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HomeMy WebLinkAboutDrainage Reports - 03/20/1998��rrwed Report final A 0ep,3j,4$ f - PROPERTY OF`. FORT COLLINS bins s FINAL DRAINAGE AND EROSION CONTROL REPORT FOR THE 2ND REPLAT OF SCENIC VIEWS PUD •r � ITMP ' CERTIFICATIONS OWNER C & A Construction, Inc. hereby certifies that the drainage facilities for the 2nd Replat of Scenic Views PUD shall be constructed according to the design presented in this report. I understand that the City of Fort Collins does not and will not assume liability for the drainage facilities designed and/or certified by my engineer. I understand that the City of Fort Collins reviews drainage plans pursuant to Colorado Revised Statutes Title 30, Article 28; but cannot, on behalf of C & A Construction, Inc., guarantee that final drainage design review will absolve the 2nd Replat of Scenic ' Views PUD and/or their successors and/or assigns of future liability for improper design. I further understand that approval of the Final Plat and/or Final Development Plan does not imply approval ' of my Engineer's drainage design. C & A Construction, Inc. /Xj / 1AA '46wner ' I hereby certify that this report for the Final Drainage and Erosion Control Report for the 2nd Replat ' of Scenic Views PUD was prepared by me or under my direct supervision in accordance with the provisions of the City of Fort Collins STORM DRAINAGE DESIGN CRITERIA and CONSTRUCTION STANDARDS for the owners thereof. I understand that the City of Fort Collins ' does not and will not assume liability for drainage facilities designed by others. Respectfully Submitted, 0 4-1• D. OR .G;s ' t M,Fo .`�Acok �,. :-- • 23830 ' Roger L. Mieden, P.E. %E'W�-, i 98Colorado Professional ENo2.18gL4,4 For and On Behalf of JR,,,�y\'� t t d 1 1 t [1 TABLE OF CONTENTS PAGE CERTIFICATIONS............................................................i TABLE OF CONTENTS....................................................... ii 1. INTRODUCTION....................................................... 4 1.1 Project Location...................................................4 1.2 Site Characteristics................................................. 4 1.3 Soils............................................................4 1.4 Purpose and Scope of Report .........................................5 1.5 Design Criteria....................................................5 1.6 Master Drainage Basin .............................................. 5 ' 2. HISTORIC (EXISTING) DRAINAGE ....................................... 6 1 1 1 3. DEVELOPED FLOWS ................................................... 7 3.1 Method..........................................................7 3.2 Exterior Flows....................................................7 3.3 Onsite Flows.....................................................7 3.4 General Flow Routing .............................................. 8 3.5 Proposed Drainage Plan .............................................8 3.6 Hydrologic Analysis of the Proposed Drainage Conditions ................ 10 3.7 Allowable Street Flow Capacities .................................... 11 3.8 Inlet Design.....................................................11 3.9 Storm Sewer Design..............................................12 4. RETENTION POND ..................................................... 13 5. SWMM Model.........................................................13 6. EROSION CONTROL .................................................. 14 6.1 Introduction.....................................................14 6.2 General Description ............................................... 15 6.3 Soil Description .................................................. 15 6.4 Erosion And Sediment Control Measures .............................. 15 6.5 Dust Abatement .................................................. 16 6.6 Tracking Mud on City Streets ....................................... 16 6.7 Maintenance..................................................... 16 6.8 Permanent Stabilization ............................................ 17 ii --------------- — --------- ... ... . ------------ 7. MISCELLANEOUS ....................................................17 7.1 Variances .......................................................17 7.2 Irrigation Ditches ................................................. 17 7.3 Ditch Company Approval .......................................... 17 7.4 Maintenance Agreements ........................................... 18 8. REFERENCES ........................................................19 APPENDIX A - MAPS AND FIGURES Al APPENDIX B - HYDROLOGIC CALCULATIONS BI-B5 APPENDIX C - INLET CALCULATIONS/OVERLAND TRAIL CAPACITY CALCULATIONS CI-C8 APPENDIX D - PIPE CALCULATIONS DI-DIO APPENDIX E - SWALE/CHANNEL CALCULATIONS EI-E6 APPENDIX F - SWMM RESULTS F I -F47 APPENDIX G - EROSION CONTROL GI-G6 APPENDIX H - EASEMENTS HI APPENDIX I - DITCH COMPANY AGREEMENT 11-14 APPENDIX J - RETENTION POND ELEVATION -STORAGE DURATION CURVES JI-J5 WATER QUALITY VOLUME APPENDIX K - STORMWATER QUALITY AND MANAGEMENT KI-KI7 CONTROL PLAN (PREPARED BY ROCKY MOUNTAIN RESEARCH INSTITUTE) 11 1 11 1 1, 1. INTRODUCTION 1.1 Project Location The 2nd Replat of Scenic Views PUD is a proposed 21.1 acre multi -family development located in the Northwest One -Quarter of Section 16, Township 7 North, Range 69 West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. (See FIGURE 1 - VICINITY MAP.) This project is bounded on the south by West Elizabeth Street, on the west by Overland Trail, on the north by undeveloped property, and on the east by undeveloped property and the Pleasant Valley and Lake (PV&L) Canal. More specifically, this site can be found in the northeast comer of the intersection of West Elizabeth Street and Overland Trail. 1.2 Site Characteristics The general topography of this site consists primarily of existing pasture land. The PV&L Canal traverses the site from northwest to southeast. The slopes range from 0.8 to 50 percent. The steeper slopes are found along the PV&L Canal. 1.3 Soils The soils for this site are comprised of the Altvan-Satanta loams (3) and (4), Loveland clay loam (64) and Satanta loam (95). (See FIGURE 2 - SOIL MAP.) The Altvan-Satanta loams (3) complex consists of nearly level soils on terraces and high benches. It is about 45 percent Altvan loam and about 30 percent Satanta loam. Pertinent characteristics of this soil include slow to medium runoff and a slight to moderate hazard of wind and water erosion. Altvan and Satanta loams are categorized in Hydrologic Group B. The Altvan-Satanta loams (4) complex consists of gently sloping or strongly sloping soils on high terraces, beaches, and fans. It is about 55 percent Altvan loam and about 35 percent Satanta loam. Pertinent characteristics of this soil include medium to rapid runoff and a ' moderate hazard of wind and water erosion. Altvan and Satanta loams are categorized in Hydrologic Group B. 1 4 11 1 1 1 1 Loveland clay loam (64) is a level soil that is on low terraces and flood plains. Pertinent characteristics of this soil include slow runoff and a slight hazard of water erosion. Loveland clay loam is categorized in Hydrologic Group C. Satanta loam (95) is a nearly level soil that is on terraces and uplands. Pertinent characteristics of this soil include slight runoff and a moderate hazard of erosion. Satanta loam is categorized in Hydrologic Group B. The source for soil data is the "Soil Survey for Larimer County Area, Colorado", prepared by the United States Department of Agriculture Soil Conservation Service. 1.4 Purpose and Scope of Report This report defines the proposed final drainage and erosion control plan for the 2nd Replat of Scenic Views PUD, including consideration of all on -site and tributary off -site runoff. 1.5 Design Criteria This report was prepared to meet or exceed the submittal requirements established in the City of Fort Collins' "Storm Drainage Design Criteria and Construction Standards" (SDDCCS), dated May 1984. Runoff computations were prepared for the 2-year minor and 100-year major storm frequency utilizing the rational method. Where applicable, the criteria established in the "Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver Regional Council of Governments, has been utilized. 1.6 Master Drainage Basin This site falls within the West Plum Street Basin and a report entitled "West Plum Street Basin Master Drainage Plan" prepared by Resource Consultants, Inc. October 29, 1990. This site was also included in a report entitled "Update of Hydrologic Analysis for West Plum Street Basin", prepared for the City of Fort Collins' Stormwater Utility by Ayres R 11 Associates, April 16, 1996. This report provides an analysis of the drainage patterns for this ' area under developed conditions, including the detention pond proposed as part of the previously approved Scenic Views PUD development. Note: This report was only an analysis and did not propose recommendations for future improvements. Information for this report was also gathered from the following: 1 I. "Preliminary Drainage Report for Scenic Views P.U.D.", prepared by Northern Engineering Services, Inc., February 20, 1996. ' 2. "Hydrologic Investigations for Scenic Views P.U.D. Subdivision", prepared by James H. Stewart and Associates, Inc., February 2, 1981. The overall drainage plan for the 2nd Replat of Scenic Views PUD is in compliance with the requirements of the reports listed above. ' 2. HISTORIC (EXISTING) DRAINAGE Historically, flows enter this site from the north and west. The two (2) general locations are as follows: 1. From the CSU Equine Center on the west side of Overland Trail ' The flows from this area enter the site in an existing 21 inch diameter RCP pipe under Overland Trail. 2. From the area to the north of this site. ' The flows from this area enter this site in sheet flow. Based on discussions with the City of Fort Collins' Stormwater Utility, the runoff from this site to be considered for sizing the proposed retention pond will be the 2-year historic flows. (The runoff ' in excess of this amount will be allowed to overtop the pond for now. At the time this property is developed, the additional flows will need to be detained and released 0 11 I into the proposed Scenic Views Retention Pond at a rate equal to or less than the 2- year historic rate.) ' Historically, flows leave this site to the east and into the PV&L Canal. The flows from the portion of the site east of the PV&L Canal leave the site and enter an existing downstream channel to the east of subject site. ' 3. DEVELOPED FLOWS 3.1 Method The Rational Method was used to determine both the 2-year and 100-year flows for the sub - basins indicated in this drainage report. A detailed description of the hydrologic analysis is ' provided in Section 3.6 of this report. The historic flows for this site are included as part of this report. The resulting 2- and 100- ' year runoff values were used to compute discharges at specific design points. ' 3.2 Exterior Flows Exterior flows enter this site from the west and north. All lands lying within these areas have been assigned land use characteristics reflecting their developed conditions as agreed to with the City of Fort Collins' Stormwater Utility. These areas areddentified on the attached "Drainage Plan" and calculations are included in the Appendix of this report. 3.3 Onsite Flows ' Flows within this site will take the form of overlot, swale, and gutter flow. The existing drainage patterns have been maintained where possible. All grading has been designed to ' carry flows away from structures to the proposed drainage facilities. 1 1 7 P ' 3.4 General Flow Routing The final drainage pattern for this area has been developed to provide a drainage system that is compatible with the surrounding area. This has been accomplished by utilizing existing drainage patterns to the extent possible and routing flows to limit the amount of required drainage facilities. The proposed drainage facilities for this site consist of proposed swales, inlets, underground Istorm sewer systems, and a proposed retention pond. (See below for further discussion.) ' The proposed drainage system meets the requirements for providing drainage relief by reducing the impact of the flows generated by the re -development of portions of this site on downstream areas (restricting release rates to existing) and meets the criteria in the SDDCCS. (See attached "Drainage Plan" for the location of all drainage facilities.) 3.5 Proposed Drainage Plan ' A qualitative summarization of the drainage patterns within each sub -basin and at each design point is provided in the following discussion paragraphs. Discussions of the detailed ' design of drainage facilities identified in this section are included in Sections 3.7. ' Runoff from Subbasin A is comprised of a small portion the southeast corner of subject site and a small portion of West Elizabeth Street. The flows from this area are carried easterly in gutter flow on West Elizabeth Street to the east boundary of ' subject site and released into the existing borrow ditch at Design Point 1 (as shown in the Preliminary Drainage Report for this site). (Note: This area is significantly smaller than the existing portion of West Elizabeth Street that contributes into said ' borrow ditch.) Runoff from Subbasin B is conveyed to the proposed internal street system and ' conveyed to a proposed sump condition inlet in the southeast portion of this site at Design Point 2. Said inlet outfalls into the proposed retention pond via a proposed underground storm sewer system. ' The runoff from Subbasin EXl (an existing residence) is routed onto Subbasin C ' via overland flow. 1 8 _1 1 Runoff from Subbasin C is conveyed to the proposed internal street system and conveyed to a proposed sump condition inlet in the east central portion of this site at Design Point 3. Said inlet outfalls into the proposed retention pond via a proposed ' underground storm sewer system. The runoff from the combination of Subbasins EXl and C is routed to the proposed sump condition inlet at Design Point 3. as stated in the previous paragraphs. Runoff from Subbasin EX2 (Overland Trail) is conveyed to Overland Trail, diverted northerly and southerly and carried to a proposed sump inlet at the location of the existing crossing under said Overland Trail at Design Point 4 (approximately the extension of the north boundary of this site). Runoff from D is internal Subbasin conveyed to the proposed street system and conveyed to a proposed sump condition inlet in the northeast portion of this site at Design Point 5. Said inlet outfalls into the proposed retention pond via a proposed underground storm sewer system. ' Runoff from Subbasin EX3 (from the off -site area.to the north) is conveyed onto ' Subbasin D via overland flow. Runoff from Subbasin E (the area east of the PV&L Canal where the proposed retention pond is located) is conveyed to the proposed retention pond. Runoff from Subbasins Fl is conveyed easterly via overland flow to the existing property to the east. Note: This area is significantly smaller than the historic area that flows onto the undeveloped property to the east (across the PV&L Canal). The 100- year developed discharge from Subbasin F1 is 9.3 cfs compared to the 100-year ' historic discharge of 33.6 cfs tributary to the canal for historic conditions. ' Runoff from Subbasins F2 is conveyed to a proposed inlet along the northern property line and discharges to the proposed retention pond. 1 1 9 I 1 I E 3.6 Hydrologic Analysis of the Proposed Drainage Conditions The Rational Method was used to determine both 2-year and 100-year peak runoff values for each Subbasin. Runoff coefficients were assigned utilizing Table 3-2 of the SDDCCS Manual. As stated above, the Rational Method was used for all hydrologic analyses for the project site. The Rational Method utilizes the SDDCCS equation: Q = CrCIA (1) where Q is the flow in cfs, A is the total area of the basin in acres, Cr is the storm frequency adjustment factor, C is the runoff coefficient, and I is the rainfall intensity in inches per hour. The frequency adjustment factor, C f, is 1.0 for the initial 2-year storm and 1.25 for the major 100-year storm. The appropriate rainfall intensity information was developed based on rainfall intensity duration curves in the SDDCCS Manual. In order to utilize the rainfall intensity curves, the time of concentration is required. The following equation was used to determine the time of concentration: t�=t;+t, (2) where t, is the time of concentration in minutes, t; is the initial or overland flow time in minutes, and t, is the travel time in the ditch, channel, or gutter, in minutes. The initial or overland flow time is calculated with the SDDCCS Manual equation: ti = [1.87(1.1- CCf)L"]/(S)' (3) where L is the length of overland flow in feet (limited to a maximum of 500 feet), S is the average slope of the basin in percent, and C and Cf are as defined previously. All hydrologic calculations associated with the sub -basins are attached in the Appendix of this report. Table 3.1 provides a summary of the design flows for all Subbasins and Design Points (DP's) associated with this site. Wi' [a I := DESIGN � � � r,TABI.,E AREA � X I)'I�I)�tAGl(1 AREA C2 �71t�1�IAit3� C100 Tc (2) TABU Tc (100) Q (2) YS Q (100) POINT DESIG. (ACRES) (MIN) (MIN) (CFS) (CFS) 1 fA 0.37 0.67 0.94 6.7 10.0 0.71 2.1 2 B 5.27 0.68 0.85 13.1 10.6 8.06 31.2 EX 1 1.06 0.21 0.26 11.6 11.6 0.54 1.9 8 C 8.19 0.67 0.84 5.7 10.0 16.66 48.7 3 EXI,C 9.25 0.62 0.78 17.3 16.3 11.25 40.9 EX1,B,C 14.52 0.64 0.80 17.3 16.3 18.34 66.7 5 D 3.03 0.59 0.74 10.6 10.0 4.38 15.8 4 EX2 1.32 0.69 0.86 6.9 10.0 2.62 8.1 6 EX2,D 4.351 0.62 0.78 16.91 10.0 5.38 24.0 E 2.93 0.20 0.25 11.7 11.7 1.38 4.9 7 EXI,EX2, 21.80 0.58 0.73 17.3 16.3 24.81 90.3 B,C,D,E F 3.50 0.39 0.49 11.2 11.2 3.27 I1.5 EX3 6.50 0.20 0.25 12.8 12.8 2.95 10.4 9 F1,EX2, PORTION EX3 4.08 0.44 0.55 21.0 19.0 3.23 12.1 ' 3.7 Allowable Street Flow Capacities ' The 2nd Replat of Scenic Views PUD has only a minor impact on flows from the surrounding existing streets. Therefore, calculations for allowable street capacities are not included for interior streets. Calculations for Overland Trail are included in Appendix C, Pages C6-C8. 3.8 Inlet Design There are four (4) Type "R" sump condition inlets and one (1) area inlet proposed with the 2nd Replat of Scenic Views PUD. One of the sump inlets is located on Overland Trail and ' the other three (3) are located in the roadways in the southwest portion of this site. The area inlet is located in the north central portion of this site at a junction in the proposed CSU Equestrian Center outfall storm sewer. (See Appendix for Calculations.) 11 I3.9 Storm Sewer Design ' There are two (2) underground storm sewer pipe systems proposed with the development of the 2nd Replat of Scenic Views PUD. These two systems are as follows: 1) the extension of the existing culvert under Overland Trail from the CSU Equestrian Center through a proposed sump condition inlet and into the proposed retention pond; and 2) the outfall storm sewer system from the southerly and central portions of this site. CSU Equestrian Center Outfall Storm Sewer This underground storm sewer system has been designed to carry, the existing flows from said existing culvert and the three proposed inlets to the proposed retention ' pond, and includes a crossing under the PV&L Canal. (See Table 3.2 below. See Appendix for calculations.) Outfall Storm System - Southerly and Central Portions of Site This underground storm sewer system has been designed to carry the 100-year ' developed flows from the southerly and central portion of this site to the proposed retention pond. (See Table 3.2 below. See Appendix for calculations.) PIPE DESIGN REACH DESCRIPTION SIZE DISCHARGE (inches) (cfs) From Design Point 4 Inlet (Overland Trail) to Design Point 5 1 Pipe 21" 25.0 From Design Point 5 Inlet to Retention Pond ' Outfall Pipe 29" X 45" 43.0 From Design Point 2 Inlet to Design Point 3 Inlet ' Pipe 24" X 38" 31.3 From Design Point 3 Inlet to Retention Pond ' Outfall Pipe 42" 66.8 �I 12 4. RETENTION POND There is one retention pond proposed with the development of the 2nd Replat of Scenic Views PUD. This pond is located in the northeast comer of this site. This retention pond has been designed to retain two times the 100-year developed runoff from the Scenic Views site. Stormwater runoff which collects in the retention pond will be discharged to the Pleasant Valley and Lake Canal by a pumping station located between the retention pond and the canal. A water quality inlet consisting of a perforated riser pipe with a gravel filter is ' provided within the retention pond which drains to the pump station. The water quality inlet and the water quality volume provided in the pond are designed to drain the water quality volume within 40 hours, which corresponds to a pumping rate of 70 gpm. For larger storms, a 500 gpm pump is available which will also discharge to the canal. The larger pump is intended to be started manually about 24 hours after a large storm and will turn off automatically when the water level reaches the top of the water quality volume. The smaller ' pump will turn on and off automatically to drain the water quality volume in a period of 40 hours. An emergency overflow weir is provided at the east side of the pond to convey flows in excess of the design flows. This concept was determined as the result of discussions ' between Bill Veio of Solitaire Properties, LLC, and Glen Schlueter of the City of Fort Collins Stormwater Utility.) (See Appendix J, pages Jl through J5 for calculations and ' Drainage Plan for additional information.) To control groundwater infiltration to the retention pond, a clay cutoff wall or slurrywall will be constructed around the perimeter of the retention pond. The cutoff wall will penetrate ' permeable layers of soil that convey groundwater above the - level of the bedrock and essentially isolate the retention pond area from the surrounding groundwater effects. Additional information regarding remedial measures for water quality enhancement are included in "Stormwater Quality and Management Control Plan" prepared by Rocky Mountain Research Institute (Reference 7, also included as Appendix K of this report). ' 5. SWMM Model The 2nd Replat of Scenic Views P.U.D. is located in the SW 1/4, NW 1/4, Section 16, Township 7N, Range 69W. This location represents Sub -basin I in the Hydrologic 13 I F, I I' Analysis For West Plum Street Basin. The developed site was modeled using SWMM. The site was modeled using an imperviousness of 60%. The 100-year storm was routed into the retention pond. It should be noted that Subbasin F is considered to drain to the east via overland flow into the PV&L Canal and, therefore, was not routed into the on -site retention pond. The West Plum Creek Drainage Basin SWMM model was modified to include the 2nd ' Replat of Scenic Views PUD in Subbasin 11 as well as modifying detention pond number 202 to represent the currently proposed retention pond. The entire updated model was run for the 100-year design storm for the West Plum Basin. The peak discharges for these runs are as follows: Design Exiting Scenic Exiting Scenic Master Plan Peak Storm View View Ret. Pond Flows (Conv. Element 59) (Conv. Element 202) (Conv. Element 202) 100-Year 145 cfs 0 cfs 89 cfs * From "Update of Hydrologic Analysis for West Plum Street Basin", Ayres Assoc. ' Note: The peak discharge values exiting the Scenic Views Retention Pond include the routing of Subbasins 10 and 12 from the West Plum Creek Basin. See Appendix for SWMM output data. ' 6. EROSION CONTROL ' 6.1 Introduction ' This section represents the Erosion Control Report for the 2nd Replat of Scenic Views PUD and was prepared to meet the regulatory requirements of the City of Fort Collins, Colorado. This report was prepared following the guidelines and regulations within the SDDCCS ' Manual. 14 6.2 General Description The total site is comprised of approximately 21.1 acres. The proposed improvements comprise the entire site. 1 The general topography of this site consists grass covered pasture type land. This area slopes 1 easterly at slopes ranging from 0.8 to 50 percent. The steeper slopes are found in the easterly portion of the site along the PV&L Canal. 6.3 Soil Description ' In accordance with the Soil Conservation Service's (SCS) "Soil Survey of Fort Collins Area, Colorado" (copy reproduced in Appendix), the soils on -site consist of the following: Rainfall Wind Hydrologic ' Soil Designation Erodibility Zone Erodibility Zone Soil Group Altvan-Satanta loams(3) Moderate Moderate B Altvan-Satanta loams(4) Moderate Moderate B ' Loveland clay loam Slight Slight C ' Satanta loam Moderate Moderate B ' (See Section 1.3 for further discussion of soils found on this site.) 6.4 Erosion And Sediment Control Measures Erosion and Sedimentation will be controlled on -site by the use of straw bale barriers, silt fence, inlet protection and gravel construction entrances. (See Appendix G, Page G6 for Cost Estimate). A gravel construction entrance will be located adjacent to Overland Trail, straw bale barriers will be placed along graded swales and silt fence will be placed along the downhill face of graded areas subject to erosion. Inlet protection will be placed around storm ' sewer inlets. Please refer to the "Drainage and Erosion Control Plan" for exact locations , construction details and construction sequence.) ' 15 1 The measures are designed to limit the overall sediment yield increase due to construction as required by the City of Fort Collins. A construction schedule is contained in Appendix G and shown on the "Drainage and Erosion Control Plan" which shows the overall time frame for construction activities. Silt fence will be utilized in limited areas adjacent to any stockpiles that are created during grading. Additional discussion of erosion control measures is included in "Stormwater Quality and Management Control Plan" (Reference 7). ' 6.5 Dust Abatement ' During the performance of the work required by these specifications or any operations appurtenant thereto, whether on right-of-way provided by the City or elsewhere, the contractor shall furnish all labor, equipment, materials, and means required. The Contractor shall carry out proper efficient measures wherever and as necessary to reduce dust nuisance, ' and to prevent dust nuisance, and to prevent dust which has originated from his operations from damaging crops, orchards, cultivated fields, and dwellings, or causing a nuisance to persons. The Contractor will be held liable for any damage resulting from dust originating ' from his operations under these specifications on right-of-way or elsewhere. ' 6.6 Tracking Mud on City Streets ' It is unlawful to track or cause to be tracked mud or other debris onto city streets or rights -of - way unless so ordered by the Director of Engineering in writing. Wherever construction vehicles access routes or intersect paved public roads, provisions must be made to minimize ' the transport of sediment (mud) by runoff or vehicles tracking onto the paved surface. Stabilized construction entrances are required per the detail shown on the Plan, with base ' material consisting of 6" coarse aggregate. The contractor will be responsible for clearing mud tracked onto city streets on a daily basis. ' 6.7 Maintenance All temporary and permanent erosion and sediment control practices must be maintained and repaired as needed to assure continued performance of their intended function. Straw bale ' dikes will require periodic replacement. Sediment traps (behind hay bale barriers) shall be cleaned when accumulated sediments equal about one-half of trap storage capacity. 1 16 I I 1 7. Maintenance is the responsibility of the developer. 6.8 Permanent Stabilization A vegetative cover shall be established within one and one-half years on disturbed areas and soil stockpiles not otherwise permanently stabilized. Vegetation shall not be considered established until a ground cover is achieved which is demonstrated to be mature enough to control soil erosion to the satisfaction of the City Inspector and to survive severe weather conditions. MISCELLANEOUS 7.1 Variances There are no variances requested with the development of the 2nd Replat of Scenic Views PUD. 7.2 Irrigation Ditches The development of the 2nd Replat of Scenic Views PUD does not adversely affect the PV&L Canal as the flows directed to it are less than historic (only the portion of the site ' immediately west of said canal). A profile of the downhill bank of the irrigation ditch is shown on the drainage plan with two locations noted as "Probable Overflow Location". These are based on the low points of the existing berm and represent where overflow could ' occur during a severe storm if the ditch capacity is exceeded due to conveyance of stormwater. It should be noted that overflow may not occur if the capacity of the ditch ' further upstream is less (overflows would occur finther upstream) or the amount of stormwater conveyed is not significant with respect to ditch capacity. No grading is proposed in the immediate vicinity of the overflow locations that would reduce the capacity of any overflow section. ' 7.3 Ditch Company Approval ' An agreement was signed by the Ditch Company and Owners of the 2nd Replat of Scenic Views PUD in 1981 when this site was originally approved. Said agreement applies to the ' 17 t ' original owner's of this property as well as their successors. The current Developer of this site has been in contact with the Ditch Company. A signature block has been added to all ' applicable utility plans for Ditch Company approval. (A copy of said agreement is included in the Appendix.) 7.4 Maintenance Agreements ' The developer will be responsible for the maintenance of all temporary drainage structures. 1 [] 11 1 1 1 18 8. REFERENCES 1. "Preliminary Drainage for Scenic Views P.U.D.", prepared by Northern Engineering Services, Inc., February 20, 1996. 2. "Hydrologic Investigations for Scenic Views P.U.D. Subdivision", prepared by James H. Stewart and Associates, Inc., February 2, 1981. 3. "Update of Hydrologic Analysis for West Plum Street Basin", prepared by Ayres Associates, Revised April 16, 1996. 4. City of Fort Collins, "Storm Drainage Design Criteria and Construction Standards", (SDDCCS), dated May, 1984. 5. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria Manual", Volumes I and 2, dated March, 1969, and Volume 3 dated September, 1992. 91 7 "Spring Creek Master Drainageway", prepared by Engineering Professionals, Inc., dated March, 1988. "Stormwater Quality and Management Control Plan", prepared by Rocky Mountain Research Institute, February 1997. I] I 1 1 APPENDIX A MAPS AND FIGURES 1 At I 1 I I I I I 1 1 LA PORTE _J z W MULBERRY O - x SITE w EuzA ETH � W PROSPECT VICINITY MAP 1 " - 2000' I I I 1 1 1 APPENDIX B HYDROLOGIC CALCULATIONS I ajo Z W Vl W W O o N W 0 O N 1 LL trp C w = S Z OJ J w Q W O ZO O 0 N O) 0 f D o O J J Q a U c7 N U Z /w W � N z U Q (� Z G_ Z lu 2 W CO U Q n U ~ W b l N N M m N of N l^O 100 N a j o 0 C 0 0 C 0 0 o Q 0 0 O U QLL O O O O O O O O C+ O Z UJ N Cl! N N N N N N Q O O C G G O G G C Q O � U w N Ill O tJ C fV N O < z LL LL Q LL W Zo ONl ONI A T A ONi OOi W ONI W C o 0 0 o C o a opo � U Q O O O O aN0 V O O Q N LL' O O O O O O O O Q m LL LL Q LL W � 0A N ONI A ONI Z D o C 0 a a C C o o C O o a: U Y Nr J Q Q � to O � � yy W 0 C N O l7 aD O O O C O l7 O O Q 0 J 4 W tr�f N O O M O�1 m tN0 N o Q O N m CI fV N C . {n fG O V+ QQ co IX U O x W LL LL X IL 0){11 , W Q r N I I r J ' m m N N ' O A m m N ' 0 0 1 ' Z N LL. �3 N 0 1'- f J LL ' O LL W 0 Z0. 0 O O Z Ci W ' y 0 W Wp 1 ' J O a z I^ o m N � � W a o S z p` U 0 U aas W W W IL m v o rn p m O 2 z m w E9�N c9 a � O W O J �N p J O U al Ym LL. n K � 2 f Z u y LL r m m m m n N m p O Ip N CI t7 tV 4 + y � m 11 J Q Z J W = Q (0 C N N m m m m N m U � f n a n m m m m E N N U y � N N N m(+1 (7 _ - O I'l N y n m N N CI fV (V n � m m m m o � m N ... W f= IJu > c a n o o m o 0 V N Ol m m O m m ! m m m C! n Cl O l7 �p l E � 1 0 o r o n o r a o q o N fV CI N Ol CI lV lV l7 y" r > m m N m YO! J« U G G G C C C C C O \\r F W — m N O O M A N m W miH O N aD Vl H Q V z F S2 _z ITil lo W o O a z m¢ G m H m c� o Is W LL v M °N z m X N � K. w � ¢ z E o m m o 0 o r N m J O O O O O lV _ P LL O O m N N N N + i u O y ] H N m n r Q m m n r p Q O m Y m Yl pi N E u 0 U N m N O OI o = E N P n 1 m N N CI CI N m m w m o� lcql o t. WJ P C n O Yl m m J v KQ F z' Q m 0 YI OI C > E m N J 0 o n o n o n m m qg p � m CI lV Cl N m CI M CI f c = a v 1 J m m N 0 0 r o m c N o O 0 0 0 _ = F tn�l N m O W O N N N 1 m (j z �_ O H I w i O z � m U U 161 m�a C m ex� x y r-:- N 0 O 6 I N f J° I Q J � Q Q U � m t0 N vi /\ I to `v w X = W O W � � O W U K f O a n O � WE = W a i 23 O 00 0 0 ' N ` ' N h 0 O U > w a > O Z U w Y W ' W r 5 LL N N m C J 0 m y � Z > U 0 O m �s CO) 0w0m WN v O0 N EIIIIIIIIIIIIIIIIIIIIIIIIIIII ■I�I�I�IBI�1�1�1�1�1�1�11�1�1 i191�1�161@I�1�1@I�1�1�11�1�1 ■1@I�1@I�1�1�1�1� �1@I�11�1� ■1�1�1�1�1�1�1�1���1�1�11� �� ■1�1@I@I�1@IBI�1@I�1�1�11��@I ■1@I�1�1@I�1�1�1�1@I�1�11�1@I . 81-i 7 _ QT ,N a -Il i 0 V m ` N � � N V m � O l� ✓ J e N m W ii I I I � � (/§ •2■ �|k J� � .— I �/ )\ j §§wz ` ga � 0 § '1 (Y �} & .. 00w 7 7@� �0 k�(k S§S2 �■ \ CO) wco L L ; { ki 7 o \ � { ------------------------- lz a { `Cd } 4® ` \ q / / § § § § § § § 1-1 1-1 m § § § § 2 7 C4$ --------------------- C41 Iƒ j : \ $2 ƒ LLI i « 5 0 } \ E } § & �] IK 82 ' FM \LP- � & / 3 5 ° \ } \ \ \ ) \ � � \ > \ m \ < & / \ § �� e m ( � / [ \\ \\ \ t� ( JR Engineering, Ltd. "'E,,. Rm,e i �9�{ y��"� JOB NO. MJECT sLLaJ'C-'�6 V, Lam-+ P'j i� . .BY�B�Y DATE tD Z/ /9% SUBJECT lW1,5 j • /yy' " — /Qd k-/ 7-, SHEET NO. _ OF _ ,A (,E .7a9�0.l0;.3 AL, __ r _4- era ZT QLL 1 1 f i- I PndrJo r's+�a SPA C I _ _Sew Mti 'srz� t 3 12 1 1 1 1 1 Engineering, neering, Ltd. ` , RA4 P2 ,OH Na FRwEcr ��), ll,e] P,IJQ,J7, BY ��►') B uve z, 9-7 SUWECr l -DES. / — "IC)9� V cu-)&L- •% MMU Na _ OF _ iz i 1 0.b31.`51, + Z,13 . Z-► � z,13(,3L4 =,55 EX 3) L/Y ��. g� � �V,. 08) = .3. Z 3 c �- s i ._mil I 1 t 1 i .. - . � I.A. � • - . i -.u'•�_ J-4. l J LJ� No Text 1 I 1 1 APPENDIX C INLET CALCULATIONS ' OVERLAND TRAIL STREET CAPACITY CALCULATIONS 1 1 1 1 1 C/ SCENIC VIEWS PUD ' 06/25/96 ' SUMP CONDITION INLETS @ DP 2 SOUTHEAST PORTION OF SITE FLOW ALLOWABLE FLOW DEPTH (Q) (Yo) (NOTES) Q2 = 8.06 CFS 2 YR = 0.50 FT. TOP OF CURB ' Q100 = 31.26 CFS 100 YR = 1.00 FT. 6" OVER CURB HEIGHT OF OPENING = H = 0.50 FT. 2 YEAR CALCULATIONS Yo/H = 1.00 FROM FIGURE 5-2 O/L = 0.93 CFS/FT ' INLET SIZE 12.00 FT. REDUCTION FACTOR = 0.85 ' Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 9.49 CFS O.K. 100 YEAR CALCULATIONS Yo/H = 2.00 FROM FIGURE 5-2 OIL = 2.40 CFS/FT 1 ST TRY INLET SIZE 16.00 FT. REDUCTION FACTOR = 0.90 ' Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 34.56 CFS O.K. OVER FLOW ' 2 YR 0.00 100 YR 0.00 CFS CFS ' INLET REQUIRED IS COOT TYPE "R", LENGTH FEET @ DP 2 1 X:19W200\QPW%S_INLET.NB20627/9614:01:59 PAGE 1 OF 4 SUMP INLETS cz ' @ DP 3 EAST CENTRAL PORTION OF SITE FLOW ALLOWABLE FLOW DEPTH (Q) (YO) (NOTES) Q2 = 11.25 CFS 2 YR = 0.50 FT. TOP OF CURB Q100 = 40.94 CFS 100 YR = 1.00 FT. 6" OVER CURB ' HEIGHT OF OPENING = H = 0.50 FT. 2 YEAR CALCULATIONS Yo/H = 1.00 FROM FIGURE 5-2 Q/L = 0.93 CFS/FT tINLET SIZE 14.00 FT. REDUCTION FACTOR = 0.90 Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 11.72 CFS O.K. ' 100 YEAR CALCULATIONS Yo/H = 2.00 FROM FIGURE 5-2 Q/L = 2.40 CFS/FT 1 ST TRY ' INLET SIZE 20.00 FT. REDUCTION FACTOR = 0.90 Q = (Q/L)X(REDUCTION FACTOR)X(I N LET SIZE) = 43.20 CFS OX ' OVERFLOW 2 YR 0.00 CFS 100 YR 0.00 CFS ' INLET REQUIRED IS CDOT TYPE "R", LENGTH = 20 FEET @ DP 3 1 1 ' ' X:%9062001QPWtS_INLET.WB206/27/9614:02:00 PAGE 2 OF 4 - SUMP INLETS C3 @ DP 4 OVERLAND TRAIL FLOW ALLOWABLE FLOW DEPTH (Q) (Yo) (NOTES) Q2 = 2.62 CFS 2 YR = 0.50 FT. TO TOP OF CURB (1/2 ST ' Q100 = 8.16 CFS 100 YR = 1.00 FT. TO ROW HEIGHT OF OPENING = H = 0.50 FT. 2 YEAR CALCULATIONS Yo/H = 1.00 FROM FIGURE 5-2 Q/L = 0.93 CFS/FT ' INLET SIZE 4.00 FT. REDUCTION FACTOR = 0.80 ' Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 2.98 100 YEAR CALCULATIONS CFS OX Yo/H = 2.00 FROM FIGURE 5-2 Q/L = 2.40 CFS/FT 1 ST TRY INLET SIZE 5.00 FT. REDUCTION FACTOR = 0.80 Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 9.60 CFS O.K. INTO SWALE 2 YR 0.00 CFS 100 YR 0.00 CFS INLET REQUIRED IS CDOT TYPE "R", LENGTH = FEET @ DP 4 1 1 1 , X:%082001OPWkS_INLET.WB20627/9614:02:00 PAGE/OF4 SUMP INLETS - 1 Cq ' @ DP 5 NORTHEAST PORTION OF SITE FLOW ALLOWABLE FLOW DEPTH (Q) (YO) (NOTES) Q2 = 4.38 CFS 2 YR = 0.50 FT. TOP OF CURB Q100 = 15.87 CFS 100 YR = 1.00 FT. 6" OVER CURB tHEIGHT OF OPENING = H = 0.50 FT. ' 2 YEAR CALCULATIONS Yo/H = 1.00 FROM FIGURE 5-2 Q/L = 0.93 CFS/FT ' INLET SIZE 6.00 FT. REDUCTION FACTOR = 0.80 Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 4.46 CFS O.K. ' 100 YEAR CALCULATION Yo/H = 2.00 FROM FIGURE 5-2 Q/L = 2.40 CFS/FT 1 ST TRY INLET SIZE 8.00 FT. REDUCTION FACTOR = 0.85 Q = (Q/L)X(REDUCTION FACTOR)X(INLET SIZE) = 16.32 CFS O.K. fOVERFLOW - 2 YR 0.00 CFS - 100 YR 0.00 CFS ' INLET REQUIRED IS CDOT TYPE "R", LENGTH = B FEET @ DP 5 1 1 X:\908200\QPW%S_INLET.WB206/27/9614:02:00 PAGE�OF4 SUMP INLETS I cs 1 TD Engineering, Ltd. CLIENT RMZX JOBNO. 3(,71-,ob lJj�, PROJECTPU.J7, BY JR)") CHECK BY DATE FLIS177 1 SUBJECT /WA-(� D/ZAwiI46tr5 SHEET NO. OF 1 1 i 1 1 1 i 1 [1 I 1 1 1 1J 1 1 I � _ -�' /tDO`iJ ..1s7?�2 T_!=C co MI I a-- - j- Ill- i ( st LiT - f- ZYI 'I" o '-1-L - 7-5 -3-& ` t(as— C� JREngineering, Ltd.' / CLIENT �'� ��T JOB NO. PROJECT SCenny, L fwr BY_47m CHECKBY DATE J-4 I? —? ' SUBJECT &Jq` ��}�..i ,46E SHEET NO. OF [1 I 1 [1 i� E - 05,1- r OT — T- r, +_4._ SE _ tt- 4 ,_rvs i -. ' r �9 4).�l 7 j-L - A o I j 1 I z_� 1 J �31 Z'� S Y T :A t TZ in�[iJJTZ ILI & i ( U)`/ C7 ASPH•- 6000 7000 6000 5000 4000 ) IJ r — i .10 06 % ES4u•lE .it Hw• u.u• .05 wo a..a.• • • ..» \3000 re • <• 07LL- </n re• to .04 2000 eo ...•.. .. of 2.0 X-11 e0 70 60 .50 IL 40 2 1000 Z 30 900 800 `• z �- 700 � 1 CY Soo Nz 300o z 1 400 w = INSTRUCTIONS U. J of Q 300 or w �. • <HNcr IJn u.K «.. Iaen m Q a! Z 1.007 ..e .it, m.c.... I m ..•- = el Z .008 200 sa••. rn .N(< .N \..<• ..•. v e= Q <e.n(•t .aa.••H of U .006 t.IH P.aaM LL .0OS 100 ...•.n• c....f\ 090 If M....•1 NN..... so --I. _ .004 70 r w 6c 0- O 30 1 .• of •I....a _ .003 wu.o.a •� s N 40 30 1.1 From BP ee u.w.a fa••. J .H •ena •.f<-.•o .. .002 rI I•I N.•V J: ••.u. • rH Fgure 4-1 NONOGRAPH FOR FLOW IN TRIANGULAR GUTTERS (From U.S. Dept. of Commerce. Bureau of Public Roads, 1965) F .20 F- Z 9 F- En .10 w a- .08 w w .07 06 0.' 0 .OS m .04 U F 03 Q F .02 a w O Fr MAY 1984 4-3 DESIGN CRITERIA M M are .9 U 7 .3 .2 IS06 F-08 .f *0.4% F D 5 -T I BELOW ALLOWABLE STREET I MINIMUM GRADE I .0 0 2 4 6 a 10 12 la SLOPE OF GUTTER M) Figure 4-2 REDUCTION FACTOR FOR ALLOWABLE GUTTER CAPACITY Apply reduction factor for applicable slope to the theoretical gutter capacity to obtain allowable gutter capacity. (From: U.S. Dept. of Commerce. Bureau of Public Roads. 1965) MAY 1984 4-4 DESIGN CRITERIA I 1 APPENDIX D PIPE CALCULATIONS 1 ----------------- Discharge: 31.26 ischarge: 31.26 ischarge: 72.20 Discharge: 72.20 ischarge: 72.20 ischarge: 72.20 Calculation Cycle ------------------- INLET NO. 1 J-1 INLET NO. 2 J-2 J-3 Outlet eginning iteration 1 Discharge: 31.26 cfs at node INLET NO. 1 ischarge: 31.26 cfs at node J-1 ischarge: 72.20 cfs at node INLET NO. 2 Discharge: 72.20 cfs at node J-2 ischarge: 72.20 cfs at node J-3 ischarge: 72.20 cfs at node Outlet ischarge Convergence Achieved in 1 iterations: relative error: 0.0 ** Warning: Design constraints not met. information: Outlet Sump elevation must be at or below minimum invert levation of: Information: Outlet Known flow propogated from upstream junctions. information: P-5 Surcharged condition nformation: J-3 Known flow propogated from upstream junctions. nformation: P-4 Surcharged condition Information: J-2 Known flow propogated from upstream junctions. tnformation: P-3 Surcharged condition iolation: P-3 does not meet minimum slope constraint. Information: P-2 Surcharged condition information: J-1 Known flow propogated from upstream junctions. -nformation: P-1 Surcharged condition ----------------- Calculations Complete ---------------------- - Beginning cfs .at node cfs at node cfs at node cfs at node cfs at node cfs at node * Analysis Options ** riction method: Manning's Formula HGL Convergence. Test: 0.001000 aximum Network Traversals: 5 umber of Pipe Profile Steps: 5 ischarge Convergence Test: 0.001000 Maximum Design Passes: 3 ----------------- Network Quick View ' Label P-1 _2 -3 P-4 5 Length Size 41.44 24x38 inch 346.14 24x38 inch 95.38 42 inch 60.00 42 inch 220.84 42 inch Label rNLfiT NO. 1 INLET NO. 2 3 tlet Elapsed: 0 Discharge 31.26 31.26 72.20 72.20 72.20 Discharge I 2 Ground 31.26 19.00 31.26 18.99 72.20 17.92 72.20 17.00 72.20 19.00 72.20 4.00 minute(s) 34 second(s) Hydraulic Upstream 18.45 17.96 15.58 14.65 13.64 Grade Downstream 18.25 16.28 15.08 14.34 12.50 Elevations ---------------- Upstream HGL I Downstream HGL 18.45 18.45 18.25 17.96 16.28 15.58 15.08 14.65 14.34 13.64 12.50 12.50 D1 Project Engineer JR ENGINEERING, LTD. F/F3m 67600Worcad\908200b.stm n JR Engineering, LTD StonCAD v1.0 15/87 03:31:48 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 N 0 m d d O Z W Z a U C E x 0 0 0 N m O spa Fu N C � p 0 0 o n� n k o ` ii I 1 1 I I I c 0 n U 0 O m W t7 O Nl C N O O O yp 2 0 0 0 0 Q O U E o N o m o N O m N 0 N j N C O > � O w O E quo vnHmm v>> � W O O O p m m �O Q> � OI m m t7 M CU ... t7 N O O N N C V U od < r r r � o xx�.� O O N N N N N V O < d o Q o Q a Q'_ ozozzz W N N gNt 0 0 0 0 0 0 o 0 0 0 0 FVm Qadaa Q Q N c U u O O Q a z o Z Z _ m O Q O Q Q a W N c LO O 0 O Z a z z 10 O M O Ole+ n J�' V V Of tOp N NN LD m z Z FN 3 Z _ W N J N h OO z > > 0 � N Lo Z Z nZ W W Z Z N 6 N l7 q m IL drLdad -7J 3 oa� J j O ZUW woa z w m 0 z w a E 4- ---------------- Beginning Calculation Cycle ------------------- �Y Discharge: 25.00 cfs at node INLET NO. 3 ischarge: 25.00 cfs at node J-1 ischarge:'43.03 cfs at node INLET NO. 4 Discharge: 43.03 cfs at node J-2 ischarge: 43.03 cfs at node J-4 ischarge: 43.03 cfs at node Outlet eginning iteration 1 Discharge: 25.00 cfs at node INLET NO. 3 ischarge: 25.00 cfs at node J-1 ischarge: 43.03 cfs at node INLET NO. 4 Discharge: 43.03 cfe at node J-2 ischarge: 43.03 cfs at node J-4 ischarge: 43.03 cfs at node Outlet ischarge Convergence Achieved in 1 iterations: relative error: 0.0 ** Warning: Design constraints not met. arning: No Duration data exists in IDF Table nformation: Outlet Known flow propogated from upstream junctions. Information: P-5 Surcharged condition Violation: P-5 does not meet minimum cover constraint at downstream end. information: J-4 Known flow propogated from upstream junctions. nformation: P-4 Surcharged condition Information: J-2 Known flow propogated from upstream junctions. nformation: P-3 Surcharged condition iolation: P-3 does not meet minimum slope constraint. Information: P-2 Surcharged condition Violation: P-2 does not meet minimum slope constraint. information: J-1 Known flow propogated from upstream junctions. nformation: P-1 Surcharged condition --------------------- Calculations Complete ---------------------- t* Analysis Options ** Friction method: Manning's Formula ,FGL Convergence Test: 0.001000 aximum Network Traversals: 5 umber of Pipe Profile Steps: 5 Discharge Convergence Test: 0.001000 raximum Design Passes: 3 ----------------- Network Quick View Label 1 -2 P-3 14 _5 tLabel NLET NO J-1 NLET NO -2 utlet J-4 lapsed: Length Size 297.64 21 inch 107.16 30 inch 50.91 29x45 inch 29.99 29x45 inch 61.47 29x45 inch Discharge 3 25.00 25.00 14 43.03 43.03 43.03 43.03 0 minute(s) 34 Ground Discharge 25.00 25.00 43.03 43.03 43.03 23.50 15.00 17.67 17.00 1.00 14.07 second(s) Hydraulic upstream 22.22 14.49 13.67 13.07 12.71 Grade Downstream 14.81 14.09 13.50 12.97 12.50 Elevations ---------------- Upstream HGL I Downstream HGL 22.22 22.22 14.81 14.49 14.09 13.67 13.50 13.07 12.50 12.50 12.97 12.71 Project Title: SCENIC VIEWS PUD Project Engineer: JR ENGINEERING, LTD. \967600\stonncad\9082csu3.stm JR Engineering, LTD StonnCAD v1.0 /16/97 04:26:55 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 cl IL U) W U_ Z 0 U) �s- om J j O Z Q 01 C �Ea O wo n Z h C w +J 0 w d c a 0 W N � LO I.L 0 a` i n m n LL. m r N 0 � � m a r Z co 0 Cn U ? \LLI J ui a t5 J N — (6 m 3 U Eo W o d' N o Z m N a � l`J m O N � Z W J Z E ai a q Wo W N TT 1 O a V v C v zmo fR �V U N co L. NE o mho F o r � m rn m�N 0 axo I 1 I 1 1 I 1 c 0 n U 0 N UO N p YI N N N t N q O < �C h a O A .OIv N O N N N N N N c w w 00 V q N U ty0 U (p U OLN NN q L N L O C O C 0 C U U O N O N O Yl U U S X K N K O O O U N U� S ry 2 N 2 N C p�L` o' 0 0 m 0 m o m N O 0 0 0 0O f� O N O O L G N y AUv N U O W?r 0 0 0 0 0 0 0 0 0 0 O U E N Q O N O W E a0 0 h O d N N J (_� N a C N -- -^ - - ^- E o 0 0 0 n 0 o n o 0o000000 00 C N W N .-. O N A a N O O O O O o 0 0 0 0 F U m Q O a a N N Q N O O Z O Z Z cUu o a g a a Z o Z Z E m e a z z z n; w w w N J J J N N g q 0 QO n `a N m v N d d d a d m b N r O N c E a �? N m 3' W_ N Moog vO�a to U € ai N O- bi F O n $ n , m m h o�_ d x o I WA LJ I I I I I i �' fIA I I I I I I I c 0 n U 0 0 0) V N O m N O O O r Oaf 0 0 0 0 0 cN� o 0 0 0 0 O U E 0 0 0 n o o rn o n o O C y W 0 o p�f0i �>c ai o o ai > N QCy � W La Q Z• O N0 N N m m N t7 N 0 .... N U L L L C O i oui .v x rn rn N th N N N y O O z O z z s 0 0 0 0 0 �Qw o000 FUW dd6dd a a 0 mQ O 0 o z o z z cU� ogoa__Q 2U ozozz a O N O z 0 o o Z Z C� U v 5 �0 rnr- O) O) IT 0J n n O O `-' N O N N N E 10 O �v z E0 O 3 z W 0 ' J Z N q = 0 in v 9c z z DZ J J N 6 'a �- N 7 v N d d a a d j j O wEa w E zw w 0 z w rc a F U j E a H fn M W N 50 UO2 W U O y€ al O � myo Fon O m N OC1 � a w 0 I /: I ' Structure Headloss I- TiD ' StormCAD allows you to specify structure headloss for the node element as an absolute value, or calculate headloss using the Standard method. ' Note: The velocity reported under the Structure Headloss group is the exit velocity from the structure. (The velocity used in the Standard Method equation.) I C� 1 1 I I 1 I -D9 I ' Headloss Coefficient - Standard Method ►lip The Standard Method estimates headloss through inlets or manholes of a storm sewer system. The equation for estimating headloss is: ' hL -K2 2 9 Notation K Headloss coefficient V Velocity leaving structure g Gravitational constant t 1 [] 1 a)/0 Headloss Coefficients for Manholes and Junctions These are typical headloss coefficients used in the standard method for estimating headloss through manholes and junctions. Type of Manhole Diagram Headloss Coefficient Trunkline only with no _/�^ 0.5 bend at the junction Trunkline only with 45 0.6 degree bend at junction Trunkline only with 90 0.8 degree bend at junction I Trunkline with one lateral Small 0.6 EI V Large 0.7 Two roughly equivalent 0.8 entrance lines with angle of < 90 degrees between / lines Two roughly equivalent 0.9 entrance lines with angle of > 90 degrees between lines Three or more entrance y -- 1.0 lines n u I APPENDIX E [1 SWALE/CHANNEL CALCULATIONS 1 [I t I ,E-/ ' SCENIC VIEWS PUD Worksheet for Trapezoidal Channel Project Description Project File x:\908200\swales.fm2 Worksheet DP 2 - EMERGENCY OVERFLOW CHANNEL Flow Element Trapezoidal Channel Method Manning's Formula Solve For Channel Depth Input Data ' Mannings Coefficient 0.035 Channel Slope 0.020000 ft/ft Left Side Slope 4.00 H : V Right Side Slope 4.00 H : V Bottom Width 4.00 It Discharge 31.30 ft3/s Results Depth 0.93 it Flow Area 7.20 ft' ' Wetted Perimeter Top Width 11,611 ft 11.45 ft Critical Depth 0.92 ft Critical Slope 0.021499 ft/ft ' Velocity 4.35 ft/s Velocity Head 0.29 it Specific Energy 1.23 ft ' Froude Number 0.97 Flow is subcritical. 1 1 ug 26, 19% None :43:32 Haestad Methods, Ina 37 Brookside Road Waterbury, CT 06706 (203) 755-1666 FlowMaster v4.1b Page 1 of 1 ' E7Z EMERGENCY OVERFLOW CHANNEL Worksheet for Trapezoidal Channel Project Description Project File x:\367600\fm\drainl.fm2 Worksheet D.P. 2 - 1.33 X Q100 ' Flow Element Trapezoidal Channel Method Manning's Formula ' Solve For Channel Depth Input Data Mannings Coefficient 0.035 Channel Slope 0.020000 ft/ft Left Side Slope 4.000000 H : V Right Side Slope 4.000000 H : V Bottom Width 4.00 It Discharge 41.60 cfs 1 Results ' Depth 1.07 It Flow Area 8.86 ft' Wetted Perimeter 12.83 ft Top Width 12.56 ft ' Critical Depth 1.06 ft Critical Slope 0.020657 ft/ft Velocity 4.69 ft/s ' Velocity Head 0.34 ft Specific Energy 1.41 It Froude Number 0.99 Flow is subcritical. 1 06/02/97 JR Engineering, Ltd. Fk wMasler v5.10 10:23:44 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 SCENIC VIEWS PUD Worksheet for Trapezoidal Channel Project Description Project File x:\908200\swales.fm2 ' Worksheet DP 3 - EMERGENCY OVERFLOW CHANNEL Flow Element Trapezoidal Channel Method Manning's Formula ' Solve For Channel Depth Input Data Mannings Coefficient 0.035 Channel Slope 0.020000 ft/ft Left Side Slope 4.00 H : V ' Right Side Slope 4.00 H : V Bottom Width 4.00 ft ' Discharge 66.80 ft /s Results ' Depth 1.34 It Flow Area 12.56 ft' ' Wetted Perimeter Top Width 15,06 14.73 ft ft Critical Depth 1.35 ft Critical Slope 0,019348 ft/ft ' Velocity 5.32 ft/s Velocity Head 0.44 ft Specific Energy 1,78 It ' Froude Number 1.02 Flow is supercritical. 1 1 1 JA u926, 19% None FbwMaster v4.1b 1 ug 4 7 Haestad Methods. Inc. 37 Brookside Road Waterbury, CT 06706 (203) 755-1666 Page 1 of 1 i E7_ y 1 EMERGENCY OVERFLOW CHANNEL Worksheet for Trapezoidal Channel 1 Project Description Project File x:\367600\fm\drainl.fm2 Worksheet D.P. 3 - 1.33 X Q100 r Flow Element Trapezoidal Channel Method Manning's Formula 1 Solve For Channel Depth Input Data 1 Mannings Coefficient 0.035 Channel Slope 0.020000 ft/ft Left Side Slope 4.000000 H : V 1 Right Side Slope 4.000000 H : V Bottom Width 4.00 ft Discharge 88.80 cfs r Results r Depth 1.53 ft Flow Area 15.50 ft' Wetted Perimeter 16.62 ft Top Width 16.25 ft 1 Critical Depth 1.56 ft Critical Slope 0.018611 ft/ft Velocity 5.73 ft/s 1 Velocity Head 0.51 ft Specific Energy 2.04 ft 1 Froude Number Flow is supercritical. 1.03 1 1 1 r 11 r rO6/02/97 JR Engineering, Ltd. FloviMaster v5.10 10:28:54 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 ES i CHAN. SECT. 4-4 (DP 9), 1.33 X Q100 Worksheet for Trapezoidal Channel Project Description Project File x:\367600\fm\drainl.fm2 Worksheet CHANNEL SECTION 4-4, 1.33 X Q100 Flow Element Trapezoidal Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.035 ' Channel Slope 0.020000 ft/ft Left Side Slope 4.000000 H : V Right Side Slope 4.000000 H : V Bottom Width 4.00 ft Discharge 16.12 cfs r Results Depth 0.67 ft Flow Area 4.45 ft' Wetted Perimeter 9.50 ft Top Width 9,34 It ' Critical Depth 0.64 ft Critical Slope 0.023661 ft/ft Velocity 3.62 ft/s ' Velocity Head 0.20 ft Specific Energy 0.87 ft Froude Number 0.92 Flow is subcritical. 1 r 1 1024/97 JR Engineering, Ltd. 03:45:26 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.10 Page 1 of 1 A -A XC 4 4, .33 X Q100 Worksheet for Irregular Channel Project Description Project File xA367600\fm\drain1.fm2 Worksheet DESIGN PT. 8 - SECTION A -A Flow Element Irregular Channel Method Manning's Formula Solve For Water Elevation 1 Input Data Channel Slope 0.020000 ft/ft ' Elevation range: 99.31 ft to 102.19 ft. Station (ft) Elevation (ft) Start Station End Station Roughness 0.00 102.19 0.00 9.50 0.035 ' 9.50 99.81 9.50 12.50 0.015 10.00 99.81 12.50 22.00 0.035 10.00 99.31 ' 12.00 99.31 12.00 99.81 12.50 99.81 22.00 100.00 Discharge 65.10 cfs (�Ioo (�•Jjl�=VF1'f-IVLS �. /NCt_ vjt� Eu77RE Results EX Wtd. Mannings Coefficient 0.023 ' Water Surface Elevation 100.52 ft Flow Area 10.03 ft' Wetted Perimeter 16.96 ft Top Width 15.35 ft Height 1.21 ft Critical Depth 100.70 ft Critical Slope 0.010144 ft/ft ' Velocity 6.49 ftts Velocity Head 0.66 ft Specific Energy 101.18 ft ' Froude Number 1.42 Flow is supercritical. ' Water elevation exceeds lowest end station by 0.52 ft. 1 06/02/97 JR Engineering, Ltd. FlowMaster v5.10 ' 10:4820 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 APPENDIX F SWMM RESULTS [] 11 1 J n I 0 m i 0 m 0 z a N N V V O V I I 1 I O u lino 3 oV l MVIU3AO I Z C Nu uy V O 6 3 OM3M O 0 a -1Y= l N )C�Z 1 2 1 1 2 3 4 ' WATERSHED 0 SCENIC VIEW P.U.D. 100-YEAR DEVELOPED, NOVEMBER 25, 1996, 1996, BKW: SV I OORET.DAT SUBBASIN #11 AND #12 OF WEST PLUM STREET BASIN 60 00 5.0 1 1. 1 24 5.0 0.60 0.96 1.44 1.68 3.00 5.04 9.00 3.72 2.16 1.56 1.20 0.84 0.60 0.48 0.36 0.36 0.24 0.24 0.24 0.24 1 0.24 0.24 0.12 0.12 1 11 59 320028.80 60 .01 .016 .25 .1 .3 .51 .50.0018 1 12 202 1359 7.80 40 .01 .016 .25 .1 .3 .51 .50.0018 1 0 0 0 59 202 0 1 2.0 1007 .01 30 30 .02 100 0 202 0 22 .1 100. .010 .0 .0 .022 .01 0.00 0.00 14.2 00.0 14.3 1.00 15.4 31 ' 0 2 ' 59 202 ENDPROGRAM t 1 )C�3 N O f� d' W P w 1' U W Z m W W N v 6 C O U MM A U P c w w � N S Z s w � w u W _ z O z W c O w W_ u N LL a w � W # y N N LL' N O Q K U i W i Y m m w O W J H W W Q 6 O � 0 0 � � u N � S P P 2 O r O v m m O f O f Q O K 7 U � N S O M SO f0 QO � U Z N 1f1 � O 7 N V v �O HO H Qom} C � O U Z M M S N H O O N N O H O r Q M 7 O O � � U N S ZO 1-O O � O N O K O N P P P P N N Y _ m £ W 6 am Z r W W O LL' N # O # J £ # � J J W 6 pW p J LL Y �O O U 2 O O ~ O z N 6 q d W 6' 7 O S H uZi W 2 m m H ♦ W m f # N N 2 � O I ry 1 i 1 1 1 1 1 1 1 i 1 1 1 1 1 1 1 W O Q W ^�-00 � O O z Y O O Q W W f O C £_ 2 £ O O r 2 r r C £ Y £ If�N 2XN� r Q Z> 2 O O .pb •+6'00 vWMM N 6 K O r N �! H f f O N O O O O O O b N r W N N d Y P � uQ. � ♦ m m m W U � J W P ¢ �•O P S P mz V Z 2 am N£ 6 x� 1' Z V� .O w K .ppO.. o O O P P o •ppO� 6 d P P £ •O m M M O P W O OON ^ 3 m O N N 2Nx � I(� N 61~i00 N N 2 OH Jf 00 2 M• Z m y • W� 2 m m� W m m r N r ZN �Zy N W ZN N OOLO ZH W d' 2r 2Y OC W� WYN N^ .-• m m N •Obr W W O OC U W O O O LL'6.Ob •O W Z •W W 2 � W H S � � W Im- m 6 W J O m N M m O £ Y O y g J U m O W 7 Q f LL 2 > J W 6 W U K Q m ti W > J W d f Q N W O W O > J W 6 K W bON O 6�N m• O [J x 6 p i a x a 1-• b •o .- �- �- ^ � m u p � �- WW Y > 6�- LL FYOPUQ O U 2 6 w K > W 00 pLLONY �+ p 0 LL ^ N 2 O 6 00 W CC h �- W m O ^N r N M Q< 3 M^UQ O N_ Y. N W W S � v LL W m • O N_ ^ 6 d' •p b P�N it m W W U OC U 1- Q Y `JW �6 p� 5 v r O � O •Y•• O� W Q£ LL LL> p > z K O W S Y O O 2 U v Y p w m O = r 6 H<PN Q d 1- W J K x W f d H Q W Z ZG[O O W 6 ^ w W_ 3L O S N O w f O N W M 6' m m z W � W_ i! r J y 6 LL Z f J �. m m W U Q LL Z O U 3� W iG U b 0 O O b O y p LL Y 6' H OCN` •ONN >`6• >^ O C m ^ N O OC 6 OC W J J Q U C J J J J 6' Q � � H H W m t h f H h W m z moo LL u u> m N .M oo m Z r H u. m N • ♦ a 3 o f 0 r 0 f o 0 m w W u� N N O O O � 0 0 — � �S 1 1 t 1 1 1 O O W O C Q x U O r LL O r N d \ W v O Y p O 2 � 6 0 K W O 2 O N N N 2 2 O O aZ i } C 4 w 0 0 W > K 6 O O O M J f N N O O W � J � O M N S w u o 0 2 O \ W J LL O O > N v J JO f f p LL N 6 p 3 K v J 3 O J 6 N O J W Y- 2 W 'ZQl •Wd.•LLN U 6 W U 6 Z Z W O O O N N 6' N 2 ONTO•-• 6' 6 W \ N N W 6' 6' W � O T W h H U N O H W O J S N O oz O K U Wm 2 K K 1W- Wm P N Q H £ N O H O Z O r Na O LL H } 3 J 6 N N w J Q u � O � O C ti W W O O T K K S O Q H O F j O W (O pQ W •-• O O H p LL H W NN�-4 P O W LL W K W� 2 N p 1 r O C N LL W= U y LL= LL N y Cl O U O W 6� 2 6 Z W y S W Z S 1-• O r O •-• Z W •-. W • W 2 W m r O W 2 Q W 6' W 3p 6 N J 4 W U o M o H O O OJ M- U W N y W 6 W p O N N N N N p S W W W W W O s fynl rr00000 o O O W W N 3 T LL W W W W . Wp p O O O O m sm O O p 6 3 � W_iG S rr > 2 Q \ N O Q O W m O £ O O N N 2 H 1 1 1 1 1 1 1 A �1 O• M O CD O N M �t . . O O O O Or ON OM O� Opt ON ON ON O.O OHO O.O O.O O . M1 ' . N • � • �' '.- p0 •O • N � . M N N •O ' ' O O N f 7 N N N N N N N N N N N N N N N N N N V1 �O A A m CD P P P P O O O O O O �O O�G OHO OV OHO OHO OHO OHO OHO OHO OHO OA OA OA OA OA OA O M M M M M M M N N N N N N �t d N Y1 N N M M M �T N 1f1 F8 A OA OA OA OA OA OA OA OA OA OA OA OA OA OA OA OA O M M M M H H M M M M M b b b b b b �- � N N N N N N N N A O A O A O A O A O A O A O A W J U O O O O O O O O S O O O O O O O 4Q O K 2 O N O Y1 O N O M M �f �t v� in (.� O C �t �1 d d d .f 6 N O 2 W ,C/D I [J 1 1 2 1 1 2 3 4 WATERSHED 0 SCENIC VIEW P.U.D. 25-YEAR DEVELOPED, NOVEMBER 25, 1996, 1996, BKW: SV25RET.DAT SUBBASIN #11 AND #12 OF WEST PLUM STREET BASIN 60 00 5.0 1 1. 1 24 5.0 0.48 0.72 0.96 1.32 2.28 3.72 6.84 2.88 1.56 1.08 0.84 0.72 0.72 0.48 0.36 0.36 0.36 0.36 0.24 0.12 0.12 0.12 0.12 0.12 1 11 59 320028.80 60 .01 .016 .25 .1 .3 .51 .50.0018 1 12 202 1359 7.80 40 .01 .016 .25 .1 .3 .51 .50.0018 0 0 0 59 202 01 2.0 1007 .01 30 30 .02 100 0 202 0 22 .1 100. .010 .0 .0 .022 .01 0.00 0.00 14.2 0.00 14.3 1.00 15.4 31.0 0 2 59 202 ENDPROGRAM 1 /::: I 1 1 r 1 1 s s u N -a 2 A P P P m �n N H � 'a 20 YO QO f ' O O z U A ? O W O W > O J J 2 p Z N N LL Y N W LL U' OC 6' 20 r0 N p O OC O W = W N m z w N « « n o M M « w J 2 N H O J W > 6 W S p� O O W (29 N N U 2 N 1- O W� S O rj- 0 p Y LL W W W 2 m m 6 Y ♦ W m N r O � 3 « N 2 O I 1 1 1 [1 1 y 6' W F M x N •O A M _ Z rc M f £ W 6 6 W O O O y • W Oy0 m•O F• H O O > Z N O K O N 2 - 2 � y Q W J •, Q M LL S mWQ � •O NN v 6 x P A W F w y .z. n s ^ J W J m £ LL IaL � 6 W U �lO m�tN r CN2 �tm� � m 0 6 OC W O O O O O O a p pP P y N p •> 2 nQ W i2 > Z W H O O 60 \ O O J M O O yV a a p p f r W W Y K N y J W gs a P � U 6 O O �t •O O O •O N M •O O P O M M N � y N � W O y W •-• is = s J sa W • LL' H £p W .00 OY m O O j W U S Q W �- y J y + = z W 2 y 6 3 w v u 4 3 N LL O •+ U 3 Q W i• LL O LL GJ � O N NN_ Y y W W S n• v W W m N NN_ u p S .2.. O O .~• O� Q Q 6 r W J OC x WW W f 6 6 O 3 W it ` y •-• W W U W 3k m i y u y O y U m Z m O W Q 6 Q 6 O S m W m • H 1-• f H 1� m W m u= y y ♦ • Q 3 O O O O K U F13 1 1 1 1 pp w O m a 2 W .- \ W v O Y O O Q m C > O U 2 O N N N 2 $ O O 2 . . H C N W O O w>z 6 O 00 M r m O rc O — O M N S W LL O O H 6 O O rc O \ W J LL O O > VI 2 .+ f � 2 LL O O J O 2—� •r P O LL N Q O 3 n v 3 0 a h ?o W f z w x W LL U 6 U � Q 2 — z W uo a O N N 6' m 2 ONyO•-. s a W \ m m w oe R' W z O r W H O 1-U NO z N O O K U W K K $ IW- m P N 6 U Z N O O 6 O F- W C N N Y m P u� N 0 0 0 0 0 0 0 0 O J O Q_ J 6 N N w p S � d J Q _U C f O 6 K O W p m F C i W 6 N ^ J H m p $ J K Y £ W p = i p LL r p a u P s � ow Huai um.a W •• W w£Oa2i wLLwcr� u 2 m O LL OC N Y U-1'IA>d' v+ > o r LL u p LL w 2 U 3> LL� LLI~i W N LL 0 2� U U O Q� z_ 6 w oQG W O f O O •+ 2 W •-• O£ O u WJ —2 m > 6 W p O N m N N N W 2 W W W W Www 00000 O O O O C y 1 K Z z z z z N Q 3 O C W W W W W W W O O O O O Wmm O p 6 3 W W W it S H 1-• — — 6 O W m O £ O O U J m m Y S H I y 1 O .M .� M .O O .O O •N O O .O O- .O Or •N ON .O OM .M OM .m OM .O OM .O Od .N O Opt Opt Opt O A ^ V O ' O N O M O N O N O N O I!1 O N O N ' )5/5 1 N N N N N N N N N N N N N N N N N P P �t Opt Opt Otl Od Od O�i Oq ON OY� OII� ON ON ON OV1 ON OIn O N N N N N N 14 O N O U O N O N O N O N O f-�Al N N N N N N N N N N N N N N N N N 1!� ON O1/� ON ON ON ON ON ON ON O� ON ON O1l1 ON OVl ON O N O ^ N N M M Ct N YN N O N O W N N i /7 1 1 1 1 1 1 1 0 W N > Y m N £ O P P z O N z P p W •Z• O o O � \ 1!1 2 f K LL' 2 N fG N w £ Q f W ^ > > 6 woe O N v W N 6 N W O Ey G O � to 6LL V� O N O N O IlI O Vl O N O Ifl O M !A Fv 6 3 z H w W Q J Y LL J O O O O O O O O �� F Qlyi NO yQ O O O O O O O 0 N wa U O K 0 a � n w iG IL £ a W 2 m O 6 � N N • � W t 5 1 1 1 1 2 1 1 2 3 4 WATERSHED 0 SCENIC VIEW P.U.D. 10-YEAR DEVELOPED, NOVEMBER 25, 1996, 1996, BKW: SV 1 ORET.DAT SUBBASIN #11 AND #12 OF WEST PLUM STREET BASIN 60 00 5.0 1 1. 1 24 5.0 0.48 0.60 0.72 0.96 2.16 3.12 5.64 2.28 1.120.84 0.72 0.60 0.60 0.48 0.36 0.24 0.24 0.12 0.12 0.12 0.12 0.12 0.12 0.12 1 11 59 320028.80 60 .01 .016 .25 .1 .3 .51 .50.0018 1 12 202 1359 7.80 40 .01 .016 .25 .1 .3 .51 .50.0018 0 0 0 59 202 01 2.0 1007 .01 30 30 .02 100 0 202 0 22 .1 100. .010 .0 .0 .022 .01 0.00 0.00 14.2 0.00 14.3 1.00 15.4 31.0 0 2 59 202 ENDPROGRAM 1 1 1 1 a o z s �J o U N l 2 A P P P w ^ E m l W P N r W 2 6' • � O U p 2 W ^ P W •.r pC OC 2 O �- O N _ O 6 P N Y N W 2 f 2 O U 1- •O •O M �O w - p •+ O - N O 2 •O i s - o z w m o w w >_ u LL Y N W LL O EC OC 2 O f O 1I� ♦ N ^ m _ m N J K C J •t � v! U � W � d' N J Z O F O Q •1 2 W O � S J 3 J s S o00 N O f z wN + 05 W M M J J 6 •!73 2 N f O W W p r p m W J W W •O W 6 p S 2 ^ ^ 6 O 0 Y W Q N y0 HO 6M Z C d W 6 Q �O O 2 O h O p Y d' LL 7 M O W W W 2 m m Q f O � Q 3 • # U > N N 2 O i rzd 1 1 1 W O V W ^F-00 \ O O 2 Q O O 1 W W ap c £ z £oo O •-• N N 4 £ OJ 2 X Z > O O ••d'00 W 6 ^• Q. 1 O r N > OC O O W W O O N F = W K m W K w K O O O 1'>00 .ON Ud r Y m W Y m J Y m U W Nd' .O 6 C•O .O •O O � 001N P WLLOO O• M ' ^ O U .O •O N O\ � � N J N H •-• m VI m N wm ti 2 J £ q 0 oar >c wm > = 2>00 > u u wm O�- N OF d' W WHN •O m N P.t� S W W U W O O O OC 6.O � •O 2 W W K 2 2 W W 1 NZ� mod• W£ `OC f £ q mod' ••• 2 m O f W N 6 �• •O M O f W VI £ W O d' d' O 1- W N N W S= J O£ O£ 2 N O O£ O q 1"• LL W J W U W J H VI LL W W J 1 i OCW� NON W 6`••N N W U S < W axa r C n•o� p� N Z N N ^ 2 2 2 N N d' W W W O O 2 O N_ S dm 6' OON mW U 6' U =J W £ LL d] O 2 w S N J S r O N Y J 2 f 2 H w W 20C 6 3�" HgPN q 7£ N O W H O ND m 6 3� H j W < J u OC S K W LL f O 6 3 1 aaO W it m W it 2 •-• LL U W it U �}(.J wmm O gm O F 2 2 > 2 Q W N2_ vn� >2 a ZF >2 2 2 K •Z+ 3 N C 6 Q uw W. C yw O fA ^N m W K O Q Z m m W J J 6 m N 6 6 < z m U m W J q J q J 6 J < 6' O q z m H • y. y •- 00 W m u> m£^^ H f » 00 W m U O k r H 6 H O H O 0 O H O d' o[ W m U O y LL LL NN N 2 H0 !nN k 3 f r f W NN 1 O O O ' 0 0 — ^ 1 1 1 1 � N M w u z a p o 0 x U U r LL O .- N 6 \ W v O O O Y p O 2 Q � m O O K W O O 2 O N N N O O 2 2 O O 2 i O O f K O O f W>n' 00• 6 O O O M ¢ a N O O Q W �• 0 6 J O m O M N O O 6 N 2 N Y K N W O O O O O O n F n LL O O m J Q w O \ W J H O O OC U s 3 O p p w p u a w w a3x F V J � O N N O 206• LL •� O W £ Q •'. O O r m O O m VI f Q •� 2 O O u f _ H > 2 ggp 6 •• W W p O U N P P 2 Ul O W w n' N 2 W 1fl O O In > O H LL U O w. 2 6 LL U y N U n w Kd K= w m N N n O O K 2 m N N N 3> W LL 3 u u J•-•U U ow 2_ O f N O r U' � p� 3 W •-• 2 W � n' f � . Y 3 n' W O f O n' 6 U• 0 0 Q O H W N H 7 6 O h W (n O J K 6 W S 6 Q h U S O M O O m y N N > 6 W 6 f O O 6 W W 2 O O N N N N N W W W W W O 6 O W Of N O p f H NI�Fl-1-• h N O 2 ONO > a N OC W f 2 Y N OC W w .. 00000 2 3 2 2 2 O N O O OC 6 6 2 W OC Q 3 O w w W W W W W W \ W £ 6 O O W W W o Opp O w YO c2.f YO C W O h• m O W p O O v v v _ O O ~ N W 1-U NO O O p N O p J W W 63 m O O 6 O O 2 N O 6 Q O 6 Q a J J U W £ W W H O. N 6 ~~ £ > > £ O m O O U W W J Q 3 4 O N N N N N N N N N N N N N N N N N O N O 1!1 O N O N O Ifs O 1!1 O N O N O O O O O O O O O J 'Z3 N N N N N N N N N N N N N N N N N Y1 �p �O A A A aD cG tC aC tU P P P P P OP M OM OM OM OM OM OM OM OM OM OM OM OM OM OM OM OM O M M M N N N N N N N N O N O N O Y1 O ' O Y1 O Y1 O N O V; O Fzq N N N N N N N N N N N N N N N N N P P P P P P P P P P P OP P P P P P ' M O M O M O M O M O M O M O M O M O M O M O M O M O M O M O M am O ' N O Ct k4 O N O W 'A N N M MI N Y1 N N lr�zS 0 0 N Y i Y Yto m Q J O P P z O � y P W 2 O W_•• OO J y W m N K W z w O U M z O my o f- W N 6 N W O £ O N N N 41 N N N N J � W J Q 1' P P P P P P P P.- o M O M O M O M O M O M O M O M m 6 = Z f v N W Q Y LL o w 0 0 0 0 0 0 0 om m wau a W ik LL 2 2 U m W > J N N Qm 6 20 W S W m U � M U 41 m n 1 1 1 1 1 2 1 1 2 3 4 WATERSHED 0 SCENIC VIEW P.U.D. 5-YEAR DEVELOPED, NOVEMBER 25, 1996, 1996, BKW: SVSRET.DAT SUBBASIN #1 I AND #12 OF WEST PLUM STREET BASIN 60 00 5.0 1 1. 1 24 5.0 0.36 0.60 0.60 0.84 1.56 2.52 4.68 2.04 1.08 0.72 0.48 0.48 0.48 0.36 0.36 0.24 0.24 0.24 0.12 0.12 0.12 0.12 0.12 0.12 1 11 59 320028.80 60 .01 .016 .25 .1 .3 .51 .50.0018 1 12 202 1359 7.80 40 .01 .016 .25 .1 .3 .51 .50.0018 0 0 0 59 202 01 2.0 1007 .01 30 30 .02 100 0 202 0 2.2 .1 100. .010 .0 .0 .022 .01 0.00 0.00 14.2 0.00 14.3 1.00 15.4 31.0 0 2 59 202 ENDPROGRAM i= Z(o FZ-7 1 1 1 1 n P K W + m 1!� w P N f P W v J 2 � • m W W w LLO � P a u W N 2 S N 6 W U O Q u u o £ P N N 2 2 U r W W •� U GC 2 O U U w U ? O W O W_ _O • LL N } f N Y = = S O ^ r o s i u N � Z P P 2 O r O m m v O F O f 4 O u OJ �l N z � n Z O H O Z O f O H Q O K � U N N ZO HO � v v h0 f 6�1 ^O K � u � z M M 2 N H O N N �O H JO KM z Z O r O O �f O � N Q w rc N > N m d P P N N K W N ma £ m O w z w z p N M d £ • O m J J J W 6 W > p W f W LL Q J W LL a o Yo 2J Ft w p N ? w 6 w p 6 W 6 £ W z S H N Z U N m W Z m m r M W m £ 3 � • N N Z O .1 1 1 1 1 11 1 W O W .-•moo S 6 m m \ o0 2 T O O •+ U W W O d' £ J 2 £ O O Q £ K ti £ J � i�� 2XNN • • u Q £ 2 > O O •� d'00 N N v W M M O Q K O N > GC O O W W O O �1N O N tJd�•- 6 £ N Q s 6 6 O y O O W W W K K> O O C K •p N N U d N ♦ N Y W Y J Y m lJ • 2 > � m W 8 m W � •O � W � •O Z •O S 1' F• £ W N� N u d' ` n N O O O N •O �t t0 •O N � O 6 6 •O £ •O N M O O •O OOW p•O� P ONU •O .O O\00 � y NM N Jf00 N Y N O W J 0 Q m Q S J m Q O p 6> S m f £Cl H U J LL £0 N W O •O N O W 2 W U W O O O d and • .O O W 2 W OC u v Z > F O W 2 W N22 m •� C d� •O .S £ O •� d£ S N O 6£ O Q f LL OJ J W U �• �• OJ J H N W OJ J 2 W 2 d' W O t0 N W d > K v m A � 6 N N W 6 > Q U W 2 O U' Q W d > £ 6 2 6 .O .t W f f •+ W f m U O W f f d' H O N 2 N O N J H •' • � 2 W 2 p N J rc3 £ d' z3 W � U oe3 Q N Q S •"• • S U 6 W LL d' O � S U f 4 d• W Q W d W K r r 0 O W N M a v N O d N W 2 W 6 Y O 1- WN NN 3vM�U6 NN Y W S v LL O Y1N 2 6 d' £JW O W N •O �}� •aC m W W mod' •� U W C U U 2 2 f 0 6 > F •iC J p] p J V! Q O S v O O 0 p 1- 6 �-• 6 P N Q 6 �- W J C x W F 6 2 H 6 W zd'O .'• 3� W it J£ N O M H O N W J v 3•- W it � O 2 C 6 LL 2 f J N W W U 6 LL Z O U 3•- W it H U�}IQ'J m N 2 • Wm M d > Y O �m O d' > f W 6 Q O > K 2~ W M N m 4 U N d' U N O N U 41 W O 2 m 6' W J J Q m N Q Q Q 2 m U w W J Q J Q J 6 J Q 1• O .-• Q 2 m r .2.. 0 d' � 0 0 W m U O N N m£ � � M F >> 0 0 N 2 W m U O N N Y ♦ ♦ F 6 •j f O H f O f H O f O f n W' U O N N O O O '. O O^ F2 9 1 0 0 � m •O N M w a u z o x U O H LL O �- N 6 \ W v O O O Y p O Z Q m � O O K 1 W O u Z O N N N O O 2 2 O O Q2 03 w R' O O N W W > K O O J O O M ' w O O 3 N O O Q (A S VI T K N Q W ' ^ W O O O J 6 LL so\ oo m u� wJLL > N oo m f N zm O Of Ao w w u w Z 7 w - u W £ � 7 LL • . T Z - p W ' N Vl W �- O W WS O •O O O lc�W y N> d' W f W OW- O 2 w O O > O H d U p d � N N Z Vl N 2 U 3> LL� LL LL U d��} W N 6 O O W N N W OJ �U3UU O- Z W- - O W O O O W ` W m - U' d N S W w W Z W W S Q W 6' W O < O uo •�- �- mot- o z x<Wx6 Q K N p N W O U• 6 \ O O p m W J J < d '- d• H U d' x O d O N O o d£ d£ o u wwm-w f N O 7 O W O J N W p N O O N 6' N W d > Q f � O O W 6 > = p0 N NY1NN W W W W W O ' 6 p O ONO 6 ON r ON --00000 O O O rc a c 3 w z rc 3 O z c w w w w w N m W d S f O O W LL m m O O p O O 2 S w m N N W i v v v v Ov v K - WO O N O � S N O 6 ? 6 K O U W m Z � W it f Z W F• = � W it N x x S H �- Z ' • . J >^ £ 2 u W O N u u 6 W W J < 2 6 O H m P N Q Z m Q 2 m m W O N O u O N m w < u J N W > S £ f O O O! ^ �3D 1 1 1 1 1 1 1 1 � O O � O� O O O� Or Or O� ON ON ON ON ON ON ON O O O N M v! N� O Y1 O Ifs O N O V1 O O V1 O N �31 N N N N N N N N N N N N N N N N N N ON ON ON ON ON ON OM OM OM OH OM OM OM OM OM OM O N N J J J M M N N O V4 O O �4 O J J N Y� N N M M J J Yf Y1 F32 N N N N N N N N N N N N N N N N N M O M O M O M O M O M O M O M O M O M O M O M O M O M O M O M O M O O O O O O Ifl O N O N O N O Ifs O N O N O I(1 O V� N N M M O d in 1I� �- •- N N 33 1 1 1 1 N N N fA N N N N M am am am am am am am O O O O O O O O O O O O O O O Q w N N i Y Z m O •O 2 P O P � N 2 Z P O W O O N Q 2 O N N Z � v K W N W (L 6 f W •+ wm � aW ow ou rn z O w v O N N W W 6 £ o� O a J J OC w N 6 LL p w ¢ 3 2 w v m a a W LL Y O N w Nit H QLL NO p N Wa v • O p Q N 6 3 2 J U_ _z U N W > J N N Q 6 Z W Z Ql O W m u � i i U 41 N i 1 2 1 1 2 3 4 WATERSHED 0 SCENIC VIEW P.U.D. 2-YEAR DEVELOPED, NOVEMBER 25, 1996, 1996, BKW: SV2RET.DAT SUBBASIN #11 AND #12 OF WEST PLUM STREET BASIN 60 00 5.0 1 1. 1 24 5.0 0.12 0.36 0.48 0.60 0.84 1.80 3.24 1.08 0.84 0.48 0.36 0.36 0.36 0.24 0.24 0.24 0.24 0.12 0.12 0.12 0.12 0.12 0.12 0.12 1 11 59 320028.80 60 .01 .016 .25 .1 .3 .51 .50.0018 1 12 202 1359 7.80 40 .01 .016 .25 .1 .3 .51 .50.0018 0 0 0 _59 202 01 2.0 1007 .01 30 30 .02 100 0 202 0 22 .1 100. .010 .0 .0 .022 .01 0.00 0.00 14.2 0.00 14.3 1.00 15.4 31.0 0 2 59 202 ENDPROGRAM �=3s- ao j U n P P P w .. — m £ in N � � r P y aD m r z v j C U N 20 1-O �O W y P � O f W N 2 S r A C U 1� Z P N n a z W U 1' 20 HO QO P p O N U 2 u O S LL y LL .1- Z p N # # W d £ N W £ J W LL W Q N 2 0 r 0 O Q 00 00 u ¢ O pp J N lS'J N Z K ? Y W 6 W W_ it 20 W 80 W W 2 m m f O � Z f N N Z O )=3(o e i wo w � � p 2 Y O O V w W O Q 2 £ O O O •^NN C £ 1- £ z > o O �eN- vwMM w 6 O N > 6'00 OjN W W O O U6�� H - 6 d' p N W d' 6• > O O N N N U 6 � M w m U N6' QC•O .O W •O F- W � � N 6 £ 6 •O S w O P O O f/1 O• •'• W W H O O ` fON � N yv00 W 2 w w O p 6 Y £ m H N=N �ON� SW O[6.OV •O N p N M N = W J £ W N r 6 0 0 Q •+fA l0 N W W W > d W LL r r O P U Q d' > W NN_ 3 M�w 2 dy LL• �p •pN ' MM� n£iJ0 p� J N < S LL> > 2 W 2LL Y z O Q 2 2 CO 3� t=•JNN W O ' UV N•ON !� 6'N2 OC d Q U N 3 - O O U J U O^ 00 ' LL e- N N IA 2 F• F• N � p H f W W K N K N N w N s = Y J Y (O m SW � £ d P U P d N O O O •O M O P A W A O P N •O � P M N = N N N W N = W W N O] 6 £ m H 2 U J J m 6 £ N >1- _O W y £ H W O J U N O m O J W 6 > 6 u W 2 O 0 4 W 6 > W F• 0 U p H W r p N O ••• = 2 2 O N NN Y w S v u (Wj NN •at w O z z •at p y 2 6 Y Q J 6 W Q < W it 2 •+ W LL U W U .2i S O N O N 2 UI O W a a 6 Q O z ao W m u D • • H 4 h O H O H O H O w W 0 U O N VI i 3 r f Y f W^ N N )�37 O O U m •O .Q.r W 6 O d' 6 O O O x y d O O \ W v O u p O 2 6 � m p O C W O Z O N O O N N Z 2 O O Z 6 . . £ O O O u T ¢ p m• O O �- W i d' n 00 O M y W O O Q J N O O Q W •J m J O M y O O 2 y S Y y K y 0 00 m J6 CO\ W J O O R' U 6' Z m LL ti Q f G W p O T o rcx O . 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O Y U w c O Z O N K LL' U y U U y m O w S Y m P N Q 2 m 6 Z W O r-3S, 1 1 1 1 1 1 N N N N N N N N N N N N N N N N N O O O N M N V — — — M M M M M M M N M N N O N O N O N O Ifs O N O N O 11� O N F3 N N N N N N N N v v N N N v N N v1 Li A f� A A A A f- A A A A � Or O� O� Or Or O� Or O� Or Or Or Or O� O� Or O� O N N N N N N N N N F qc) N N N N N N N N N N N N N N N N N f� A A N Cl m Cl Cl w m m m Cl C) C) 0 m O O O O O O O O O O O� O O O O N O Y1 O N O N O ` O N Fa! / Q 0 N N Y Y Y S 0 G •O 2 O � N 2 ~ ^ Q • O O O � \ N v Z K K O O w O U .1- p W W V1 N (n N N N Vl N OJ C o� o.- o� o� o� o� o� W� �' aLL • z 3 2 H j a a W LL J O N N O ^ U O O O O O O O Q y N £ O O O O O O O N G v M O ?= • Q a N � � a 1- W K O N O N O N O 7 2 Y Y£ P N V �t �t V �t �t In W m ♦ U pLL U � N N • ♦ 2 W I /N Pu7 D/4i)4 ? I 1] 1 1 1 [1 1 �I 1 2 1 1 2 3 4 WATERSHED 0 W. PLUM ST. BAS(CANAL IMP INCLUDING BULL FARM POND 180 1.0 1 24 5.0 0.60 0.96 1.44 1.68 3.00 1.20 0.84 0.60 0.48 0.36 0.24 0.24 0.12 0.12 1 10 201 3485 40.0 1 11 59 320028.80 1 12 202 1359 7.80 1 13 62 272312.50 1 14 61 224812.95 1 15 63 1115 6.41 1 16 68 2248 9.29 1 17 64 888 3.26 1 18 65 967 4.66 1 19 70 803 4.61 1 20 69 1693 6.22 1 21 71 1176 4.32 1 22 74 146710.13 1 23 204 290 2.07 1 24 78 1516 2.61 1 25 76 2317 3.99 1 26 83 1394 2.40 1 27 79 1612 7.41 1 28 82 1210 2.50 1 29 80 1630 7.11 1 30 87 1320 4.85 1 31 86 172811.92 1 32 206 259211.85 1 33 205 2091 4.84 1 34 207 189215.20 1 35 90 1431 6.57 1 36 89 1297 6.70 1 37 93 1162 7.64 1 38 97 512 0.47 1 39 96 501 0.46 1 40 98 1851 8.50 1 41 115 3438 5.92 1 42 95 1531 4.92 1 43 99 1036 6.54 1 44 102 1574 2.53 1 45 103 1500 3.10 1 46 104 1334 2.45 1 47 111 784 0.72 1 48 108 1554 2.14 1 49 107 161211.06 1 50 109 1297 5.36 1 51 110 1597 2.19 1 52 208 1632 4.12 1 53 113 1612 2.22 1 54 114 572313.14 1 55 117 1057 1.82 1 56 118 639 2.67 &)E�S-j Pc-,) Cj2e-0<- MA-sTVe- P"k-,) . BAS.)100 YR FULL DEV.COND, 4/15/96, plum100.dat (48" outlet and 10- spillway a 54.0 no clogging) 1. 11 5.04 9.00 3.72 2.16 1.56 0.36 0.24 0.24 0.24 0.24 30 .020 .016 .25 .1 .3 .51 .50 .0018 60 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .009 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 50 .010 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .008 .016 .25 .1 .3 .51 .50 .0018 50 .020 .016 .25 .1 .3 .51 .50 .0018 50 .020 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 80 .020 .016 .25 .1 .3 .51 .50 .0018 80 .020 .016 .25 .1 .3 .51 .50 .0018 30 .015 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 50 .015 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 40 .015 .016 .25 .1 .3 .51 .50 .0018 60 .020 .016 .25 .1 .3 .51 .50 .0018 50 .015 .016 .25 .1 .3 .51 .50 .0018 30 .015 .016 .25 .1 .3 .51 .50 .0018 40 .020 .016 .25 .1 .3 .51 .50 .0018 50 .015 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 50 .015 .016 .25 .1 .3 .51 .50 .0018 60 .015 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 40 .010 .016 .25 .1 .3 .51 .50 .0018 0 201 60 6 2 .1 1. .010 .0 .0 .022 .01 0.00 0.00 0.09 7.0 1.25 14.5 4.48 19.0 7.15 20.0 9.82 650. 0 60 202 0 1 3.0 450. .020 2.0 2.0 .045 100. 0 59 202 0 1 2.0 1100. .010 30. 30. .020 100. 0 202 0 2 2 .1 100. .010 .0 .0 .022 .01 0.00 0.00 14.2 0.00 14.3 1.00 15.4 31.0 0 63 68 0 1 2.0 540. .010 30. 30. .020 100. 0 68 203 0 1 2.0 446. .008 30. 30. .020 100. 0 67 203 0 1 5.0 281. .009 4.0 4.0 .040 100. )r-- L13 A P_ K W £ c0 U W P O K �— C 2 A W W Y N i W W 2 W P F LLO � J C O W p w N N 6 z W U O v y K F M U O x P N £ W z O w w r O O N z 2 U f Q •+ 2 O W U � U •� K •� U = O W O = Q = F Y u N w u t'l K C o c o o w w N 2 N O w W Y J 1 J w fWJ W 2 6 2 Y � O O r U W C (L F 6 Y m 2 J W £ f O w IZ'1 2 W O O 6 � Q K Y � N z W p O W 6 1¢- O a o J O U N � 2 P P 2 O ti O O O m v zo ro h ao 7 U = A A Z O H O 20 HO r 60 � � O 2 N N N v v v O f O F Q d K � O U = M M 7 N N F z "] U z D C O •� o m E m a u � C P O N v N T p lG � O u� > a W N OJ O_ LL � C Y: 0 } O CI Y O 4 f � 7 � J W N Q 8 m � £ W J LL LL O p O J LL y Z rc o uLL � O ~ N N GC W 6 J W d O 6 m £ � r N W C Y O W d J f Y U £ x /Z:: 4/y 1 1 i 1 1 1 1 1 1 i 1 1 1 1 1 1 1 O w o -------------------------------- Q W s ammmmmmmmmmo wwow w�mromaoorommmmmmmmmmmaoo xrc� \ p00000000000000e0000000000000000 2 YOO.O.O.0.00. 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N Nit �}VNbNNNNNN�i �}NNNNNNNNNNNNNNNNNNNNNNO 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 M M M M M M M M M O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O M O ss s 33 ss ss s J LL LL LL LL LL LL LL LL J J J J LL LL LL LL J LL LL LL LL LL J LL J LL J LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL A � u u u u o .. U f f" f U f f H f f H f F U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U 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 O 000eooc0000000ccacoac00000000c000000c^ w J J O 2 6 J U O N.O fOVtO.lAOONOA.1.f.1H-PmPPtO OJONOO�OJ .1 A.t .OP A.fNO 6 � �tOr M�N�NNM�t M�iMMNN��.t �1NMNNNMNN�MAA 1' O � O O 2 6' W 6 £ 6 A U N�}M•-O PlOA �1MNPOAONMOPA.OMNOPN�Od�OPNNdMN�N � �OOOOOOPPPPPPPOONN(O NeOAAAAAA.O .O .O �O 0 .0 .00 u O 6' K O U O t rl J 1 APPENDIX G EROSION CONTROL 1J I e 1 1 1 1 1 'J i 1 RAINFALL PERFORMANCE STANDARD EVALUATION STANDARD FORM PROJECT: SCENIC VIEWS PUD COMPLETED BY: DWK DATE: 05/20/96 DEVELOPED ERODIBILITY Asb Lsb Ssb Lb Sb PS SUBBASIN ZONE (AC) (Fr) (%) (FT) (%) (%) A 0.37 130 1.8 B 5.27 1100 1.5 EXI 1.06 280 2.7 C 8.19 530 1.9 D 3.03 530 1.8 EX2 1.32 625 0.8 E 2.93 300 2.7 F 3.50 210 2.9 EX3 6.50 500 3.0 32.17 552.E1 2.2 1 80.9 1 PS is taken from Table 8-a (Table 5.1, Erosion Control Reference Manual) by interpolation Therefore, an Erosion Control Plan will be developed to contain 80.9 % of the rainfall sedi- mentation that would normally flow off a bare ground site during a 10-year, or less, precipitation 1 event. 1 1 1 1 i 1 11 1 1 1 1 JR Engineering, Ltd. 4812 South College Avenue, Fort Collins, Colorado 80525 EFFECTIVENESS CALCULATIONS PROJECT: SCENIC VIEWS PUD COMPLETED BY: DWK MAJOR BASIN EROSION CONTROL METHOD BARE SOIL ROUGHENED GROUND ROADS/WALKS GRAVEL FILTERS SILT FENCE STRAW MULCH ESTABLISHED GRASS HOUSEIDRIVE PS EROSION CONTROL (%) DEVICES 80.9 STRAW BALES GRAVEL FILTER GRAVEL FILTER FILTER C-FACTOR P-FACTOR VALUE VALUE 1.00 1.00 I.00 0.90 0.01 1.00 1.00 0.80 1.00 0.50 0.06 1.00 0.08 1.00 0.01 1.00 SUB AREA BASIN (Ac) A 0.37 B 1 5.27 EXI 1 1.06 C 1 8.19 STANDARD FORM B DATE: COMMENT SMOOTH CONDITION CALCULATIONS STRAW BALES HOUSE/DRIVE ROADS/WALKS STRAW/MULCH WEIGHTED C-FACTOR WEIGHTED P-FACTOR EFF GRAVEL FILTER HOUSE/DRIVE ROADSIWALKS. STRAW/MULCH WEIGHTED C-FACTOR WEIGHTED P-FACTOR EFF GRAVEL FILTER HOUSEIDRIVE ROADS/WALKS STRAWIMULCH WEIGHTED C-FACTOR WEIGHTED P-FACTOR EFF GRAVEL FILTER HOUSEIDRIVE ROADS/WALKS STRAW/MULCH WEIGHTED C-FACTOR WEIGHTED P-FACTOR EFF 6-z (970)282-4335 0627/96'i r:G 100% 0.04 0.19 0.14 0.03 0.50 98.55 1.07 2.32 1.88 0.03 0.80 97.77 100 0.02 0.00 1.04 95281 1.82 3.30 3.07 0.03 0.86 97.70 X:\908200\QPWEFFECT.WB2 PAGE 1 OF 3 1 1 1 1 1 63 JR Engineering, Ltd. (970)282-4335 4812 South College Avenue, Fort Collins, Colorado 80525 EFFECTIVENESS CALCULATIONS PROJECT: SCENIC VIEWS PUD STANDARD FORM B COMPLETED BY: DWK DATE: 06/27/96 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 - SILT FENCE 1.00 0.50 STRAW MULCH 0.06 1.00 ESTABLISHED GRASS 0.08 1.00 HOUSE/DRIVE 0.01 1.00 MAIOR PS EROSION CONTROL SUB AREA BASIN (%) DEVICES BASIN (Ac) CALCULATIONS AC GRAVEL FILTER D 3.03 GRAVEL FILTER 1000/6 HOUSEIDRIVE 0.43 ROADS/WALKS 1.14 STRAW/MULCH 1.46 WEIGHTED C-FACTOR 0.03 WEIGHTED P-FACTOR 0.80 EFF 97.27 GRAVEL FILTER EX2 1.32 GRAVEL FILTER 100% HOUSE/DRIVE 0.00 ROADS/WALKS 0.87 STRAW/MULCH 0.45 WEIGHTED C-FACTOR 0.03 WEIGHTED P-FACTOR 0.80 EFF 97.84 SILT FENCE E 2.93 SILT FENCE 100% HOUSE/DRIVE 0.00 ROADS/WALKS 0.00 STRAW/MULCH 2.93 WEIGHTED C-FACTOR 0.06 WEIGHTED P-FACTOR 0.80 EFF 95.20 SILT FENCE F 3.50 SILT FENCE 100% HOUSEIDRIVE 0.65 ROADS/WALKS 0.23 STRAW/MULCH 2.62 WEIGHTED C-FACTOR 0.05 WEIGHTED P-FACTOR ' 0.50 EFF 97.63 XA908200\QPWIEFFECT. WB2 PAGE 2 OF 3 1 1 1 1 1 1 JR Engineering, Ltd. 4812 South College Avenue, Fort Collins, Colorado 80525 EFFECTIVENESS CA LCI II.ATIONS GV (970)282-4335 PROJECT: SCENIC VIEWS PUD STANDARD FORM B COMPLETED BY: DWK DATE: 06/27/96 EROSION CONTROL C.FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 1.00 SMOOTH CONDITION ROUGHENED GROUND 1.00 0.90 ROADS/WALKS 0.01 1.00 GRAVEL FILTERS 1.00 0.80 " SILT FENCE 1.00 0.50 STRAW MULCH 0.06 1.00 ESTABLISHED GRASS 0.08 1.00 HOUSE/DRIVE 0.01 1.00 MAJOR PS EROSION CONTROL SUB AREA BASIN (%) DEVICES BASIN (Ac) CALCULATIONS AC UNDISTURBED EX3 6.50 GRAVEL FILTER 0% HOUSE/DRIVE 0.00 ROADSIWALKS 0.00 STRAW/MULCH 0.00 WEIGHTED C-FACTOR 0.00 WEIGHTED P-FACTOR 0.80 EFF 100.00 OVERALL EFFECTIVENESS = 97.84 > 80.9, O.K. n XA9082001QPW1EFFECT. W62 PAGE 3 OF 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 G�S CONSTRUCTION SEQUENCE STANDARD FORM C PROJECT: SCENIC VIEWS PUD SEQUENCE FOR 1996/1997 ONLY COMPLETED BY: DWK DATE: 08/26/96 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. fg9-7 q g MONTH SEPTEMBER OCTOBER I NOVEMBER I DECEMBER JANUARY Demolition Grading Wind Erosion Control: Soil Roughing Perimeter Barrier Additional Barriers Vegetative Methods Soil Sealant Other Rainfall Erosion Control Structural: Sediment Trap/Basin Inlet Filters Straw Barriers Silt Fence Barriers Sand Bags Bare Soil Preparation Contour Furrows Terracing Asphalt/Concrete Paving Other egetative: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting Sod Installation Netfings/MatsBlankets Other 'TOME CONSTRUCTION '1CTURES: INSTALLED BY: rATION/MULCHING CONTRACTOR: IBMITTED: 08/96 CONTRACTOR MAINTAINED BY: DEVELOPER TO BE DETERMINED BY BID APPROVED BY CITY OF FORT COLLINS ON: 1 1 1 1 1 t JR Engineering, Ltd. 4812 South College Avenue, Fort Collins, Colorado 80525 JOB NO. 9082.00 SCENIC VIEWS PUD EROSION CONTROL COST ESTIMATE CK�Put711?il��]:Sil GG (970)282-4335 08/26/96 DWK ITEM DESCRIPTION UNITS I UNIT COST I QUANTITY I TOTAL COST 14 7oo.cd 1 SILT FENCE LF 82.00 2,350 2 GRAVEL CONSTRUCTION ENTRANC EACH $500.00 2 $1,000.00 3 INLET PROTECTION EACH $250.00 5 $1,250.00 4 STRAW BALES LF $3.25 30 $97.50 5 SEDIMENT TRAP EACH $500.00 1 $500.00 6 RESEED/MULCH ACRE $500.00 8.4 $4,200.00 PRELIMINARY COST TOTAL COST WITH CITY RESEEDING COST 17, &Z1.Z5 ITEM DESCRIPTION UNITS I UNIT COST I QUANTITY TOTAL COST 1 RESEEDIMULCH ACRE $500.00 ji 21.1 $10,550.00 OF 150% X:\908200\QPMEROSCOST.WB2 PAGE 1 of 1 ESCROW AMOUNT = -01 7, (c Z.l . Z 5 APPENDIX H EASEMENTS 1] I I GRANT OF DRAINAGE EASEMENT Scott H. and Cynthia Fisher for good and valuable consideration of _ in the form of a promissory note, grant in perputuity a drainage easement across their property located at 2705 Orchard Place, Ft Collins to Solitaire Properties, LLC, their heirs, and assigns. The precise location of the easement will be determined from engineering drawings approved by the the city of Ft Collins upon Final Plat approval of the Solitaire Properties, LLC. parcel to the west Said Prommisory Note shall be redeemed for cash within 30 days after Final Plat approval of the Solitaire Properties, LLC. parcel. H. Pisher Date 2705 Orchard Place Ft Collins, Colorado C4hthla Fisher sDate / 2705 Orchard Place Ft. Collins, Colorado i 6 William B. eio 6ate Manager, Solitaire Properties, LLC. 6645 E. Heritage Place South Englewood, Colorado The above Ignatures_ were acknowledged before me this �Lday of 1996, by ohb, i„ f,• a Colorado Notary. My commission expires . jj:.3 - 98 ' Notary Republic Address 6A •_ln_/�_� t William B Veio's signature was acknowledged before me this loth day of Pli 6, by Sharon L. Camara, a Color do Notar,Y. ° ON �va�i £ Ary�hRd SNARt�_ ,. � Rocky Mountain Research Institute ':ve nu..: •a. Ifi APPENDIX 1 DITCH COMPANY AGREEMENT 1 [J 11 S / . CROSSING AGREEMENT THIS AGREEMENT, made this loth day of March ' 19 81 , between the Pleasant Valley and Lake Canal Company, hereinafter the "Company," and Scenic views, Inc. hereinafter Scenic Views, Inc. , WITNESSETH: ' THAT WHEREAS, the Company is the owner of an irrigation ditch and right of way, commonly known as the ' Pleasant Valley and Lake Canal; and WHEREAS, Scenic Views. Inc desires to acquire ' a certain right of way to cross the irrigation ditch of the Company either by going over or under that ditch. ' NOW, THEREFORE, in consideration of One Hundred Fifty Dollars ($150.00 ), the receipt of which ' is hereby acknowledged by the Company, the parties mutually agree as follows: 1. The Company grants to Scenic Views, Inc. a right of way and easement to construct and maintain a structure over or under the ditch owned by the Company in Larimer County, Colorado, at the location designated on the ' map attached hereto. 2. The Company grants to Scenic Views, Inc. ' the right of ingress and egress to and from this right of way, as necessary and reasonable for the exercise of the ' purpose of this right of way. 3. If the structure is to go under the ditch, the structure top shall be buried not less than 30 inches below the; -"bottom of the irrigation ditch, and any trench or other excavation in connection therewith is to be backfilled, compacted and stabilized to the entire satisfaction of the ' Company. Retaining walls as the Company might deem necessary shall be installed. , t.4. If the structure is a bridge to go over the ditch, there shall be a four foot clearance from the bottom ' of the bridge to the bottom of the ditch; footings shall be 30 inches cement with wing walls on both ends. Length of the bridge may vary with the width of the ditch at the point ' of crossing. ' ' .. 5. All work shall be performed only after prior notice to the superintendent of the Company, and will be performed under the supervision of such superintendent or by an engineer selected by the Company. If an engineer is retained, his fees and expenses shall be paid by n1r V1PWq 6. In the event any sum is expended by the . Company for repair or maintenance of the ditch at the point of disturbance, Scenic views, Inc. shall reimburse ' the Company for such expense. Determination of whether repair or maintenance is necessary, and whether an emergency exists, shall be the sole right and privilege of the Company. 7. Installation and maintenance of the structure ' shall be entirely without disturbance of the flow of water in the Company's ditch, unless permission in writing is first received from the Company for such disturbance. - Scenic Views, Inc. expressly agrees that it shall ' be liable to the Company or its shareholders in damages for any unauthorized disturbance of the flow of water through. ' the ditch. 8. In the event that the Company finds it necessary ' to perform emergency repairs to the disturbed portion of the ditchbank, either now or at any future time, the Company ' shall be wholly without liability for damages to. Scenic Views, Inc. as the result of the performance ' of said repairs, except as to such damage as may be caused by gross negligence or wanton and willful misconduct. �'3 ' 9. Installation of the structure shall be entirely without cost to the Company. The Company's attorneys shall be directed to prepare this Crossing Agreement, and ' their fees _and -expenses shall be paid by Scenic Views, Inc. Scenic Views, Inc. ' shall indemnify the Company and forever hold it harmless from liability for damage to third persons resulting from ' this crossing or any construction or repair in connection with the crossing. ' 10. The Company shall have full power to operate, maintain, alter, enlarge, relocate, clean and manage its ' ditch as if this agreement had not been made, and any expense or damages caused thereby to Scenic Views,,Inc. ' shall not be chargeable to the Company. In the event, however, that any such action on the part of the Company tcould reasonably be expected to effect the storm sewer the Company agrees to give prior notice to City of Fort Collins and to cooperate with City of Fort Collins to avoid injuries or damage to that line. -' 11. This Agreement and all the terms and conditions thereof shall extend to and be binding upon the successors ' and assigns.of each of the parties hereto, including, but not limited to the City of Fort Collins should it become a successor of Scenic Views, Inc. , by Deed of Dedication or by any other means. Upon transfer of its ' interest in this Crossing Agreement, Scenic Views, Inc. agrees to inform the Company of the name of the transferee. IN WITNESS WHEREOF, the parties hereto have caused ' these presents to be duly executed by the proper officers, and have affixed their seals hereto on the day and year ' first above written. 11 u [1 3 - 1 1 1 1 1 PLEASANT VALLEY & LAKE CANAL COMPANY ATTEST: '.:Secre ar - y Y President ATTEST: By • rbtxp���, _) By: Secretary Donald W. Marostica Albert S. Paone, President J 's sy I 1 I ' APPENDIX J RETENTION POND ELEVATION -STORAGE DURATION CURVES ' WATER QUALITY VOLUME 1 1 t 1 1 `1l CALCULATING ACTUAL DETENTION POND VOLUME USING CONE FRUSTRUM FORMULA: IOLUME= 1/3'h(A1+A2+SQRT(A1'A2)) ' WHERE: Al AND A2 ARE THE AREA OF THE BASES 1 1 1 t 1 1 FT SF CF CF AC -FT 5098.0 8,126 0 0.0000 1.0 9,126 5099.0 10,165 9,126 0.2095 1.0 11,204 5100.0 12,277 20,331 0.4667 1.0 13,418 5101.0 14,592 33,749 0.7748 1.0 20,756 5102.0 27,606 54,505 11513 1.0 32,910 5103.0 38,516 87,415 2.0068 1.0 40,210 5104.0 41,928 127,625 2.9299 1.0 43,684 5105.0 45,464 171,309 3.9327 1.0 47,275 5106.0 49,109 218,584 5.0180 1.0 50,976 5107.0 52,866 269,560 6.1882 1.0 54,791 5108.0 56,738 324,350 7.4461 1.0 58,720 5109.0 60,725 383,070 8.7941 1.0 62,764 5110.0 64,825 445,834 10.2349 1.0 66,921 5111.0 69,040 512,756 11.7713 1.0 71,191 5112.0 73,364 583,947 13.4056 0.5 37,232 5112.5 75,571 621,179 14.2603 JOB # 3676.00 DATE 01/22/97 BY: BKW I mr.d I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 JREngineering, Ltd. 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L — ry d 9 O O d N M y ; d 0 O L 0 O 'O >— W L . > v T` `o E �n �n N e D y> C 0; !� a a c 10 c a E E T o E �n h N N D> a C L Q C= 3 .n n d a a c t0 c n L E E o rM 6o o o oo c 0 26 2 E nJ'-' d o �`0�vic0000 o0 c Q 2L6 2 E a ' �+Z�aN Q o0 .2a dNdao o.� �+ZU ct9E-= a ¢ aN o9 dN dcv nm a"E19 m- m a� _ M r6 Ea c d c J C 0- U Oni On C L N O lV 10 10 l0 {O Ea c w c 5 c d 'gyp U U m 0 0 0 L N d O O O N N Y W Y}} N N _ N N N N 6 q O O 4 L N d U n,,C dC O 0 0 d i d T d Y d Y d Y E 0 N N 10 am 00 t d O A ' C 6 LL W d U O O} N i0 O i0�O E L L L r L N C Q d U D O N �1 d N 0 E L L L L N J F �- �O 1- 0 OOCi ""DOO r N N J ' JAN-24-97 FRI 16:09 F1 [1 11 DEPT OF ATNO SCIENCE FAX NO. 970 491 8449 P. 02 Monthly Climatic Data for FORT COLLINS for years 1948 - 1995 Station - 53005 latitude - 4035 Longitude - 10505 Elevation - 5000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dee Annual Total monthly precipitation. Ave 0.42 0.41 1.26 1.72 2.79 2.07 1.65 1.39 1.17 1.00 0.70 0.46 14.93 Max 1.17 1.2& 5.63 4.42 7.47 6.31 5.86 7.39 4.00 4.85 2.29 1.52 28.42 Year 1962 1987 1990 1971 1995 1949 1977 1951 1961 1969 1973 1979 1961 Min 0.01 0.00 0.01 0.22 0.01 0.08 0.13 0.03 0.02 0.05 0.00 0.00 7.34 Year 1983 1992 1966 1955 1974 1980 1963 1960 1"2 1956 1965+ 1959+ 1966 Count 48 48 48 48 48 48 48 48 48 48 48 47 47 Total monthly snowfall. Ave 7.7 6.5 12.3 6.6. 1.1 0.0 0.0 0.0 0.8 3.0 8.1 7.4 53.8 Max 19.3 16.7 39.6 27.5 27.8 0.2 0.0 0.0 15.0 14.7 29.1 20.7 107.2 Year 1960 1989 1988 1957 1978 1955 1995+ 1995+ 1971 1969 1979 1979 1979 Min 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 26.4 Year 1983+ 1992+ 1966 1992+ 1995+ 1995+ 1995+ 1995+ 1994+ 1992+ 1965+ 1959+ 1974 Count 48 48 47 48 48 48 48 48 48 46 48 47 44 Number of days with >= 0.1 inches precipitation. t,-rea + of - Ave 1.9 1.7 4.0 4.4 6.1 4.8 4.4 3.9 3.2 2.8 2.6 1.7 41.6 Max 9 7 11 10 17 16 16 14 10 9 8 8 110 Year 1948 1948 1951 1953+ 1995 1951 1950 1951 1950 1949 1952 1951 1951 Min 0 0 0 1 0 0 0 0 0 0 0 0 21 Year 1995+ 1992+ 1966 1990+ 1974 1980+ 1963 1060 1992+ 1988+ 1988+ 1991+ 1977 Count 48 48 48 48 48 48 48 48 48 47 48 47 46 Li17/7,,, Adky . okl4wx. y, 4410. dd5 �iil�rel�lCes Cato b� � �.c.Tl'U CLfD-Q•�c7 � � (7,l '� �7�c �2R r10� ' JS JAN-24-97 FRI 16:10 DEPT OF ATMO SCIENCE FAX NO. 970 491 8449 P.03 Monthly Precipitation Surmary for FORT COLLINS 53005 ' Lot 4035 Long 10505 Elev 5000 Mean JanMar May Jun Jut Avg Sep Oct Nov Dec 0,43 0.9 1.28 1.771 ' Max 2.83 2.11 1.61 1.37r 1.18 0,98 0.70 0.45 1.17 1.28 5.63 4.42 7.47 Year 6.31 5.86 7.39 4,07 4.84 2.29 1.52 1962 1987 IWO 1971 1995 1949 1977, 195, 1982 1969 1973 1979 Min Year 0.02 0.00 . 0.01 0.22 0.01 0.08 0.13 0.03 0.02 0.05 0.00 0.00 1983 1992 - 1966 1955 ' 1974 1980 1963 1960 1992 1956 1965 1959 Count 49 49 49 49 49 49 49 49 49 49 49 49 Prob Precipitati on with Probability Equal or Less Than 0.05 don Feb Mar Apr mayJunJut Aug Sep Oct Nov Dec 0.07 0.01 0.13 0,49 0.10 0.44 0.30 0.36 0..15 0.08 0.09 0.01 0.00 0.10 0.04 0.23 0.66 0.20 0.68 0.47 0.51 0.26 0.16 0.15 0.04 0.01 0.17 0.09 0.40 0.90 1:09 0.77 0.74 0.45 0.31 0.28 0.15 0.06 ' 0.40 0.29 0.21 0.77 1.32 1.89 1.37 1.17 0.50 0.84 0.65 0.57 0.38 0.20 0.35 0.28 0.99 1.54 2.33 1.71 1.40 0.60 1.07 0.86 0.74 0.50 0.29 0.43 0.37 1.24 1.78 2.84 2.10 1.65 1.34 1.12 0.94 0.65 0.39 0.80 0.90 0.65 0.62 1.99 2.42 4.29 3.23 2.36 2.13 1.88 1.55 1.09 0.70 0.86 0.86 0.95 2.70 3.00 5.64 4.28 3.00 2.88 2.63 2.14 1.51 1.01 1.05 1.11 3.40 3.53 6.93 5.30 3.61 3.61 3.37 2.72 1.92 1.31 Number of Days with Precipitation Equal To or Greater Than Cy,f'le e. nt.f-e Jan Feb w Mar Apr May Jun .ful Aug Sep Oc[ Nov Threshold = 0.01-1 Dec Mean Max 4.63 4.73 7.00 8.02 10.73 9.12 9.29 9.06 6.57 5.06 4.88 4.20 ' Year Min 17 15 21 20 18 15 12 12 11 1957 1987 1990 1995 1995 1967 1950 1963 1982 1993 1983 1967 1 0 1 2 1 2 Year 4 1 1 1 0 0 1983 1992 1966 1955 1974 1980 1989 1974 1956 1977 1965 1959 Threshold = 0.05,, ' Mean Max 2.59 2 .49 4.73 5.39 7.49 5.73 5.55 4.73 4.18 3.41 3.18 2.37 7 6 Year 11 11 20 13 10 11 9 1985 1987 1970 1958 19,95 1995 1968 1979 10 9 8 1996 ' Min Year 1969 1983 1967 0 0 0 1 g 1983 1992 1966 1982 1974 1981 1963 1960 1992 1964 1984 1996 Threshold 0.10., Mean Max 1.47 1.2Z 3.35 4.00 5.47 4.18 3.73 3.20 2.94 2.55 2.29 1.37 5 4 ' Year 8 9 17 12 7 8 8 8 7 5 1980 1995 1970 1958 1995 1967 1973 1979 1982 1959 Min 1983 1967 O O O 1 0 O 0 Year 0 O 0 0 0 1995 1996 1966 1990 1974 1980 1963 1960 1992 1988 1988 1996 ' Mean Threshold = 0.201, 0.53 Max 0.63 1.78 2.53 3.61 2.82 2.33 1.88 2.02 1.45 1.24 0.63 2 Year Min 2 b 6 10 7 5 7 7 6 4 3 1996 1995 1990 1971 1995 1982 1985 1957 1995 1969 1992 1988 0 0 0 0 0 0 0 0 Year 0 0 0 1995 1996 1995 0 1955 1974 1981 1971 1996 1994 1995 1994 1996 Threshold 0.50-1 Mean Max 0,06 0.04 0.61 1.02 1.61 1.24 0.75 0.61 0.67 0,67 0.24 0. 10 1 ' Year Min 4 t 3 5 5 3 3 5 4 1981 1993 1992 1971 1957 1982 1949 1979 1961 1969 1973 1988 0 Year 0 0 0 0 0 0 0 1996 1996 1995 1996 1993 1996 1996 1996 1996 1996 1996 1996 ' Threshold = 1.00a Mean 0.00 0.00 0.12 0.29 0.73 0.35 0.22 0.16 0,08 0. 12 0.02 0.02 Max 0 0 1 3 2 2 Year 1996 1996 1996 1983 3 1 2 1 1 1978 1982 1961 1951 1993 1969 ' Min 0 0 1979 1985 Year 1996 1996 1995 1996 1994 1996 1996 1996 1996 1996 1996 1996 I 'J 1 1 1 i 1 1 1 1 1 1 i 1 1 1 1 APPENDIX K STORMWATER QUALITY AND MANAGEMENT CONTROL PLAN (PREPARED BY ROCKY MOUNTAIN RESEARCH INSTITUTE) Ll K-L 1 1 1 1 1 1 STORMWATER QUALITY AND MANAGEMENT CONTROL PLAN Prepared for Scenic Views, 2nd Replat City of Ft. Collins Stormwater Utility rocky mountain research institute 6 5. ro..cye Dace se - erp.e . 90' 1 - - 303-721�9O I.. 303-721-02a5 . .- . 9 3�3 8-<8n0 marketing. real estate and economic C ultants FINAL SUBMITTAL February 5, 7 997 i Rocky Mountain Research Institute K Z_ 1 1 11 1 RMRI rocky mountain research institute -,,rket ^g. real esrare and eoa-or,•ic cordh. enCs 6645 a herRage deco = = enp� m 901 11 = 303-721-905n DATE February 5, 1997 TO- City of Ft.Collins Planning Staff and STORMWATER UTILITY FROM: Bill Veio, Manager SOLITAIRE PROPERTIES,LLC RE: OUTLINE OF OUR RESPONSES TO THE DEVELOPMENT ISSUES RAISED AT THE PAST P & Z MEETING, DECEMBER 16, 1997 After reviewing the video tape of the December 16 meeting and after hearing Staff's concern in our phone conversation this January, we have prepared this outline of the development issues we intend to resolve. The issues are these: 1. Rainfall, Runoff, and Pond Depth 1.1 Rainfall and Runoff Patterns 1.2 The Groundwater Table Impact 2. The Functional Differences between the Detention vs. Retention Pond 2.1 Detention, Extended Detention, and Retention Ponds 2.2 Water Levels, Frequency, Open Space Use 2.3 Wetlands Transfer 2.4 Stormwater Quality & Best Management Practices 2.5 Overall Detention Pond Appearance, Dry -Wet Areas, Depth to Bottoms 2.6 Summary of The Detention Pond Benefits 3. Exhibits to Clarify Detention, Water Quality, and Open Space 3.1 Water Table Profile Pond Area —As Detention Pond -As Retention Pond 3.2 Pond Area in Plan View —As Detention —As Retention Pond 3.3 Rendering Showing Pond Functioning with Best Management Practices Identified The following text is for your technical benefit and study. After reviewing the text, we would like a meeting to discuss your comments and suggestions. The outline addresses what we believe from an engineering, legal, and water quality perspective meets or exceeds the City of Ft. Collins requirements for development approval. We would like to have your support for the Stormwater Quality plan before scheduling a meeting with the neighboring property owners. ' innovative ideas for industry since 1972 K3 L 1 1 1 [1 11 1] 1. RAINFALL, RUNOFF, AND POND DEPTH 1.1 Rainfall and Runoff data for the site show that 57% of the annual storms will create practically NO RUNOFF producing events. These are storms with rainfall from .0 to 0.1 inch. About 34% of the storms will have rainfall depths from .10 to .50 inches. These two categories of storms represent 91 % of the annual storms which will impact the site and can be handled readily with only minor water depths in the retention pond. The average depth would be 0" in the pond for a Storm of up to .5' if we were retaining only site -generated runoff. With the pond designed to retain the off -site flows from the CSU Equestrian Center and areas north of the site, the pond depth would rise to 21" for a storm up to 0.5". Pond Depth refers to the area of the Pond which is above the wetlands water quality control volume, which is graded a few feet below the overall pond. The Pond would be DRY for resident use as Open Space, 971/o of time, if we were retaining solely on -site generated runoff. By increasing the capacity of the pond to retain all off -site flows from the CSU facility and the area north of the site, the pond will be dry 85% of the time during the year. Please refer to Table 1 and 2 on the following page for these explanations. XA8(E1 %iC7MgBttOFItAiNfALt FYI -.All, tt41G(hts taltIlvl> )t COUNiYdItLrA gr n1a ?> 114u'ACT Ol�i &CENIG VIEWS 1'gNt3 (�1�SlTE AiiA"1NAGE � $V PROPLR3Yj "`� � `" ' ta(rtFail "; Avg�'rty � % i Comm � Pond lime to � �.Avg'CiOrte Depth Ato of %• S?epth Pwap to xPortd:Wet Time (inched Days ;; (laeites) @300$pm PuStnrm k'ond Wet 0.0 to 0.1 47.5 57.1 57.1 0.0 0.0 0.0 0.0 0.1 to 0.5 28.1 33.8 90.9 0.0 1.5 0.0 0.0 0.5101.0 5.5 6.6 97.5 12.0 8.4 32.4 278.2 1.0 to 2.0 1.9 23 98.8 312 222 462 87.8 2.0+ 0.23 028 100.0 (Figures included by type of storm below) Total Ydy: 83.2 200.0 200.0 2-Yr 0.5 20.4 14.1 38.1 19.1 5-Yr 02 38.4 282 522 10.4 10-Yr 0.1 48.0 36.9 60.9 6.1 25.Yr 0.04 622 50.0 74.0 3.0 300-Yr 0.01 81.6 71.7 95.7 1A Total Avenge Time Period Pond is Wet Per Year (Hours): 305.5 Rocky Mountain Research Institute 11 2 t<q 11 J 1 1 The rainfall data is from the Climate Control Center in Ft. Collins. Depth and Pumping Rates, and Wet Time Hours are from the jR Engineering spreadsheets submitted with the Utility Plans. The city SWMM for this basin was used to determine runoff volumes which led to the water level depths above the wetlands pond. Please refer to the Utility drawings for any additional details needed. ofmg e & a �Y.y�J" �� �... F n:...w C�'....� �4:k��'a.?iia� b. ; u � :: '+„Rb.".,.,.. >?�. �.:X+, OA to 0.1 47.5 57.1 57.1 0.0 OA 0.0 0.0 0.1 to 0.5 28.1 33.8 1 90.9 21.2 1 7.0 31.0 869.7 OS to 1.0 5.5 6.6 97.5 27.5 192 432 237.7 lA to 2.0 1.9 2.3 98.8 54.7 43.9 67.9 129.0 2A+ 023 028 100.0 (Figures included by type of storm below) Total Yriy: 83.2 100.0 100.0 2-Yr OS 36.0 26.1 50.1 25.0 5-Yr 02 66.0 55.4 79.4 15.9 10-Yr 0.1 82.6 73.9 97.9 9.8 25-Yr 0.04 103.E 99.9 223.9 5.0 300-Yr 0.01 130.6 237.9 261.9 lb Total Avenge Time Period Pond is Wet Per Year (Hours): 1,293.7 1.2 The Groundwater Table Impact The groundwater level for the retention pond will be reduced using a cutoff trench around the pond perimeter with non -permeable clay soils. After excavation of the pond, any groundwater left in the soil, should dry up to create a dry pond, except for the water quality portion of the pond wetlands area. Rocky Mountain Research Institute L7 3 K6 2. FUNCTIONAL BETWEEN THE DETENTION & RETENTION POND 2.1. Definition of Detention, Extended Detention, and Retention Ponds A detention pond holds runoff and may be releasing runoff simultaneously at the 2-yr historic rate. The primary function of a detention or retention pond is moderating flood flows. An added benefit is their ability to provide water quality enhancement. An extended detention pond is designed to totally empty after runoff ends. The extended pond extends the emptying time of the more frequent storms to facilitate pollutant removal and does so with a smaller outlet. A drain time of the brim -full capture volume of 40 hours is recommended to remove a significant portion of fine particulate pollutants found in urban stormwater runoff. Soluble pollutant removal is enhanced by providing a small wetland marsh or ponding area in the basin's bottom to promote biological uptake. The basins or ponds are considered DRY because they are designed not to have a significant permanent pool of water. A retention pond has a permanent pool of water with a base flow to flush the permanent pond, that is replaced with stormwater, in part or in total, during storm runoff events. Temporary detention is provided above the permanent pool to allow more sedimentation. Retention ponds are similar to extended basins because they are designed to capture in total, and detain a volume of runoff from frequently occurring storms. Retention ponds differ from extended detention basins because the runoff water mixes with the permanent pool water as it rises above the permanent pool. The water quality capture volume above the permanent pond is released over 40 hours, the same as for an extended detention basin. The 40-hr discharge period allows the sediment removal process to be more efficient when the outflow occurs above the bottom of the basin. (See Utility Plan pond profile) Sediments become trapped below the outlet and sedimentation continues in the pool after the captured surcharge volume is emptied. Retention ponds are very effective in removing pollutants. They are used to improve the quality of urban runoff from roads, parking lots, residential neighborhoods, commercial areas, and industrial sites. They are generally used as regional or follow- up treatment ponds. Determination of the classification of the Scenic View basin as a retention pond or as an extended detention pond is determined by the pond outlet elevation, the rainfall - runoff data, the groundwater elevation, and the volume storage capacity. 2.2. Pond Water Levels for 2-Yr, 5-Yr, 10-Yr, and 100-Yr Storm Events and Impact on Open Space Use In a typical year the amount of runoff that needs to be detained can be estimated by examining the mean inches of rainfall and storm frequency by month. Tables I and 2 contain the estimated amount of annual rainfall for the site. Table 3 shows the seasonality of rainfall for the site. In general, 0.1 inches of rainfall depth is the amount necessary to cause runoff. On average, about 35 storm events occur each year that are equal to or greater than 0.1 inches in precipitation depth. HocKy mounraln ne5earcn InSnrule 4 r I<& 1 11 LJ 1 F1 ya�� p„HMO,NTtitY`3'>�eKtril'fA't�t)l��Sif�ltM'�t�l!j�Y ������y ::�.,vyy%Nyayys�:. �4`?'S I. C S'_..5:�{ v"'�4Sye,.',.�^':„w\N:Y 5 "�tY ...... I �.....x January 0.42 7.7 L47 4A 86 February 0.41 6.5 L22 3.7 87 March 2.26 223 3.35 20.0 68 April L72 6.6 4.00 12.0 60 May 279 Ll 5.47 16.4 47 June 2.07 0 4.18 12.5 58 July 1.65 0 3.73 112 64 August 1.39 0 3.20 9.6 69 September 1.17 0.8 2.94 8.8 74 October 1.00 3.0 2.5S 7.6 75 November 0.70 8.1 229 6.9 1 78 December 0.46 7.4 L37 4.2 87 By reviewing the Mean Number of Storm Days each month in Table 3, it is easy to estimate how much of the time the retention area will be in use as a storm runoff collector and how much of the time the area will be useable as open space for residents. In the months of December, January, and February only ONE STORM a month is expected to occur which will cause runoff... leaving an average of 25 days a month of active open space for residents. During the months of September, October, and November TWO STORMS are expected to occur which could produce runoff ...leaving an average of 22+ days a month for recreation. In the months of March, April, June, and August THREE STORMS a month are expected to produce runoff... leaving 18+ days a month for resident open space use. In May and July as many as FOUR STORMS a month could produce runoff... leaving 15+ days for open space use by residents. Based upon typical rainfall patterns for the area, the site would be available for active open space use 258 days out of the year (71% of the time), or an average of 21+ days per month per year. NOTE. These estimates are very conservative and assume it will take 2 full days to drain the retention pond for each storm which exceeds 0.1 inch of rainfall. From Tables 1 and 2 it is clear that for 80% of the storms which produce 0.1 inch of rainfall or more, the pond can be pumped within 7 hours time, if desired Thus, the estimate of DRY days usable as Open Space shown above is the MINIMUM TIME estimate. Rocky Mountain Research Institute Wi I K7 1 1 1 1 1 1 1 1 LJ 1 1 1 1 1 1 2.3 Wetlands Transfer There is an existing area of about 8,000 sq.ft. near the northwest property boundary which is a wetlands created accidentally when the CSU Detention Pond and City water lines were installed in Overland Trail in 1988. This wetlands is too small to qualify for U.S. Corp of Engineer regulations, but will be relocated to the Detention Pond area to enhance stormwater quality and to create a visual amenity for residents. 2.4 Stormwater Quality and Best Management Practices 2.4.1 Existing Stormwater Quality --Prior to Development a. The existing storm runoff now contains fertilizers and pesticides used to grow alfalfa, plus wastewater and stream particulates from the CSU Veterinary School and Equine Center. In storm conditions these particulates are deposited into the canal. b. In periods of storm runoff, particulates from the horse pastures to the north of the Scenic Views site enter the canal. c. According to the ditch company representative, it is a common occurrence to have illegal dumping of oil, trash, and organic materials into the canal. d. Under present conditions, the canal water quality is poor quality due to runoff for up to 24 hours after a storm,. The canal representative has advised the Happy Heart Farm and other water users "NOT TO USE the canal water for irrigation purposes within 24 hours of a storm because of its poor quality during storm events." After 24 hours the sediment will settle out in the canal bottom, and the water quality vastly improves for irrigation. e. The irrigation canal water is NOT for human consumption. The ditch company has NO WATER QUALITY delivery standards or criteria to meet or to guarantee for any of its users. Users of the irrigation ditch take whatever water is in the ditch and use it for irrigation purposes. They have operated this way for many generations without service disruption or dissatisfied customers. g. The irrigation company sees the creation of a retention pond as an effective tool for limiting peak flows, which could also improve the stormwater quality which would flow overland into the ditch. They also recognize there would be less risk of overtopping of the ditch due to flooding. They are also aware that detaining the stormnmoff would cause less damage to the ditch embankments, and would result in greater effective use of the ditch capacity in flood periods. They also recognize the detention basin would reduce the historic flow of stormrunoff into the ditch. ROCKY Mountain Hesearcn institute 0 K9 .1 I I I I I� I J t [1 I h. The irrigation company is willing to allow the discharge into the ditch after peak flow periods of a storm, because of the benefits cited above. 2.4.2 Stormwater Quality with Development —Best Management Practices Urban stormwater runoff contains a variety of constituents that originate from a number of different sources. To reduce the concentrations and the loads that would reach the irrigation canal or other receiving waters, Best Management Practices (BMPs) have been suggested by EPA, other Federal and State Agencies, and professionals who deal with stormwater. There are two categories of BMPs, both of which will be utilized in improving stormwater quality at Scenic Views: Non -Structural BMPs include pollution prevention and source control BMPs. Structural BMPs include facilities constructed to passively treat stormwater runoff before it enters the canal or other receiving waters. Advantages of Non -Structural BMPs Non-structural BMPs prevent or limit the entry of pollutants into stormwater at their source. Prevention is desirable and can be cost effective because it avoids pollution in the first place and thereby reduces the amounts that need to be removed by subsequent treatment. The advantages of Non -Structural BMPs are: " The quality of stormwater runoff is improved ' The volume of sediment, debris, and other pollutants deposited in receiving waters is reduced The operation and maintenance of structural controls is reduced " There are benefits to air quality, ground water quality, and waste control ' Open space and wildlife habitat is enhanced ' Public awareness of water quality, problems is heightened and personal involvement in solutions happens " Public awareness of stormwater quality issues increases ' Most require only a modification of existing practices, are simple to understand, and make good sense ' Implementation can occur rapidly Rocky Mountain Research Institute 7 I K9 I I I I L I I I i I I 1 I Non -Structural BMPs Used at Scenic Views The following Best Management Practices are being employed for the Scenic Views development: 1. Preparation of this Stone Water Quality Control Plan which states water quality control objectives, the description of stormwater quality management practices, contains exhibits and drawings showing the structural BMPs, the hydrological and hydraulic calculations documenting sizing and stability of drainage features, and descriptions of maintenance responsibilities and access. 2. Preparation of an Erosion Control Plan This Plan is a part of the Final Drainage Plan and Utility drawings which have been submitted to city staff. The objective of the Plan is to mitigate the potential for soil erosion and to control sediment movement during the construction process until final landscaping and stormwater quality measures are effectively in place. 3. Proper Disposal of Household Waste and Toxins The developer and the Homeowners Association will create a resident and visitor information program that teaches the proper disposal of household waste, litter, pet waste, yard waste, used oil, and toxic waste. Facilities for proper disposal will be provided throughout the development. Neighborhood newsletters, HOA monthly billing inserts, recreation center bulletin boards, the HOA covenants, and periodic HOA meetings will reinforce these policies. Proper disposal of household waste and toxics can reduce the deposition of solids, organics, nutrients, oxygen -demanding substances, solvents, caustics, paints, automotive fluids, toxic substances and fecal material on the land and reduce their presence in the stormwater reaching receiving waters. Improper disposal of used oil and automotive Fluids causes receiving waters to be contaminated with hydrocarbons and residual metals that can be toxic to stream organisms. Used oil and other petroleum products can be recycled. Information on the location of recycling centers, the benefits of recycling, prevention of fluid leaks, and the importance of proper disposal for improving stormwater quality can reduce the amount of oil and used automobile fluid reaching receiving waters. Through an on -site communication program residents and visitors will be alerted about their everyday use of toxic wastes: paint, solvents, putties, cleaners, waxes, polishes, oil products, aerosols, adds, caustics, pesticides, herbicides, and certain medicines or cosmetics. Seminars will present non -toxic, safe, biodegradable product alternatives and discuss proper disposal points within the community. n ROCKY mounrain Mesearcn lnsnnlle I I{/o I i 1 I F L 1 I I 1 i 1 I 1 Other on -site actions that will be taken to improve resident and visitor awareness and personal responsibility for stormwater quality: • Distribution of the Irrigation Ditches brochure in the rec center, sales offices, and on the bike and walking paths along the canal • DON'T LITTER signs in open space and along canal • Neighborhood clean-up day for parks, bike paths, open areas ' Pet Waste disposal bag containers along paths and park areas • Waste containers distributed throughout the open spaces and walks 4. Guidelines for Proper Use of Pesticides, Herbicides, and Fertilizers Pesticides, herbicides, and fertilizers are chemicals used in landscape maintenance. Pesticides are used for insect control, herbicides for weed control, while fertilizers are used for the growth and greening of grass. Pesticides and herbicides are toxic to aquatic life at low concentration, and fertilizers can be toxic at high concentrations. Fertilizers tend to promote algae growth which can deplete dissolved oxygen for fish and other aquatic organisms. The rate and timing of the use of pesticides, herbicides, and fertilizers are important to minimize potential transport by stormwater runoff. Overapplication and overspraying onto impervious areas needs to be avoided as well as too frequent or excessive use. Following manufacturer's recommendations can prevent most of the surface water contamination being attributed to their use. With the HOA'in control of all open space applications, manufacturer's specifications can be followed. S. Illicit Discharge Controls Educating residents and visitors about illegal dumping practices, about the potential hazards to public health and the environment, and encouraging the immediate reporting of spills can create a citizen sensitivity to deter illicit dumping. Controlling public automobile access to the neighborhood would go a long way to prevent the dumping of trash, refuse, and fluids or toxic substances into the canal. Controlled access to the neighborhood was part of the original design to presented to the city planning staff, but was refused "as an undesirable neighborhood element". 6. Landscaping and Vegetation Practices Soil erosion and transport from urban areas produces only a fraction of total sediment arriving at streams and waterways. Agricultural HOCKy mountain r7C56d1L;f1111.2111U O 1 �j I( 1 L I 1 I I J 1J I 11 activities by far exceed the quantities from urban areas. Establishing and maintaining landscaping and vegetation in existing urban areas can assist in reducing stormwater runoff rates and volumes, sediment loads, and pollutants associated with sediment from entering streams and lakes. Vegetation acts to reduce raindrop impact on soil, slows runoff rates, and encourages infiltration of precipitation into the soil. Pollutants, such as metals, nutrients, and bacteria that are attached to sediment will also be removed. The overall volume of runoff from a vegetated area is less than from an area of bare soil. Although bare soil will also allow some infiltration, its surface has a tendency to seal and erode. The eroded soils are a source of sediment transport to the receiving waterway. The landscape plan for the site contains over 100 trees, bushes, shrubs, and several acres of grass vegetation. The landscaping and vegetation will reduce the sediment load from existing conditions and enhance stormwater quality. Maintenance of the planted areas will be the responsibility of the HOA. Advantages of Structural BMPs Reduced runoff, particulate removal, and some measure of flood control are the principal benefits of Structural BMPs. Pollutants are removed by adsorption, settling, precipitation, infiltration, filtration, and biological activity. The advantages are: Enhanced stormwater runoff quality • Can reduce runoff volumes through infiltration and interception Can reduce peak rates of runoff, especially for smaller storms, by capturing and slowly releasing urban runoff " Can be constructed first and then used to control erosion and sedimentation during site construction Can be combined with other municipal or public uses such as active and passive recreation, open space, and wildlife habitat Can sometimes integrate BMPs into site landscaping to supplement irrigation of vegetation Can be combined with drainage and flood control objectives at incremental costs to minimize and control downstream flooding Rocky Mountain Research Institute I 10 .1 /<IZ .1 1 1 1 7L r I 1 1 1 1 1 I 1 1 Structural BMPs to be Used at Scenic Views The following Best Management Practices are being employed for the Scenic Views development: 1-2 Irrigated Grass Buffer Strips and Grass -Lined Swales. Adjacent to all buildings and parking areas are large patches of grass to which roof top drains will direct storm runoff. Passing through the grass and vegetation slows the storm runoff peak and promotes pollutant fallout prior to the water entering the stormwater drains. Grass lines swales direct stormwater flow, contribute to lowering the peak flow, and reduce pollutant loads into the stormwater basin. A swale will occur in the detention pond bottom to direct water flow to the wetlands. This wetlands bottom channel will be gravel lined and filter particulates. NOTE: Healthy grass can generally be maintained without using fertilizers because runoff from lawns and other areas contain the needed nutrients. Periodic inspection is needed in the first few years to identify any problems areas and to plan for long-term restorative maintenance. 3. Water Quality Extended Detention Basin (Dry Basin) Extended detention basins are designed to drain their brim -full volume in about 40 hours through a perforated riser pipe to remove a significant portion of the particulate pollutants found in the stormwater runoff. Soluble pollutant removal is enhanced by providing the small wetland marsh or ponding area in the basin's bottom to promote biological uptake. The basin is considered dry because it is designed not to have a large permanent pool of water. The flood detention volume is provided above the water quality capture volume (WQCV)"of the basin. No more than 50% of the WQCV will be released in 12 hours. The extended detention basin reduces peak runoff flow rates into the canal and prevents periodic flooding of properties downstream while improving water quality and providing recreation and open space opportunities. The basin is effective in removing particulate matter and associated heavy metals and other pollutants. On -Going Monitoring of the Stormwater Outfail The HOA will be responsible for the drainage basin maintenance and will have instructions for using bio-degradable pesticides, debris removal, grass mowing, and wetlands monitoring. The HOA will keep a log of basin grounds maintenance including pumps, recycling pickups, resident attendance at on -site ecological seminars, and use of outdoor litter disposal conveniences. Annually in May, July, August, and September the HOA will monitor pond discharge by water sampling and send results to an independent lab for content analysis. Results will be evaluated by the HOA Board annually to track the effectiveness of the Best Management Practices program. Rocky Mountain Research Institute 11 11 K15 I I I I I I I 7 J I The HOA will check the retention pond pumps prior to the start of the rainy season, and during major storms. In the event of a pump malfunction, possible repairs will be made, and the ditch company and city stormwater department notified, if repairs are unsuccessful, and a storm is occurring or forecasted. 4. Water Quality Retention Pond (Wet Pond) Retention ponds are designed for a 40-hour drain time above the permanent pond because the sedimentation process is more efficient and some mixing and dilution between a permanent dry weather pool and storm runoff occurs. The wet pond also provides for treatment between storms which provides a long period of time for fine particles to settle out and for biological activity to occur. Outflow occurs above the bottom of the basin allowing sediment to be trapped below the outlet with sedimentation continuing after the captured surcharged volume is emptied. A continuing source of water flow is needed to support the permanent pond (WQCV). Refer to Pond Plan in the Utility drawings. S. Constructed Wetlands Wetland basins are designed to drain the water quality capture volume (WQCV) in no less than 24 hours, thereby providing for some biological uptake during the contact with wetland media. The depth of the WQCV is under 2'. The permanent pool area is divided between free water surface area (30% to 50%) which will be 2' to 4' deep ... and the wetland zones with vegetation (50% to 70%) which are typically 6" to 12" deep. A skimmer device is installed on the pond outlet about one-half the depth below the permanent water surface and rises to the maximum capture volume depth. The full WQCV should be above the permanent pool level. Refer to the Landscape Plan and Utility Drawings for the wetlands area design. 6. Sand, Gravel and Other Filters, Skimmer, Perforated Raised Pipe These are other BMPs that work in conjunction with the above Structural BMPs which enhance the stormwater quality before it enters the canal or other waterways. Effectiveness of BMPs Measures Runoff Pollutants can be grouped into two categories: particulate and soluble. Particulates are considered larger than .4 microns in diameter. In many cases, constituents, such as metals and oxygen demand compounds, become adsorbed to particulate matter. If the particulate matter is removed, so are the adsorbed or attached constituents. A combination of the following basic pollutant removal processes is used to remove pollutants at Scenic Views: Sedimentation is the process of particulate matter settling out of stormwater runoff. Smaller particles under 60 microns in size (fine silts and clays) can account for 80% of the metals in stormwater attached or adsorbed with other 12 Pocky mountain Hesearcn ►nsurure K/4 C J I 11 Ld I I contaminants and can require from 12 to 40 hours to settle out of suspension. Extended detention allows smaller particles to agglomerate into larger ones, and for some of the dissolved and liquid state pollutants to adsorb to suspended particles, thus removing a larger portion of them through sedimentation. Filtering. Here particulates are removed from water by filtering. Particles attach to small diameter collectors such as sand, pebbles, or gravel. Infiltration. Pollutant loads in surface runoff are removed or reduced as the water infiltrates or percolates into the ground. Particulates are removed at the ground surface by filtration through the vegetation and soil, while soluble constituents are also adsorbed into the soil, at least in part. Biological Uptake. Plants and microscopic animals require soluble constituents such as nutrients and minerals for growth while are found in stormwater runoff. Soluble constituents are ingested or taken up from the water and concentrated through bacterial action and phytoplankton growth. In some instances plants could be harvested to remove the constituents permanently. In addition, certain biological activities can reduce toxicity of some pollutants and/or possible adverse effects on higher aquatic species. Pollutant Removal Efficiencies Table 4 presents the ranges of pollutant removal efficiencies which are expected using the Structural BMPs with the above processes. VvAl. r zz am1�'�'�'� ��t10�k K C<)NTROLALf6RNA1TYEz �ys�.`�4i �F a'c''aa��.�✓"`�,i�"�h.'ifi'2'a 'u S`dliiis �`z�i N�� ��i �h`��s ,,,y, � " s :,a Grass Buffer Strips .10-20 0-20 0.10 0.30 na. Grass -Lined Swale$ 2040 0.15 0-15 0.20 na Extended Detention Pond 50-70 10-20 10-W 3040 50A0 (Dry) Retention Pond (Wet) 60-95 0-80 0-80 0.70 na. Constructed Wetlands 40.50 10-60 0.20 5040 na JI Source: Observed BMPs reported for Extended Detention and Retention Ponds by Environmental Protection Agency (1983), Grizzard (1982), Whipple and Hunter 0982) and Urban Drainage and flood Control District, Metro Denver (1992). Wetland data from USGS for a8 constituents except Tota6P,, Lakatos and McNemer 0987) for Total-P as reported by Urban Drainage Flood Control District Metro Denver (1992). Rocky Mountain Research Institute 13 J<I,5 I �I I i 1 1 I 1 1 I 1 2.4.3 Conclusions Drawn From Stormwater Quality Management Practices An effective strategy for reducing stormwater pollution loads is to use multiple BMPs, including Non -Structural measures, source controls, and Structural BMPs. These water quality facilities are designed to capture and treat the 80% percentile storm runoff event. Capturing and treating this volume is estimated to remove between 80% and 90% of the annual TSS (total suspended solids) load. Multiple BMPs can provide complementary water quality enhancement to achieve desired results. A multi -level approach deals with many pollutant and runoff sources throughout a watershed and shows that combining most effect BMPs in a series can be an effective strategy to reduce pollutant loads being transferred to receiving waters by stormwater. This is the BMPs Strategy that is being employed for stormwater control and quality enhancement at Scenic Views. 2.5 The Overall Detention Pond Appearance, Dry -Wet Areas, and Depth to Bottoms The Scenic Views Pond could be just as easily be called an Extended Detention Pond as a Retention Pond. With the smaller permanent pond and wetlands being charged by groundwater and periodic stormwater runoff, it is the calculation of the water quality capture volume which determines the more accurate description of the basin. The WQCV computations show a required volume of .42 ac-ft. This translates to a permanent triangular -shaped wetlands pond of about 170'length by 130' width by 3' deep. The remaining volume of 13.8 ac-ft is the DRY portion of the basin which varies in depth from 9' to 12' and will handle 2 times the 100-yr storm. The exhibits specified in Section 3 of the outline are being prepared for the neighbors and the Final Plat hearing. You will receive copies for review when they become available. The purpose of the exhibits is to show how the pond will look in Plan and Profile view; and how the BMPs work together on the site. 2.6 Summary of The Detention Basin Benefits The above storm drainage basin will handle all on -site runoff for the 100-year storm, plus has additional capacity to hold the off -site runoff volume from CSU and the northern flows for the 100-yr storm This excess storage capacity insures enhanced stormwater quality to the downstream users. Of major importance is that Plum Basin downstream property owners and homeowners should never again be flooded in the 5-yr, 10-year, or 100-yr storm event. This basin improvement is estimated to save downstream residents over $2,800,000 in potential flood damages over the next 50 years. 3. Exhibits to Clarify Detention, Water Quality, and Open Space 3.1 Water Table Profile Pond Area —As Detention Pond -As Retention 3.2 Pond Area in Plan View —As Detention —As Retention 3.3 Rendering Showing Pond Functioning with Best Management Practices Identified Rocky Mountain Research Institute i 14 JAN-24-97 FRI 16:11 DEPT OF ATMO SCIENCE FAX NO. 970 491 8449 P.05 t FORT COLLINS -- DRY -DAY PROBABILITIES ' BASED ON 1889 - 1991 DAILY DATA 10 1 1 80 ORO J F M A M J J A S O N D 1 1 IKI-7 JAN-24-97 FRI 16:13 1 1 1 } 1 0 w m y t z z 1 1 � 1 1 1 1 1 DEPT OF ATMO SCIENCE FAX NO. 970 491 8449 MEDIAN LENGTH OF TIME BETWEEN MOISTURE FORT COLLINS, COLORADO 1889. 1991 P. 07 No Text I\----/---� __I__—{11fLJ� L 11 11 I I I _ _ I I I I L�STA MH-STB MH-SV99 STA 3+11.99 STA 5+gI.99 MAGLEA9ELIGOJ / RATE DOCUMENT / / _ _ \ limm � -- — Lr Jw RCP L 15' DRAINACE EASEMENT BY SEPARATE DOCUMENT \ y� _. City of fart Collins. Colorado UTILITY PLAN APPROVAL APPROVED: _ 3;R.1v w DNMNmv CHECKED BY: _ %W ! wslw VUNT \ APPROVED: BY THE PLEASANT VALLEY ! LAKE CANAL CHECKED BY: _ COMPANY THIS�AY Cf 19_• StmnMs a1Mr CHECKED BY: pir _ ARUM PRESIDENT CHECKED BY: _ CHECKED BY: -,-I- —I— _i.,.K,. , i, ...,, h _ --1 230 u 2 CR P CJOS - - TOC3 3e 94.- H-Sl9 TA 9+00.93 I 1 I 1 I - - — - - 50 35 D 50 IN I -- J HORIZONTAL SCALE: 1' - 50' K TCAL SCALE: rs P1-OTtB- - �Df _ I z \ 1 \ \ I i8 Z o Q 6 FLARED END C ON \ [n w< \ R Mm b 1 1 Z Z W NQ z �o L f Mrenn I - 1+00 24 3+00 4+00 5+00 6+00 7+00 8+00 9+00 10+00 11+00 12+00 co Pli i�NOegg� NAe�gg z�wmagil coins T b N a dm eo&m a m`o�L�g o OII a%0 iawS M+� SHEET 21 OF 22 JOB NO REV d082.00 0 No Text