH = 10 FEET SLOPE = 5.00 % 2 YEAR 10 YEAR 100 YEAR C = 0.00 0.00 0.00 Ti (min)= 3.82 3.62 3.82 TRAVEL TIME (Tt)=L/(60=V) PLOW TYPE (ft) .7 S (5) _. ? L (ft) _. S 0) _? . L (ft) _. S (%) _? . L (ft) _. S (t) _. . L (ft) _. S (t) _. . L (ft) _. S (t) _. . L (ft) _. S (t) _. . NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 3.82 3.82 3.82 USE Tc = 5 5 5 INTENSITY (I) (iph) 2 YEAR 10 YEAR 100 YEAR I . 3.29 5.64 9.10 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfe) 2 YEAR 10 YEAR 100 YEAR Q = 0.02 0.03 0.07 DATE 04/25/95 PROD. NO.1450-01-94 BY HBO V (fp0) _. Tt(min)= 0.00 V (fp.) _. Tt(min)= 0.00 V (fp.) _. Tt(min)= 0.00 V (fp0) _? Tt(min)= 0.00 V (fp0) _. Tt(min)= 0.00 v (fpn) _. Tt(min). 0.00 V (fp0) _. Tt(min)= 0.00 TOTAL TRAVEL TIME (min) = 0.00 CONCLUDE:PBAK FLOW OFF THE SITE ONTO THE COUNTRY DAY SCHOOL IS SIGNIFICANTLY LESS THAN THE HISTORIC PEAK PLOW WHICH WOULD BE CONTRIBUTED BY THE ENTIRE SITE • SHEAR ENGINEERING CORPORATION PAGE 13 CHANNEL CAPACITY PROJECT NAME: SPRING HOLLOW MINOR SUED. DATE: 04/28/95 PROTECT NO. 14SO-01-94 BY : HBO SWALE DESCRIPTION:SWALE ON WEST SIDE OF GARAGE NO. 5 PILE: SPRCHAN CAPACITY OF TRIANGULAR OR TRAPEZOIDAL CHANNEL CHANNEL CONFIGURATION: TRIANGULAR DESIGN PLOW (cfs) 0.21 CHANNEL LINING: GRASS Da Db Dc Sc n W I (ft) (ft) (ft) (4) ----- (ft) ____ (ft) ____ ____ ____ 2.00 2.00 ____ ____ 0.50 4.00 0.032 0.00 0.10 0.25 = LEFT BANK SLOPE 0.25 = RIGHT BANK SLOPE • DEPTH WIDTH AREA PBRIM R 2/3 Sc 1/2 Q V (s.f.) (ft) (o.f.) (ft) (A/P) (cfo) (ft/sec) 0.50 4.00 1.00 4.12 0.39 0.20 3.61 3.61 0.40 3.20 0.64 3.30 0.34 0.20 1.99 3.11 0.30 2.40 0.36 2.47 0.28 0.20 0.92 2.57 0.20 1.60 0.16 1.65 0.21 0.20 0.31 1.96 0.10 0.80 0.04 0.82 0.13 0.20 0.05 1.24 0.00 0.00 0.00 0.00 0.00 0.20 0.00 0.00 CONTRIBUTING AREA TO SWALE 1900.00 SF 1600.00 SF GRASS 0.20 300.00 SF ROOF 0.95 Tc = 5.00 min C = 0.32 Iloo = 9.30 iph Cloo = 0.40 AREA = 0.04 ac Q100 = 0.16 cfo 1.33Q100= 0.21 cfs CONCLUDE:SWALE IS ADEQUATE • • • r_1 �I a N - r6 l d- 2: --4-7 • SHEAR ENGINEERING CORPORATION PAGE 14 DEVELOPED FLOW TO CONCENTRATION POINT E FROM SUB BASIN(S) II. PROTECT: SPRING HOLLOW CONDOMINIUMS DATE 06/12/95 FILE: SPCRKRUN PROT. NO.1450-01-94 NOTES: BY MEO AREA (A)= 0.410 ACRES RUNOFF COEF. (C) C = 2 YEAR 10 YEAR 100 YEAR 0.49 0.49 0.61 TIME OF CONCENTRATION (Tc) OVERLAND TRAVEL TIME (Ti) NA LENGTH =. FEET SLOPE _. 5 2 YEAR 10 YEAR 100 YEAR C = 0.00 0.00 0.00 Ti (min)= 0.00 0.00 0.00 TRAVEL TIME (Tt)=L/(60-V) FLOW TYPE L (ft) = 60 S (4) = 2.00 GRASSED SWALE V (fpe) = 2.16 Tt(min)= 0.46 • L (ft) = 10 S (4) - 4.40 GUTTER FLOW V (fpo) = 4.14 Tt(min)= 0.04 L (ft) = 110 S (4) = 0.50 GUTTER FLOW V (fpo) - 1.50 Tt(min)= 1.22 L (ft) = 20 S (4) - 5.00 GUTTER FLOW V (fpe) = 3.37 Tt(min)- 0.10 L (ft) _. S (4) _. V (fpo) _. Tt(min)= 0.00 L (ft) _. S (4) =J V (fpe) _. Tt(min)= 0.00 L (ft) _. S M =. V (fpe) _. Tt(min)= 0.00 NOTE: ALL VELOCITIES TAKEN FROM FIGURE 3-2 TOTAL TRAVEL TIME (min) 1.82 Tc =Ti+TOTAL TRAVEL TIME 2 YEAR 10 YEAR 100 YEAR Tc (min)= 1.82 1.82 1.82 USE Tc = 5 5 5 INTENSITY (I) (iph) 2 YEAR 10 YEAR - 100 YEAR I = 3.29 5.64 9.10 NOTE: INTENSITIES TAKEN FROM FIGURE 3-1 RUNOFF (Q= CIA) (cfo) 2 YEAR 10 YEAR 100 YEAR Q = 0.66� 1.13 2.28 CONCLUDE: ALLOW FLOWS TO CROSS DRIVEWAY AS THEY ARE PRETTY SMALL 0 114 0 III fr,,k -Mows -Lo I i v}el o,-� 5\»�, pr W Ai,,,�.. 51 46.nb c,�s $O:dZ c.� 16q.UZ cis - 7Je.�UU�7ed Q\U Q\\U i hSSU r e- L h t��2� 1 l`t} C oy�ru15 f o�\c1C asp C.-G_c..�'y-,c. S�Ycc�C f D✓ � �G✓\ C.. c.rv(1\ �e�c� u\� � +v5' 1 LOLJ \e-•s�� ice. +5 is c.,�1� �wot��mT•33_l._i1J 5s 1 ar (7r %e fSro,, 4+55-3 - lyl 5fl,}C_ o e-rn1 — apex U}e� O,1; - Q/A= 3,S 7 3,Sx3 1 lb,S XZ = ZI,Gc�s , rrw 1 M 1 fff-sy ILI 11 HI 1 1 1 .0, L _�.� ',i.-�:J� %'_.tea -Iv 1 '. (_s_I_�iJ i lam; i.-; �_`. . t_e i '-•i {I_.I I43 o ! lly i"w"I II- N Al1nII -io I- J1 I'! a II-in 4i 1 i Y KH""! H h I .I -mil I IVA l 10 i A. J��J �! I j �d ij Ell. ' d � I ip1' IOi r'�!�k � � f �. (' 4 I ! f. , � t ,. ('-� � I.�-.I �. 1 � ' � I I I ' i , I I I I ; I I { I ; ; ' ; ! 1n, i i If 1"'Y rj _19 Irl IF In 711- 7 -pj.f I 1,M I , " l - 1 -.. --! i to 1 UP lli W-1 IF -!: I` i 1 V r - I i 1 1 1 1 , do 1.9 1. 1 L 1 4w, JU Z, fill i l I 1 7- K A- 7 , 1 " 4 01 A T !- F", 11 MT will H Al , rli, 1 All 1 1 rill tl II,{i�lil, ,1 ' 1 11, i � ,i I le 1 J ,tt �I i, {{t) IVi,' t � !,bj' Qr 41 H ;6 04 rs 401- A.- 4 a In 0 Im 10, _m sr �jl LiLij i:]: ?+rfT It Q, r TVA W (7-5)-!1)t(-W,CI 4 c�- Sx 14 / I 3. , �u i' u n 1 GoNc�uc�c . 1hC NCYe4,S'Z_ e `tV c10.�e v\ CO,v u,J ��nJ„��, , il�so hh e.\ u,V . 1o`,�', 5vhc eley fog f�,s corv�r,h��n;ti/zc Is 7k53t I,0I(01� wo OUK)O, 15 Co,ds,ulerc� RAINFALL PERFORMANCE STANDARD EVALUATION • PROJECT: SVPNM6\AOLI-00 STANDARD FORM A COMPLETED BY: Ir\tu 511 sL c u(-t + ,::=R1r3DATE: Z r v. DEVELOPED ERODIBILITY Asb Lsb Ssb Lb Sb PS SUBBAgIN ZONE (ac) (ft) M (feet) M ($) Z p4� 3S0 2.4 ON Sti�'C , T1 j �, -i 31Z 2 — ---_-- I,SO 2 1tl 3U-L z,s i,lo 3•� 300 jV6 x - n\-I Gt a= i1. z <"qoo 3a�,2 ass; X l IOU z\Aj-,4Wl MARCH 1991 B-14 DESIGN CRITERIA • EFFECTIVENESS CALCULATIONS PROJECT: 5fIV.1 lc, t1CU(Sw rawol2 SUQb1JISromJ STANDARD FORM B COMPLETED BY: DATE: nk Erosion Control C-Factor P-Factor Method Value Value Comment 91b'1) G (-0VwA I) U 0 60 Ito OT Sd\J0`01 I,UO MAJOR PS SUB AREA BASIN ($) BASIN (Ac) CALCULATIONS 7),Z4 1 8,46 Y2UOP 0.0 7 K . PSPNhtt= O,zl see.. P ;e 1 0` .D::.. ,..: • . C`1os ON S,}e LOA w`N ` 0,13+c ONt� RO1IGZYNCC\ �Jf OVN\ � Ii00f �Se� C-JLt0,01 Y1,u.)+(0Z� x.01)+(0d3 xO,UI�]JDA9 h-1[,0?(•h) F I,o(.Z6+13]�o,46J x,� x,S rC 53,�� 1 �} Roof = a.ql D,zt t_,W IJ 0.15 0,01(.z$t,,s��llla� — 0.3Bg6 = n66 i MARCH 1991 B-15 DESIGN CRITERIA • CONSTRUCTION SEQUENCE PROJECT: SPRING HOLLOW MINOR SUBDIVISION STANDARD FORM C SEQUENCE FOR 19 ONLY COMPLETED BY:MEO/Shear Engineering Corp. 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. Year 194 95 Month A M J I A S O N D I F M A OVERLOTGRADING *** WIND EROSION CONTROL * Soil Roughening *** RAINFALL EROSION CONTROL STRUCTURAL: *_ Sediment Trap/Basin * Inlet Filters * Straw Barriers *** *** * Silt Fence Barriers *** *** 0 Asphah/Concrcte Paving *** *** VEGETATIVE: * Permanent Seed Planting *** *** *** * Sod Installation *** *** STRUCTURES: INSTALLED BY: OWNER MAINTAINED BY: OWNER VEGETATION/MULCHING CONTRACTOR: OWNER DATE PREPARED: 2/27/95 DATE SUBMITTED:2 2/ 7/95 APPROVED BY THE CITY OF FORT COLLINS ON: O mm000 o v4Uttnin in W WWcoW • o mmmm1 o1 o00 o ninln v wwW W WwW wW w w w W W W W W o aDmmmmmmmmmmm000 . . . . . . . o . . . . . . . . . vvvvvv�vvvrvinlnln M W W W W W W OD W W W W W W W W O rcDODOommmmmmmmmmmmmmmm . . . . . . . . . . . . O . . . . . . . . . V' V' V' V' V' V' V' V' V' V' V' V' v .1 V' 'Iry 0. 4 v N 00 W W Co OD W W W W 00 W OD W W W W OD W W 00 O oM V' In %D tD %D%D r r r r r r r r r r r r CO 00 N CO W 00 o O 4; vvd; 1; v vC Vv v 1; 4 v v v; 41; ;.4; dV [a H W W W W W W W W W W CO W W W CO W W W W W W CO W W W W O OD N M V'InUI U11D%D W%D%D%D r r r r r r r r r r W 00 CO p m 0 0000 WOD Wc Wv M 0000 0000 co M 0000000000 0000 00 Co 0000 OD M CO M M M 00 CO U o kDONMd'vUtinUlin%D %D %D %0 %D %D %DW %D10rrrrrr . . . . . . . . . . . . W . . . . . . . . . . . . . . . . V'vvOvvvvsr V'vvd' MMM z z WWWWWWWWWWWWWWMOD WWWWWWWWWW W MMMMM W MWMM H la O V m H N M M v d' V' V' U1 U1 U1 U1 U1 U1 U1 U1 U1 tD tD tD tD U1 tD r o r r�r�v�vv���v�rvvavvvvvvvv�vvv U W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W N OD W W W W W W W W W W W mmr-W CAo0H'iH NNNMMMMMvvvvv 1 O en . W W U) N M P mc4 4 ; 4 V' CO W CO W W W W W W CO W 00 OD W W W W W W W W 00 OD W W W • oa) ajtn H Co rI M y to ln%D to r r r co W co co Co co mmm00000 W . a � o-7O .r N N M M M M M M M M M M M M M M M M M M M v v v V' v E0 Cn OD 00 WOO W OD 00 WCOW W 00 00 OD 00 W WWWWWM00W W CO o COU1W O.-INMvvInInIn%oCD1D%D%Drrrr W W W mm H (/� 'V' •-1N NCIMMMMMMMMMMMMMMMMMMMMMM W W W W W W W W W W W W W W W W W W W W W W W W W W W U1 .-I.-I U1r W OO.iNNMMM V V V'd' VU1 U1 0 �DW Wrr M rI N N M N N M M M M M M M M M MM r4 4 4 44MM4 4 00 W CO W W W CO CO W W W 00 W W OD W CO 00 W W W W W W CO 00 O O 1D 1D f. N. W W m. O.iN N MM. M. 1� I1 V11 U1 U1 U1 U1111O W . ai M O CO N N N N N N N N N N N N N N N N N N N NN W W OD W CO W CO CO W W W W W W W W W W W W CO W W W W W W W CO W a U1 U1 U1 m1 MP., 10rrr W W W mmmmmm000000 a f] N mOO H H N N NNN N HCO H a CO CO CO 0000 M rWWWWWWWWWWWWWWWWWWWWWWWWW 0000 0000 OD 00 W O V'InOMU)l0 W W mOOO.i �i .-1.-INNNNMMMMMM H .y N W m OOo OOOO 01 rrWWWWWWWWOD0000COCOM0000000000CDOD000000 U1 W N W rl V'Inrr W mm00.-I.iNNNM1 M rM rrrrrrrrrrrWWWWWWWWWWWWWWW 0 W M O-.r r m O eA N M M v v In U1 U) U1%D W %D%D r r W%D%D W W W W W ro 0; ao W 0; ro Co C r Ct co C l CO Co Ct CO rrrrrrrrrrrrrrrrrrrrrrrrrr • U1 m0 i11 r: W W rr r 1D CD U) i i M M N Nm 1D i i C., 1! O O N N N N N N N N N N N N N N N N N N N• 4. -1 '1 '1 O O rrrrrrrrrrrrrrrrrrrrrrrrrr x SE-� o0000000000000000000000000 O U P 00000000000000000000000000 la7.W HNM VU11Dr W mOrINM V'U1�Dr W mOU1OU10U1O a • Table 86 C-Factors and P-Factors for Evaluating EFF Values. Treatment C-Factor P-Factor BARE SOIL Packed and smooth................................................................ 1.00 1.00 Freshly disked........................................................................ 1.00 0.90 Rough irregular surface........................................................... 1.00 0.90 SEDIMENT BASIN/TRAP................................................................. 1.00 0.50111 STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG ........................ 1.00 0.80 SILT FENCE BARRIER..................................................................... 1.00 0.50 ASPHALT/CONCRETE PAVEMENT ................................................... 0.01 1.00 ESTABLISHED DRY LAND (NATIVE) GRASS .......................... See Fig. 8-A 1.00 SODGRASS................................................................................. 0.01 1.00 TEMPORARY VEGETATION/COVER CROPS .................................... 0.45121 1.00 HYDRAULIC MULCH @ 2 TONS/ACRE........................................... 0.10f1 1.00 SOIL SEALANT....................................................................0.01-0.601a 1.00 EROSION CONTROL MATS/BLANKETS............................................ 0.10 1.00 •GRAVEL MULCH Mulch shall consist of gravel having a diameter of approximately 1 /4" to 1 1 /2' and applied at a rate of at least 135 tons/acre.............. 0.05 1.00 HAY OR STRAW DRY MULCH After planting grass seed, apply mulch at a rate of 2 tons/acre (minimum) and adequately anchor, tack or crimp material into the soil. Slope M 1 to 05.............................................................................0.06 1.00 6 to 10............................................................................. 0.06 1.00 11 to 15............................................................................. 0.07 1.00 16' to 20.............................................................................0.11 1.00 21 to 25............................................................................. 0.14 1.00 25 to 33.............................................................................0.17 1.00 > 33.......................................................................... 0.20 1.00 NOTE: Use of other C-Factor or P-Factor values reported in this table must be substantiated by documentation. (1) Must be constructed as the first step in overlot grading. (2) Assumes planting by dates identified in Table 11-4, thus dry or hydraulic mulches are not required. (3) Hydraulic mulches shall be used only between March 15 and May 15 unless irrigated. (4) Value used must be substantiated by documentation. MARCH 1991 8-6 DESIGN CRITERIA APPENDIX II Table 3-2 Rational Method Runoff Coefficients for Zoning Classifications Table 3-3 Rational Method Runoff Coefficients for Composite Analysis Table 3-3 Rational Method Frequency Adjustment Factors Figure 3-1; Rainfall Intensity Duration Curve • Figure 3-2; Estimate of average flow velocity for use with Rational Formula 0 3.1.6 Runoff Coefficients The runoff coefficients to be used with the Rational Method referred to in Section 3.2 "Analysis Methodology" can be determined based on either zoning classifications or the types of surfaces on the drainage area. Table 3-2 lists the runoff coefficients for the various types of zoning along with the zoning definitions. Table 3-3 lists coefficients for the different kinds of surfaces. Since the Land Development Guidance System for Fort Collins allows land development to occur which may vary the zoning requirements and produce runoff coeffi- cients different from those specified in Table 3-2, the runoff coefficients should not be based solely on the zoning classifications. The Composite Runoff Coefficient shall be calculated using the following formula C = (ECIA,)/A, Where C =Composite Runoff Coefficient CI = Runoff Coefficient for specific area AI A; =Area of surface with runoff coefficient of CI n = Number of different surfaces to be considered A, = Total area over which C is applicable; the sum of all A;'s is equal to A, Table 3-2 RATIONAL METHOD RUNOFF COEFFICIENTS FOR ZONING CLASSIFICATIONS Description of Area or Zoning Coefficient Business: BP, BL........................................................................................ 0.85 Business: BG, HB, C.................................................................................. 0.95 Industrial: IL, IP.......................................................................................... 0.85 Industrial: IG.................:............................................................................. 0.95 Residential: RE, RLP.................................................................................. 0.45 Residential: RL, ML, RP............................................................................. 0.50 Residential: FILM, RMP.............................................................................. 0.60 Residential: RM, MM.................................................................................. 0.65 Residential: RH.......................................................................................... 0.70 Parks, Cemeteries...................................................................................... 0.25 Playgrounds............................................................................................... 0.35 RailroadYard Areas................................................................................... 0.40 UnimprovedAreas...................................................................................... 0.20 Zoning Definitions R-E Estate Residential District — a low density residential area primarily in outlying areas with a minimum lot area of,9,000 square feet. i R-L Low Density Residential District — low density residential areas located throughout the City with a minimum lot area of 6,000 square feet. R-M Medium Density Residential District — both low and medium density residential areas with a minimum lot area of 66,000 square feet for one -family or two-family dwellings and 9,000 square feet for a multiple family dwelling. R-H High Density Residential District— high density residential areas with a minimum lot area of 6,000 square feet for one -family or two-family dwellings, 9,000 square feet for a multiple family dwelling, and 12.000 square feet for other specified uses. R-P Planned Residential District — designation of areas planned as a unit (PUD) to pro- vide a variation in use and building placements with a minimum lot area of 6,000 square feet. R-L-P Low Density Planned Residential District — areas planned as a unit (PUD) to permit variations in use, density and building placements, with a minumum lot area of 6,000 square feet. MAY 1984 3-3 DESIGN CRITERIA R-M-P Medium Density Planned Residential District— designation for medium density variation in use and building placements areas planned as a unit (PUD) to provide a with a minimum lot area of 6,000 square feet. R-L-M Low Density Multiple Family District — areas containing low density multiple family withminimum l0square et units use in iy l asquare feet formultiple-family for one-famy or two-family dwellings M-L dwellings. 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, minimum lot areas equal to 1 /2 of the total including a variety of permitted uses, with floor area of the building. B-P Planned Business District — designates areas planned as unit developments to the surrounding residential areas with provide business services while protecting minumum lot areas the same as R-M. H-B Highway Business District — designates an area of automobile -orientated busi- to 112 of the total floor area of the building. nesses with a minimum lot area equal B-L Limited Business District — designates areas for neighborhood convenience including a variety of community uses with minimum lot areas equal to two centers, 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 floor of the building not to be less than area of lot equal to two times the total area 20,000 square feet. I-P Industrial Park District —designates light industrial park areas containing controlled lot areas equal to two times the total floor area of the industrial uses with minimum building not to be less than 20,000 square feet. 1-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 classifications, refer to the Code of the City of Fort Collins, Chapters 99 and 118. Table 3-3 RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS Character of Surface Runotf Coefficient Streets, Parking Lots, Drives: 0.95 Asphalt................................................................................................ 0.95 Concrete............................................................................................. 0.50 Gravel ............................................ ..................................................... 0.95 Roofs.......................................................................................................... Lawns, Sandy Soil: 0.1 Flat<2%............................................................................................. 0. 5 Average2 to 7%.................................................................................. 0.20 Steep>7%.......................................................................................... Lawns, Heavy Soil: 0.20 Flat<2%............................................................................................. 0.25 • Average 2 to 7%.................................................................................. 0.35 Steep>7%......... :.................................................. ...... ........ ....... ...... ... MAY 1984 3-4 DESIGN CRITERIA 3.1.7 Time of Concentration • In order to use the Rainfall Intensity Duration Curve, the time of concentration must be known. This can be determined either by the following equation or the "Overland Time of Flow Curves" from the Urban Storm Drainage Criteria Manual, included in this report (See Figure 3-2). Tc=1.87 (1.1 —CC,) Di2 ST,3 Where Tc =Time of Concentration, minutes S = Slope of Basin, % C = Rational Method Runoff Coefficient D = Length of Basin, feet C, = Frequency Adjustment Factor Time of concentration calculations should reflect channel and storm sewer velocities as well as overland flow times. 3.1.8 Adjustment for Infrequent Storms The preceding variables are based on the initial storm, that is, the two to ten year storms. For storms with higher intensities an adjustment of the runoff coefficient is required because of the lessening amount of infiltration, depression retention, and other losses that have a proportionally smaller effect on storm runoff. These frequency adjustment factors are found in Table 3-4. Table 3-4 RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORS Storm Return Period Frequency Factor (years) C, • 2to 10 1.0 11 to25 1.10 26 to 50 1.20 51 to 100 1.25 Note: The product of C times C, shall not exceed 1.00 3.2 Analysis Methodology The methods presented in this section will be instituted for use in the determination and/or verification of runoff at specific design points in the drainage system. These methods are (1), the Rational Method and (2) the Colorado Urban Hydrograph Procedure (CUHP). Other computer methods. such as SWMM, STORM, and HEC-1 are allowable if results are not radically different than these two. Where applicable, drainage systems proposed for construction should provide the minimum protection as determined by the methodology so mentioned above. 3.2.1 Rational Method For drainage basins of 200 acres or less, the runoff may be calculated by the Rational Method, which is essentially the following equation: Q=C,CIA Where Q = Flow Quantity, cfs A =Total Area of Basin, acres C, = Storm Frequency Adjustment Factor (See Section 3.1.8) C = Runoff Coefficient (See Section 3.1.6) I = Rainfall Intensity, inches per hour (See Section 3.1.4) 3.2.2 Colorado Urban Hydrograph Procedure For basins larger than 200 acres, the design storm runoff should be analyzed by deriving • synthetic unit hydrographs. It is recommended that the Colorado Urban Hydrograph Procedure be used for such analysis. This procedure is detailed in the Urban Storm Drainage Criteria Manual, Volume 1, Section 4. MAY 1984 - 3.5 DESIGN CRITERIA No Text DRAINAGE CRITERIA MANUAL RUNOFF L] 0 50 30 1— 20 z w U cc w a 10 z w O 5 w cr 3 O U 2 cr I— k: 1 5 a��■������m► �m��■1111 III �I �IIIII� �moll ► 1, ,r I„■""- SEES ONE moll I, ', ■■■■� WA WA ■III IIINII■I.�� I����■■■■� !MISSION :,::':�1 :::lC �...�...FAC-�.1...��C..�011� 2 .3 .5 1 2 3 5 10 20 VELOCITY IN FEET PER SECOND FIGURE 3-2. 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 -1-84 URBAN DRAINAGE & FLOOD CONTROL DISTRICT a N I •i m N r� r b m Vl r F O Yf m 1+1 ••1 P N r P O r m O N O .i (•1 •-1 O W (1 •O •O m O N •-I « O. O r O N ry b rl m Q N O m Q •O b O 1•'1 O '1 O 1/1 W N `G V b F N Y1 10 b r A N N 1•1 t•1 r m Ol O N« d UI N 10 r d m I(1 1!t N 10 N b b b b ID b r F r F r r r m W m m m m m m Ol T m m m m m m a m m m m m m m m m a m m m m a m m m m m m a N 1 •� b N m N I(1 .i 1.1 N N b b O F O d b OI « 01 r N Ol N m O O 1•1 1l1 O w h N OI « Q m r O O .-I N F h m 1•'1 pl -OI b F d Vf 1•1 Q N b m O •O O .] rl w Ill I(1 N 4p •G O N N b b OI « .i N 1.1 Ilf F m F « « N 1'1 1•1 N b N Ill 1l1 N 10 Vf N b IO b lD f0 f0 F h h h r r F r m m m m m m m 01 m Ol Ol T Ol T Ol Ol Ol 01 Ol T Ol T Ol T T T T T Ol Ol T 01 Ol T T T 01 P P d d d Q d P Q d d P P d d P P d P P d d d P d P d P >`. N I•f l•f b Ol T O r Ol lO O1 (•1 ('1 (+1 b Ol q P e1 •-1 Q f0 b O « N Ol m ; O W N N N ill 1Il Ol N N (•f P m .-1 « N N P b F F O O O« 1•1 Ill 1p T (•f N ..� Ul N Yl N Yl Yl b b •O V b F r r r r r r r m m m m m m m m T W m m a a a m m a m m m m a a m m a m m m m a a m m m m m Vl ii a d m d r N 1+f N O d N P I•f r Vl I•f Q N Q m Q •i N Ol N d O O .-I O >• Ol O O 1•f h N r N N •-1 m Ol « •-1 P N Ill pl m 1•f O N 01 T m •-I Ill N F N W d VI N N Ill OI N N ••1 d m m« N N d IO Ip .O OI O O O N d b m N O U a r r'I « b OI F IO T ' OI N Ol l•I Ol Ul Ill N P •G Q m O N O N IO F r ~ •D N Ill Ill 1•1 m m O 01 I.1 d pI r •-1 Ol m r m 10 l•1 1 7 il. O W Q Q Q VI Yl OI 'I .-I N !•f r m O •-I N d Ill 10 IO M1 m Ol pI ry Q N r O O .-1 .i Ilf Ill Yl 1(1 N N IO .O b b b b F r r r M1 r r r r r r m m m m pI ri w O. T 01 Ol Ol Ol P 01 Ol T Ol Ol OI O. N Ol Ol N 01 Ol OI N OI OI Ol Ol Ol 01 Q Q Q Q d d d P P d Q P Q Q P Q d d Q P P Q P Q d Q P d m Q • IYI • d r O 1•f N HI rl b N ri Yl ei O m Yl IO Vl h h O r r I(f O N I•f m O P YI 1% N .-I m« P O O f0 Q V I'I d Q OI I(� •1�' I W l'I l•I I'I d Q m O O '1 N IO r m O N (•1 d IO Vl b h r m N Q N •G b E F N .� vl In In In ul In b b b b b b b F r r r r r r F r r m m m m m < W m m m m m m m m m a m m m m Ol m m m m m m m m m m m m n O P P P Q P d Q d Q Q Q P d P P P d O P Q Q d Q P Q P d d Z O O w O m m m P d O O N d 0 l•1 rl r M1 M1 m« 0 0 N b r O N N 0 0 � �> w W ni O• .-I O O .-1 d r r b m N N N P b m m pI O O N NI N N N f•f N q a W Q YI I!1 Itt Vl N UI N Ill N b b 10 b b b •D b r r r r r m m m m r •wi F m m m m m m m m m m m m m m m m m m m m m m m m m m m m O8r7 m Y G O W Z W N Z O > « Y Y G K C F N 1/1 O O U 4 L OI tr OI N r O Y Y W O M +• m N a U ] 10 w ma V Z z o w w In In m (•I o o In o 0 0 0 0 0 0 o b o 0 0 0 0 0 0 0 In In b n H •. Il1 N m N N OI d OI N 01 r r 11 O N Ill 10 O. P r d Q r m m OI I(I r m m N Q P N 01 r O N d b r rl •i N !•I N O N N F�(L Z « N« N .i N N N N I.1 1'1 1•f t•I 1•f Q I(1 N Ill N N b tp b 1p b r M1 b m V Z O W « m F o 0 o In o 0 0 0 0 o In o 0 0 0 0 0 0 0 0 0 0 o In o 0 0 0 O U a W r m pI pI O« N l•f d VI Ill 10 m OI O« N d I!f r m O N N N (4 b h U VI P Q Q Q Ill 10 10 10 Ill 10 N Ill YI N .O •O IO b. •O .O IO r h r r r r M1 8 • TABLE 11 FLOODWAY DATA Cross 100-year Floodway Width Section Floodplain Elevation (feet) No. Elevation 47.0 4955.8 4956.3 126 48.0 4956.0 4956.5 177 49.0 4956.0 4956.4 174 49.5 4956.2 4956.6 133 50.0 4956.5 4957.0 182 51.0 4960.8 4960.8 70 52.0 4962.7 4963.1 50 53.0 4963.1 4963.0 60 54.0 4965.3 4965.3 ill 55.0 4965.7 4965.7 173 • 55.5 4969.3 4969.5 173 56.0 4971.7 4971.8 186 58.0 4971.8 4971.9 179 59.0 4972.8 4973.3 664 60.0 4973.1 4973.4 152 61.0 4976.0 4975.9 90 62.0 4978.0 4978.2 75 64.0 4978.6 4979.6 220 65.0 4977.8 4980.4 172 67.0 4981.5 4981.5 172 68.0 4982.4 4982.6 50 70.0 4983.6 4983.9 50 71.0 4984.3 4984.5 295 71.5 4984.3 4984.5 295 72.0 4985.3 4985.3 431 73.0 4986.9 4987.3 404 76.0 4992.0 4992.0 404 • 77.0 4995.6 4995'.6 1099 39 1.0 12 10 -� 9 • 11 8 - 10 6 - .8 F- - 0 9 0 4 - .7 x 3 - 8 w a- 6 7 li U - z .5 -- - --e-Part a- .0 5.5 6 ' H w "' 0 z w 5 s W U. .4 U z_ Z .4 ' w z 4.5 0 .3 v U. o 4 x .2 z z c� w '3 3.5 w w a. • a J - o p .I I` w U. o .08 0 .25 3 0 1 0 .06 x x 0 ca 0 U- w w x .04 x 2.5 = a- .03 .2 r c .02 a 2 a U 15 .01 1.5 5 4 3 IL 2 LL i u_ i z 1.5 r 0 T 1.0 z .9 z ------- a_ .8 0 U- 0 7 f- x c� .6 w s p .5 r 0 .4 w F z_ x .25 w I - a 3 w .2 0 x I- n. a .15 w 0 0 Ya -- -- a x We • Figure 5-2 NOMOGRPAH FOR CAPACITY OF from D OP NING INLETS BINS Nomograph DEPRESSION DEPTH 2" A MAY 1984 $-10 DESIGN CRITERIA 1] • rxj 0.7 0.6 r w z 0.5 w > 0.4 0 x r a 0.3 w 0 Z 0.2 0 z 0 • EXAMPLE 2 3 4 PER SO, FT. OF OPEN AREA (CFS/FT2) Figure 5-3 CAPACITY OF GRATED INLET IN SUMP (From: Wright -McLaughlin Engineers, 1969) 5 MAY 1984 5-11 DESIGN CRITERIA n • 10000 9000 6000 7000 6000 5000 4000 2000 1000 900 800 W C \00 6 00 z � 500 c 0 400 Q300 200 100 90 80 70 60 Ai, 20 n From BPR V 2.0 r - L (...TIES: 0. 1.,, (A) S� , n .$ So .... ICI GOIIIIGI(,r IN ....INS .IO Ill ... 1. o1.01n.r( TO Yul➢I.I I, .0110. OI 1.....I 1.0 ( IS .11I10IEC.I a uas SLOPE .08 a11.[N E! I. I.. r.aaw,es I«.. .07 r.E[ no, Eno.TwN u•, .80 06 .70 EXAMPLE(SEE ou Nto L. � .05 100 .60 To \ I . 14 E/n . IEoo LL so �; .04 .50 IT • 0. U- -- .03 .40 to 2 ---..e_.-===_-`- T - _ Z Z -.30 S .02 T I ( s U 3 w .z INSTRUCTIONS (7 I J .01 w�( NOT tyJ I, CONNECT t/IT ..n0 LAITY 11EIC S. •.Q Nos .NE cI ox+(cr I�sc..+EI .....l. _.. .o: Z .008 ov1vl r.[S1 r.O 1.I...v Ci 0 Q .007 I.T1n11CT .1 1...... 1.1 To. V) = CO.IItlI sow no. 0 .oI `\, 9 .006 E. row aY.uO. I` _.005 LL C....11 0 \ .s ,.o.r 1., IONIC.... 004 w a 0 .003 S 10 On u.IIE r J NEC .... 1 0, �, N romo. 01 1.... IL ou u.In EOT. 11.. 1E1.1 Ilsc.... 1 Ir .002 (.TINE SECTION a TNE. OS1 IOY01..1. TO I[t[N Yi,t O IN IEIIIIN N 1.. .111. . TO IETEIYINE 04St.uGE IN CONrourt SECTION•- SEI.E. 'ISu.c,Il+ , l� l .001 Ov1Y ,: Ou.ue ,1OI( ..1.0 1, .No III'- i "1. 0,. 0,.or Figure 4-1 NONOGRAPH FOR FLOW IN TRIANGULAR GUTTERS (From U.S. Dept. of Commerce, Bureau of Public Roads, 1965) F .20 Y, U) .10 LL) OL .08 w w .07 0 06 fY 0 k.05 m Cr .04 U .03 Q 2 ~ .02 a w 0 ME MAY 1984 4-3 DESIGN CRITERIA 0 APPENDIX III STUFFER ENVELOPE Drainage and Erosion Control Plan Exhibit A Erosion Control Security Deposit estimates March 9, 1994 Project No. 1450-01-94 Basil Hamdan City of Fort Collins Storm Water Utility P.O. Box 580 Ft. Collins, Colorado 80522 Re: Spring Hollow Minor Subdivision; Fort Collins, Colorado Dear Basil, Attached is the erosion control security deposit estimate for Spring Hollow Minor Subdivision. ESTIMATE 1: 535 LF of silt fence at $3.50 per LF $ 1,872.50 2 Gravel inlet filter at $75.00 each $ 150.00 TOTAL ESTIMATED COST: $ 2,022.50 x 1.50 S 3,033.75 ESTIMATE 2: re -vegetate the disturbed area of 1.934 acres at $650.00 per acre $ 1,257.10 TOTAL ESTIMATED COST: S 1257.10 x 1.50 S 1,885.65 The total required erosion control security deposit will be $ 3,033.75. If you have Brian W. Shear, P Shear Engineering Corporation please call at 226-5334. BWS / mb • cc: William Coulson Dave Stringer; City of Fort Collins Engineering 4836 S. College, Suite 12 Fort Collins, CO 80525 (303)226-5334 r� March 9, 1995 Project No. 1450-01-94 Re: EROSION CONTROL SECURITY DEPOSIT REQUIREMENTS: Spring Hollow Minor Subdivision; Fort Collins, Colorado A. An erosion control security deposit is required in accordance with City of Fort Collins policy (Chapter 7, Section C : SECURITY; page 7.23 of the City of Fort Collins Development Manual). In no instance shall the amount of the security be less than $1000.00. 1. According to current City of Fort Collins policy, the erosion control security deposit is figured based on the larger amount of 1.5 times the estimated cost of installing the approved erosion control measures or 1.5 times the cost to re -vegetate the anticipated area to be disturbed by construction activity. a The cost to install the proposed erosion control devices for Spring Hollow Minor Subdivision is $ 2,022.50. 1.5 times this estimate is $ 3,033.75. i. unit prices have been provided by Connell Resources. • b. Based on current data provided by the City of Fort Collins Storm Water Utility, and based on an actual anticipated net affected disturbed area during construction of Spring Hollow Minor Subdivision (approximately 1.934 acres) we estimate that the cost to re -vegetate the disturbed area will be $ 1257.10 ($650.00 per acre x 1.934 acres). 1.5 times the cost to re -vegetate the disturbed area is $ 1,885.65. i. The 1.934 acres is the actual area of Spring Hollow Minor Subdivision. ii. The $650.00 per acre for re -seeding sites of less than 10 acres was quoted to us by the City of Fort Collins Storm Water Utility staff. • CONCLUSION: The erosion control security deposit amount required for Spring Hollow Minor Subdivision will be $ 3,033.75. 4836 S. College, Suite 12 Fort Collins, CO 80525 (303)226-5334 0 MEMORANDUM OF UNDERSTANDING William A Coulson is the developer of certain real property located in the City of Fort Collins known as SPRING HOLLOW MINOR SUBDIVISION. The City has approved an Erosion Control Plan dated March, 1995 and, pursuant to Section 2.2 of the City's Storm Drainage Criteria ("the Criteria"), the City has agreed to accept a bond, cash escrow, irrevocable letter of credit in the amount of $ 3,033.75 ("the $ 3,033.75 Escrow") from the Developer to guarantee the proper installation and maintenance of the erosion control measures shown on the Plan and described in the Criteria. The $ 3,033.75 Escrow has been received by the City. If, at any time, the Developer fails to abide by the provisions of the Plan or the Criteria, the City may enter upon the premises known as SPRING HOLLOW N13NOR SUBDIVISION for the purpose of making such improvements and undertaking such activities as may be necessary to ensure that the provisions of the Plan and the Criteria are properly enforced. The City may apply such portion of the $ 3,033.75 Escrow as may be necessary to pay all costs incurred by the City in undertaking the administration, construction and/or installation of the erosion control measures required by the Plan and the Criteria. Upon acceptance by the City of the initial installation of the erosion control measures required by the Plan and the Criteria, the $ 3,033.75 Escrow shall be reduced to twenty-five percent (25%) of the actual cost of such measures. The balance of the $ 3,033.75 Escrow shall be held by the City to guarantee the continued maintenance and replacement of such measures for a period not to exceed two (2) years from the date of installation of the erosion control measures. . Upon the expiration of said two (2) year period, or the date of certification by the City that the required measures have been fully completed and maintained in accordance with the Plan, whichever occurs first, the balance of the $ 3,033.75 Escrow shall be refunded to the Developer and the right of access granted to the City under this Memorandum of Understanding shall be of no further force and effect. Until such time, the rights of the parties under this Memorandum of Understanding shall run with the property and be binding upon any subsequent owner thereof, as well as any assignee in interest of the Developer. Dated this day of 1995 DEVELOPER: THE CM OF FORT COLLINS COLORADO, a municipal corporation William A. Coulson 221 Mathews Street #20 Ft. Collins, Colorado 50524 By: Project Representative By: Glen D. Schlueter, Development Review Manager u 11 IS i !I. i� r r �.• II Is , 3 p I tea, .» .... «. Am Ot » >r. .r OR r K•» �. 2.10 'A Ali MOR Rule I h —1, I Auwt IAt. All. an «A «A .» F __f_ I I z a- I\ I j III i SPRING CREEK COUNTRY DAY SCHOOL /P. II' """ """ "'« "« `« "» ".. '.•' '.•• " ".»'« N a \4980 ° I 4- VALLEY PAN , I; w I j I I Ift..... C Y i _, — _ _ _ f r P 364 . A» H». I OIIAYEL INLET PILTFRj {Y . w z I -� 4• curl ovoxlt�o IO II 0 i 17 > m I _ _ __1 t SILT FENCE, Tn. d, SECTION A -A 3:'jxFA` Ftt Pet n Fxr. s i I M j A' FtT1ewA+ cuLgR11 1 t ,1 ril FCE DETAIL ENT. s v.zo.an %I i •.•> •.» •.r...» r.» ..« >.>r ..« ..« ..» .._ ...,. PE II 1 N E953'00- w 295.3T 11 I I - tFE OETAFNtM. • I! I Oltwft aw, New so } I _ w �levelsr. E � w .r. °» I t I ................................................ ........ 8 1 Ag 1 myyi -4982 J __ n fR r. IC ... ... •» •« .» 1.41 .» J i z x Sell: If.60 I I „ .... .... ... .... RAW a:sl.. r.x m..,a .... t I I 17 kl 1-.-e2 .,. we, °.«,,...., ,a.,m ..,.,. ,,....M «,«... »«., r.r,,.e _ )/ i o,I W ><: .. F1 ___-- I c9N„Eumn II W 0 j J Eo I .. i� '< i •. :KS � L• rr: s:.Iao e= Pf: 4b »'. t , u. P l! P.w.eI. „wn. nou %V « RA.A.pE N II N :a IC\_�,. )'t 'i'; ',SA .EwIO.ve ONLY c'gMYdA�' EDy. r» SAN .« AVON + W ;I rr ..w a------' °° t+ , SPRING CREEK PARK r WAR a .a I ,�, .ow .....,» MaYW�i2QrtAA.flltm , ,„f ill aft 4 Ate. ::.r.�...r: I M-wa •. k' / eo/ �" 'q`»r� ``t \ .=.. N°�r:...p:•7w._,rr I j� ���11�E«.° s>,o O t e' / ,i h •,l 1 ... E ArKi "Aft e' 'y V • 6 \n •fe e' 6 he �� bk' \ \ O , i a• F� 2 `' _ ___ _ _ \\ �,. . rn ..r.n J� ..A•� \ R 3 au_wART AND QIAYr E.a Yam. �NN.`wY. I t 0 �r ` •� LL, �\- as AD- Lp `°`� v h "�SArm•\ -- ».ur` A i� i e.w 20 FORD ral I i, ii ER •• - b ' !O ) ♦ 1�c '- Y � 'r �,^a \-ee 49 Y '1 D 9�8� E N 4 boa r NO, - -' J.. ©\ SECTION 0-0 ��/! bb.� ,b A`, l �A•A` vIOSF FROM .9w ro m% it I _ v avi -9E ~i fV sruc f=m ;� 0--, �.� ` \ N S qq H \ - THE SHERF(N10 IRRIGATION COMPANY APPROVAL !T P NEq WO T (/q OAT _ \ \r>t �� ,gip ` .� ±I GO qTC B C - \ \ \ t r,` ��R11i',���an _ ,F .-_` O,MA / My of Fort CollioE, Colorado ARY1^R% gNYI �\ VNIR PLAN APPROYA MoN GGG/// -`-',.EASEJAENr ArFlom sowm.K »» » ��' c1Fam Fr N� (01(10�1101---'t'`, CHECKED R R-OWDIRICTION�`. -`—�;'���- \ -._--- CHECKEDR We STRAW BALE DIKE \\ "->,� CNFCFFOR r c CHECKED BF xnsmxs DIN fEFRU�ARr 199s Fw.A cAONaE 9N0 SHEAR ENGINEERING CORPORATION '� DRAINAGE AND EROSION CONTROL PLAN mo,Ec1 No. E»Ec >„_ Of— ppp1p0on pH bee [NwYee B.W.S. BILL COUISON Ali SO. COIAECE AVE. SUITE 12. FORE COILINS, eoluFAm 80525 SPRING HO OW MINOR SUBDMSION O ob. M ov0an - v ow N �� 5yy I' = 20' AppweE F.W.S. PHONE: (303) 226-533A (301) 228-4451 FO COLLIN3, COLONADO 1450-01—E4