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HomeMy WebLinkAboutST. PETERS ANGLICAN CHURCH - PDP/FDP - FDP150040 - REPORTS - DRAINAGE REPORTFinal Drainage and Erosion Control Report for ST. PETER’S ANGLICAN CHURCH Fort Collins, Colorado January 27, 2016 January 27, 2016 Mr. Shane Boyle City of Fort Collins Water Utilities--Storm water 700 Wood Street Fort Collins, Colorado 80521 RE: Final Drainage and Erosion Control Report for Saint Peter’s Anglican Church Dear Wes: We are pleased to submit to you, for your review and approval, this revised Final Drainage and Erosion Control Report for Saint Peter’s Anglican Church. All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. We appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Respectfully, Aspen Engineering John Gooch, P.E. Principal TABLE OF CONTENTS DESCRIPTION PAGE I. GENERAL LOCATION AND DESCRIPTION 5 A. LOCATION 5 B. DESCRIPTION OF PROPERTY 5 II. DRAINAGE BASINS 6 A. MAJOR BASIN DESCRIPTION 6 B. EXISTING SUB-BASIN DESCRIPTION 6 C. PROPOSED SUB-BASIN DESCRIPTION 7 III. DRAINAGE DESIGN CRITERIA 8 A. REGULATIONS 8 B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS 8 C. HYDROLOGIC CRITERIA 8 D. HYDRAULIC CRITERIA 9 E. VARIANCES 9 IV. DRAINAGE FACILITY DESIGN 9 A. GENERAL CONCEPT 9 B. SPECIFIC DETAILS 10 C. DETENTION POND 13 D. STREET CAPACITIES 13 V. STORM WATER QUALITY 13 A. GENERAL CONCEPT & SPECIFIC DETAILS 13 VI. EROSION CONTROL 14 A. GENERAL CONCEPT 14 VII. CONCLUSIONS 15 A. COMPLIANCE WITH STANDARDS & STORMWATER 15 OPERATIONS/ MAINTENANCE PROCEDURE B. DRAINAGE CONCEPT 15 C. STORM WATER QUALITY 16 D. EROSION CONTROL CONCEPT 16 E. EROSION CONTROL ESCROW ESTIMATE 16 REFERENCES 17 APPENDIX PAGE VICINITY MAP A EXCERPTS FROM Filing 2 and 3 DRAINAGE REPORTS B POND 306 VERIFICATION CALCULATIONS C RATIONAL METHOD HYDROLOGY CALCULATIONS D WEIR AND SWALE CALULATIONS E LID RAIN GARDEN CALCULATIONS AND COMPLIANCE AND EROSION CONTROL ESCROW CALCULATIONS F PROPOSED & EXISTING DRAINAGE BASIN EXHIBITS, EROSION CONTROL PLAN, & EROSION CONTROL NOTES AND DETAILS SHEET SEE POCKET AT BACK 5 FINAL DRAINAGE AND EROSION CONTROL REPORT FOR SAINT PETER’S ANGLICAN CHURCH FORT COLLINS, COLORADO I. GENERAL LOCATION AND DESCRIPTION A. Location The Saint Peter’s Anglican Church project is located a quarter of a mile west of the Trilby Road and Lemay Road intersection, in Lot 1 Block 14 of Provincetowne Filing 3, which is within the northeast quarter of Section 13, Township 6 North, Range 69 West. Lot 1 is bounded by Trilby Road on the north, Brittany Drive to the east, Candlewood Drive to the south and Autumn Drive to the west. The Project area is 4.98 acres +/-, refer to the vicinity map located in Appendix A. B. Description of Property The project site was originally developed as Tract A in Provincetowne PUD Filing 2 and was subsequently re-platted as lot 1, Block 14 in the Provincetowne PUD Filing 3. Prior to the St Peter’s developing the site, the site was being planned for commercial and day care use. An existing detention pond is also located within the site adjacent to Brittany Drive within the eastern portion of the site. The detention pond (Pond 306) serves Provincetowne PUD Filings 2 and 3. The site is the only undeveloped portion of Provincetowne PUD remaining and has all adjacent roads and storm infrastructure constructed on its boundaries and as previously noted detention Pond 306 is fully constructed with mature trees and wild grasses. The site topography generally slopes from south to north and then west to east to Pond 306 on the eastern side of the site. The remnants of a parking lot for a sales trailer is located on the south west portion of the site, there is no other existing hard area currently on the site. The southern and western portion of the site is graded to drain to the north at approximately 2%. The graded area rises above Autumn Ridge Drive and Trilbly Road as it goes north. As this graded area rises steeper slopes are created to the west and north. At the toe of the northern slope is a 50 foot wide flat area adjacent to Trilby road. This flat area drains to the east and north culminating in a shallow swale at its eastern extents to drain the storm water to Pond 306. 6 Pond 306 is a fully developed detention pond that is used by Filings 2 and 3 as well as Lot 1. Adjacent to Pond 306 a 7 foot high mound of excess material is located to the west of the pond. The entire site is now covered in tall grass from previous erosion control measures with mature trees located in the detention pond and street trees spaced around the perimeter of the site. II. DRAINAGE BASINS A. Major Basin Description The Saint Peter’s Anglican Church project site is located within the Stone Creek drainage basin which is a sub-basin of the Fossil Creek Basin. Therefore this project will conform to the Fossil Creek Basin Master Plan as well as the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3, November 10, 2006 (see App B). Originally the drainage for this site was set out in the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 2, March 22, 2001 (see App B) which shows all of the storm water flows draining to pond 306. The impervious coefficient for Tract A was set at 49%. Tract A was then re-platted as Lot 1, Block 14 of Filing 3. In the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3, November 10, 2006 the percent impervious was modeled as 45%. In this report it is stated “Because the new design does not adversely impact the detention pond and only improves upon it, the detention pond will remain untouched. It is the intention of this design to not to exceed the percent impervious of 45 percent and to conceptually match the drainage pattern as set out on drawing 94 of 99 of Provincetowne PUD Filing 2 (See App B). B. Existing Sub-Basin Description The existing sub-basins will be based on the previously mentioned drawing 94 of 99 (See App B) from the Provincetowne PUD Filing 2 Final Drainage and Erosion Report. This is because these basins were used to size the now constructed pipe infrastructure, inlets and Pond 306. This means that even though the existing condition (drainage basins) today does not match the above mentioned basins, there is no advantage to calculating current existing flows as they will have no bearing on the allowable flows or infrastructure sizing. Please note that the existing percent impervious for all basins is now 20 percent (including surrounding existing roads) and in the future condition will not be as shown on drawing 94 but as 45 percent as 7 stated in the Final Drainage and Erosion Report for Provincetowne PUD Filing 3 (See Appendix B). Basin 212 (Refer to Provincetowne PUD 2nd Filing Sht 94, App B) Basin 212 is 1.24 acres (note that on the original drawing 0.46 acres was called out, this is not correct) in area and drains west onto Autumn Ridge Drive to inlet 5B which discharges the storm water to a 36 inch diameter storm drain which empties into the north west corner of Pond 306. Basin 225 (Refer to Provincetowne PUD 2nd Filing Sht 94, App B) Basin 225 is 1.09 acres in area and drains north onto Candlewood Drive to inlet 4B which discharges into a 42 inch diameter storm drain which empties into the north end of Pond 306 Basin 220 (Refer to Provincetowne PUD 2nd Filing Sht 94, App B) Basin 220 is 1.07 acres in area and drains to the north onto Trilby Road to an existing inlet. Basin 406 (Refer to Provincetowne PUD 2nd Filing Sht 94, App B) Basin 406 is 0.92 acres in area and drains north east to a shallow swale that slopes to the east and discharges storm water into Pond 306. Basin 221 (Refer to Provincetowne PUD 2nd Filing Sht 94, App B) Basin 221 is 1.64 acres in area and drains north and east by overland flow into the eastern slope of pond 306. C. Proposed Sub-Basin Description The proposed sub-basins are numbered 1-8 for the entire site, with sub-basins 1, 2, 4 and 7 being affected by the development. The remaining basins have no additional impervious area added to them by the development. Sub-Basin 1 will drain onto Autumn Ridge Drive to an existing inlet (DP1) with an area similar to the previous design. Sub-Basin 7, which consists for the majority of the new hard surface area will drain north to an LID Basin (DP7) and swale in Sub- Basin 4. Sub-Basin 4 will convey flows via a swale to an existing swale (DP4), the existing swale coveys these flow to the existing detention pond 306. 8 Sub-Basin 2 has overland storm flows which spill directly onto Trilby Road Basins 3, 5, 6 and 8 remain unchanged with grassy areas discharging by overland flow to adjacent roadways and then to Detention Pond 306. III. DRAINAGE BASIN CRITERIA A. Regulations The drainage design for the subject site is required to meet the current City of Fort Collins Stormwater and Erosion Control Standards and requirements. The drainage criteria for this Site is also set out in previous Final Drainage and Erosions Control Reports for the Provincetowne Filings 2 and 3. Originally the drainage criteria and design for this site was set out in the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 2, March 22, 2001 (see App B) will all of the storm water flows draining to pond 306 with the impervious coefficient for Tract A was set at 49%. Tract A was then re-platted as Lot 1, Block 14 of Filing 3. In the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3, November 10, 2006 the percent impervious was modeled as 45%. In this report it is stated “Because the new design does not adversely impact the detention pond and only improves upon it, the detention pond will remain untouched. It is the intention of this design to not exceed the percent impervious of 45 percent and to conceptually match the drainage pattern as set out on drawing 94 of 99 of Provincetowne PUD Filing 2. B. Development Criteria Reference and Constraints The criteria and constraints from the City of Fort Collins will be met. Requirements for the site allow for a maximum percent impervious of 45% as noted in the PDR comments (ref no. PDR140010, dated Dec 22, 2014) C. Hydrologic Criteria The Rational Method for determining surface runoff was used for the project site. The 2-year and 100-year storm event intensities were used in calculating runoff values. The City of Fort Collins intensity duration frequency curves were used to obtain rainfall data for each storm specified. BMP’s and LID measures are being incorporated into the proposed grading and drainage development plans. 9 Detention and water quality pond sizing were previous calculated using SWMM modeling as stated in the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3, November 10, 2006. D. Hydraulic Criteria All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are also included in the Appendix. Final storm sewer pipe and inlet/curb cut sizing has been completed using UDSewer and UDInlet from UDFCD, as well as other orifice/inlet control sizing spreadsheets. Final erosion control and riprap sizing calculations have also been completed using North American Green software and other software. E. Variances No Variances are requested. IV. DRAINAGE FACILITY DESIGN A. General Concept Eight proposed drainage basins will provide conveyance of drainage to the existing Detention Pond 306. Detention Pond 306 will remain unchanged as the Site was part of the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3, where the site was approved with a 45% impervious area. This site has a hard area of 35% and an impervious coefficient of 0.45 (See Rational calculations App D), therefore complies with the 2nd Filing drainage report and City of Fort Collins PDR comments. The proposed site improvements consist of a church building and a parking lot with two entrances. The roof drainage will discharge to splash blocks where practical then to the ground. The parking lot will drain from southwest to northeast. Sheet flow from the south parking lot will be treated with porous pavers with an under drain system discharging to the existing swale. Runoff from the parking lot will flow to a curb cut in the traffic circle and get treated in an LID pond then to a swale which drains north and then east along Trilby Road to existing Pond 306. Pond 306 has been designed with extended detention, which includes this site in the developed condition in its catchment area. Please refer to the rational calculations in Appendix D and the Existing and Proposed Drainage Basin Exhibits in Appendix G for additional information. 10 B. Specific Details Sub-Basin 1 Sub-Basin 1 drains storm water from south to north on Autumn Ridge Drive to an existing inlet 5B (DP1) then to an existing inlet in Trilby Road. The flowrates for (DP1) are as follows; Q2=1.24 cfs and Q100 = 5.77 cfs. The Street Capacity at this point is as follows; Minor Storm capacity = 14.8 cfs and Major Storm capacity = 43.1 cfs. Because the previously designed basin and this proposed basin are similar in size there is no adverse impact to the drainage system. Sub-Basin 2 Sub-Basin 2 drains the grassed area north of the church and some of the playground area onto Trilby Road to (DP2), the storm water then is conveyed by curb and gutter to another inlet to the east at (DP3) where water is then drained to existing Pond 306. Sub-Basin 2 has an area 0.42 acres and a drainage coefficient of 0.25. Originally the drainage design from the 3rd Filing directed 1.07 acres onto Trilby Road. The proposed Sub-Basin design directs only 0.42 acres onto Trilby Road with the other area from new Sub-Basins 7 and 4 being directed to the existing swale south of Trilby Road, which drains into Pond 306. The flowrates for Design Point 2 are as follows; Q2=0.23 cfs and Q100 = 1.06 cfs. Sub-Basin 3 Sub-Basin 3 is an existing condition that is different from the original design. The Filing 3 design shows all flows that were in Sub-Basin 3 flowing away from Trilby Road. The topographic survey shows this small grassy area draining onto Trilby Road (DP3) then to a curb inlet. Sub-Basin 3 has an area 0.20 acres and a drainage coefficient 0.25. The flowrates for (DP3) are as follows; Q2 = 0.08 cfs and Q100 = 0.35 cfs. It is felt that this would have no adverse effect on the hydraulic capacity of Trilby Road. Sub-Basin 4 Sub-Basin 4 drains 75% of the roof area through a roof drain to the soft pan LID swale , a small area of hardscape and a grassed area just south of the main parking lot and has an area of 0.41 acres and a drainage coefficient of 0.56. Sub-Basin 4 is located downstream of Sub-Basin 7. Sub-Basin 7 discharges all of its flows through a 12’ wide curb cut (DP7) into a LID rain garden basin that overflows into a swale that is in Sub-Basin 4. The flowrates for (DP4) as routed from Sub-Basin 7 are as 11 follows; Q2 = 2.46 cfs and Q100 = 10.99 cfs. The design flow for the swale in Sub- Basin 4 is 10.99 x 1.33 = 14.62 cfs. The 1.0 foot deep triangular swale which has side slopes of 5:1 and 10:1 and a longitudinal slope of 3.0% will carry the design flow at a depth of 0.68 ft deep. Refer to swale calculation in Appendix E. Sub-Basin 5 Sub-Basin 5 drains a grassed area from south to north to a swale that drains storm water from west to east which then discharges to Pond 306 in Sub-Basin 6 and has an area 0.57 acres and a drainage coefficient of 0.25. Sub-Basin 5 is located downstream of Sub-Basin 4 (DP4). The swale from Sub-Basin 4 discharges into the existing swale in Sub-Basin 5. A LID soft pan 3.0’ wide and 234’ long is proposed to be constructed within the existing swale. The design flow for (DP5) as routed from Sub-Basins 4, 5 and 7 are as follows; Q2 = 2.66 cfs and Q100 = 11.89 cfs. The design flow at Design Point 5 is 11.89 cfs x 1.33 = 15.82 cfs. A cross section for the swale is estimated to be trapezoidal with a 5 foot bottom width, 4:1 side slopes with a longitudinal slope of 2.00%. The cross section is taken 70 feet down stream of (DP5) where the swale cross section appears to be the most restricted. Calculations (See Appendix E) show a depth of 0.55 for the design flow, well within the estimated 1 ft depth of the swale. Sub-Basin 6 Sub-Basin 6 consists of a grassed area that drains directly to the existing Detention Pond 306 and has an area of 1.45 acres and a drainage coefficient of 0.25. The main feature of Sub-Basin 6, Detention Pond 306, was constructed with Provincetowne PUD Filing 2 and receives storm water from this site, the Filing 2 and 3. The City of Fort Collins has requested that we check that the volume of the Pond is consistent with the original design. See Section C below for a discussion of the results of the volume check. As noted below, there will be no changes to the detention pond required. Sub-Basin 7 Sub-Basin 7 is comprised of the parking lot and drive isles, a portion of the proposed building, some hardscape and a small amount of landscaping. Sub-Basin 7 drains from southwest to northeast across the parking area where storm water is conveyed in curb and gutter to a 12’ wide curb opening (See App E for weir calculations) at the north side of the circle drive (DP7). Run off discharges to an LID Basin which overflows into a swale in Sub-Basin 4. Sub-Basin 7 has an area of 1.18 acres and a drainage coefficient of 0.76. Porous Paving constructed in Sub-Basin 7 will treat runoff and meet the 25% porous paving requirement. The design flows at (DP7) is as follows; Q2 = 2.00 cfs and Q100 = 9.20 cfs. 12 Sub-Basin 8 Sub- Basin 8 drains a grassed area and sidewalk onto existing Candlewood Drive where drainage flows from west to east to an existing storm drain inlet. No changes from the previous condition are proposed. Sub-Basin 8 has an area of 0.95 acres and a drainage coefficient of 0.49. The design flows at (DP8) are as follows; Q2 = 1.25 cfs and Q100 = 5.66 cfs. The street capacities for Candlewood Drive are as follows; Minor Storm = 14.8 cfs and Major Storm = 30.5 cfs. Overflow Conditions Sub-Basins 1, 2, 3, and 8 These are existing conditions that will operate similarly to what they have before and as stated in the previous drainage reports for Filings 2 and 3 of Provincetowne PUD. Sub-Basin 7 The overflow from Sub-Basin 7 would occur at the weir at Design Point 7. In an overflow condition, flows will overtop the curb and flow to the swale in Basin 4 with no impact on the church building or any other residences. Sub-Basin 4 The overflow condition in Sub-Basin 4 would occur if the capacity of the swale is exceeded due to a greater than 1 in 100 year storm event. Flows that exceed the capacity of the swale will still flow to the swale in Basin 5 and possibly onto Trilby Road. These flows would then travel to an inlet which discharges into Detention Pond 306. It is unlikely that any significant property damage would occur. Sub-Basin 5 Similar to Sub-Basin 4 an overflow condition would occur if the capacity of the swale is exceeded in an extreme event. In which case storm flows would flow onto Trilby Road and then back into Detention Pond 306. It is unlikely that any significant property damage could occur. 13 Sub-Basin 6 Sub-Basin 6 contains existing Detention Pond 306, which was previously designed and built as part of Provincetowne PUD Filing 2. As this project fits within the design criteria of Filing 2 as the same analysis from the original report will hold. C. Detention Pond Existing Pond 306 A volume check of the existing detention pond 306 was completed per City of Fort Collins request. In checking the original design we referred to the Pond 306 rating curve from the 3rd Filing drainage report completed by JR Engineering (See App C). The topographic survey was used to create a depth volume table and this was compared to the original Pond 306 rating curve. In comparing the two pieces of information it was found that two different elevation datum were used. This was noted and adjusted in the spreadsheet calculations (See App C). The calculations show that the surveyed Pond 306 has a similar capacity to that in the original design. At elevation 4949.35(original datum) the surveyed volume was 2.443 acre-feet vs the rating curve volume of 2.60 acre-feet for a 6% difference. The surveyed storage volume at the spillway elevation of 4949.60 is 2.629 acre-feet, which is slightly greater than the required design volume. D. Street Capacities The Saint Peter’s Anglican Church Project will not adversely affect the adjacent street capacities as this development is in compliance with the in the Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3. Street Capacity Calculations are provided in Appendix D. V. STORM WATER QUALITY A. General Concept & Specific Details General Concept The water quality of stormwater runoff must be addressed on all final design utility plans. Therefore, Best Management Practices (BMP's) for the treatment of stormwater runoff for the subject site will include grass swales, porous pavers, LID rain garden basin, a 3’wide by 250’ long soft pan swale, riprap pads at the curb cut discharge point and permanent erosion control fabric. These proposed water 14 quality features will provide a mechanism for pollutants to settle out of the stormwater runoff before flows are directed downstream to the existing detention pond and ultimately to the Poudre River. The proposed rain garden/ LID basin, the 250 feet of existing grassed swale with soft pan bottom provide good sediment and pollution removal. Please note that no extended detention structure is constructed in the bottom of Pond 306. In lieu of constructing a new extended detention structure nearly all of the new hard surface area (98%) will be treated with LID measures. Specific Details LID measures will be implemented to treat 98% of the newly developed impervious area, approximately 0.50 acres will runoff to the rain garden basin and 0.39 acres will run on to the porous pavement. The rain garden basin (See Appendix F for calculations) will pond to a depth of 1 foot before over flowing to 50’ of new grass lined swale and 234’ of existing grass swale with the 3’ wide soft pan. Approximately 0.17 acres of hard surface area will drain to the 3’ wide soft pan. VI. EROSION CONTROL A. General Concept The subject site lies within the Moderate Rainfall Erodibility Zone and the Moderate Wind Erodibility Zone per the City of Fort Collins zone maps. The potential exists for erosion problems during construction, but should be minimal after completion of proposed development. Silt fence will be installed along the north, south east, and west sides of the site to prevent sediment from leaving the site. A vehicle tracking pad will also be placed at the south entrance to the site as shown on. Gravel inlet filters will be installed at existing inlets in public streets around the perimeter of the site. Riprap and erosion control fabric will be constructed at the proposed curb cut to prevent erosion of the swales. Straw wattle check dams will also be installed in the existing grassed swale along Trilby Road at intervals as applicable. Please refer to the Erosion Control Plan and Erosion Control Notes and Detail Sheets in the map pocket at the back of this report. 15 VII. CONCLUSIONS A. Compliance with Standards & Stormwater Operations/Maintenance Procedure All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. The City of Fort Collins Storm water Utility will not maintain the on-site storm drainage facilities within the subject site. The owners of the subject site will maintain their on-site storm drainage facilities on a regular basis. The following shall be implemented for the private stormwater improvements’ operations/ maintenance procedures for the project on an annual or bi-annual basis: 1) Curb cuts and concrete sidewalk culverts/chases, and the outlet control structure shall be cleaned through the removal of debris and sediment from the associated items to allow for adequate drainage through the site to the proposed detention facility 2) Pond sedimentation/ silting shall be removed to allow for adequate drainage along the bottom of the pond and to prevent ponding and silting in of the pond bottom. Grass scrubbing along the bottom of the pond may be required to remove sediment and promote grass growth 3) Re-vegetation through the use of Natural Seeding/ Sod shall be provided for disturbed areas and other permanent erosion controls shall be provided for areas where erosion has taken place and requires remediation back to the proposed condition shown in the plans The Stormwater Operating/ Maintenance Procedures listed above are guidelines to the minimum procedures that shall be implemented for the site, with these and additional measures being utilized on an as-needed basis. B. Drainage Concept The proposed drainage concepts presented in this study and shown on the utility plans, adequately provide for the transmission of developed on-site runoff to the existing detention pond (Pond 306), located in the eastern portion of the subject site. The proposed storm drainage system will provide for the 100-year developed flows to reach the existing water quality and detention ponds, prior to flows being released downstream. The site impervious area is 35% which is less than the designed impervious area of 45%, therefore fits within the drainage design of Provincetowne 3rd Filing. 16 If groundwater is encountered at the time of construction, a Colorado Department of Health Construction Dewatering Permit will be required. C. Storm Water Quality The final design has addressed the water quality aspect of stormwater runoff. The proposed rain garden LID basin, 234 lf of grassed swale with a 3’wide soft pan, and the porous pavement will provide an opportunity for stormwater pollutants to filter out of the stormwater runoff before flows are directed downstream. The proposed soft pan grass lined swale, rain garden LID basin, riprap, permanent erosion control fabric and other erosion control devices that may be utilized for side- slopes and embankments, grass scrubbing across the bottom of the detention pond during first flush conditions, will provide additional mechanisms for pollutants to settle out of the stormwater runoff before flows are directed south to Fossil Creek Reservoir and ultimately into the Poudre River. D. Erosion Control Concept Proposed erosion control concepts will adequately provide for the control of wind and rainfall erosion from the proposed development. Through the construction of the proposed erosion control concepts, the City of Fort Collins standards will be met. The proposed erosion control concepts presented in the Final report and shown on the erosion control plan are in compliance with the City of Fort Collins Erosion Control Criteria. E. Erosion Control Escrow Estimate The Erosion Control Escrow Estimate for the subject property is approximately $8,439.00. 17 REFERENCES 1. Storm Drainage Design Criteria and Construction Standards by the City of Fort Collins, Colorado, May 1984, Revised January 1997, & Associated UDFCD Updates and New City of Fort Collins Stormwater Criteria manual, adopted January, 2012. 2. Erosion Control Reference Manual for Construction Sites by the City of Fort Collins, Colorado, January 1991, Revised January 1997, & Associated UDFCD Updates and New City of Fort Collins Stormwater Criteria manual, adopted January, 2012. 3. Urban Storm Drainage Criteria Manual Volume 1; Urban Drainage and Flood Control District, Denver, Colorado, March, 1969. 4. Urban Storm Drainage Criteria Manual Volume 2; Urban Drainage and Flood Control District, Denver, Colorado, March, 1969. 5. Urban Storm Drainage Criteria Manual Volume 3, Best Management Practices; Urban Drainage and Flood Control District, Denver, Colorado, September, 1999. 6. City of Fort Collins Website, Fossil Creek Drainage Basin Master Plan, http://www.fcgov.com/utilities/what-we-do/stormwater/drainage-basins 7. Final Drainage and Erosion Control Report for Provincetowne PUD Filing 2, Manhard Consulting Ltd, March 22, 2001. 8. Final Drainage and Erosion Control Report for Provincetowne PUD Filing 3, JR Engineering, November 10, 2006. 18 APPENDIX 19 APPENDIX A VICINITY MAP 20 APPENDIX B EXCERPTS FROM Filing 2 and 3 DRAINAGE REPORTS 21 APPENDIX C POND 306 VERIFICATION CALCULATIONS 22 APPENDIX D RATIONAL METHOD HYDROLOGY CALCULATIONS 23 APPENDIX E WEIR AND SWALE CALULATIONS 24 APPENDIX F LID RAIN GARDEN CALCULATIONS AND COMPLIANCE AND EROSION CONTROL ESCROW CALCULATIONS