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HomeMy WebLinkAboutPARAGON POINT PHASE FIVE FINAL - 48 91L - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE REPORT FOR THE PARAGON POINT P.U.D. PHASE 5 Water Resources and Environmental Consultants 11. HISTORICAL DRAINAGE CONDITIONS 2.1 Overall Development Site Historical drainage conditions associated with the development were documented in the preliminary drainage report for the overall development plan. To facilitate the review of this report, pertinent information related to the historical drainage conditions is provided. The limits of the historical drainage area associated with the proposed development (overall development plan) are illustrated on Sheet 1. Also shown is the boundary of the proposed development. The overall development will encompass approximately 148.4 acres with approximately 35 acres along Fossil Creek remaining in its natural state. The existing drainage area consists of 167.1 acres and is characterized by relatively rugged terrain fringing the historical Fossil Creek floodplain. According to a geotechnical investigation completed by Empire Laboratories, Inc. in October 1991, the entire site has a six-inch layer of silty, organic topsoil and a sandy, silty clay subsoil. The ground cover consists predominantly of native dryland grasses which encompass approximately 50 percent of the site. To the west of Fossil Creek, the native ground is relatively steep (slopes up to 10 percent); the eastern area consists of steep bluffs (slopes of about 25 percent). Fossil Creek in the vicinity of the Paragon Point P.U.D. is a meandering, alluvial stream with numerous oxbows and zones of significant bank erosion. However, since the Phase 5 development is set back a minimum of 1,300 feet from Fossil Creek, stability of the creek is not an issue for Phase 5. Reference is made to the report "Fossil Creek Stability Study, Trilby Road to Lemay Avenue" [LA, 19921 for a detailed discussion of channel stability conditions in the vicinity of Phase 5. The proposed development is located within the Fossil Creek Drainage Basin. The Master Drainageway Planning Study documents historical conditions in the Fossil Creek basin. -- That study indicates that the existing condition 100-year return period discharge -near the upstream development boundary is 2,520 cfs. The Master Drainageway Planning Study also cites the 100-year existing condition discharge near the downstream boundary (Trilby Road) as 2,720 cfs. Stone Creek has an existing 100-year upstream inflow of 509 cfs (as computed by Lidstone & Anderson, Inc.), and a 100-year discharge at the Fossil Creek confluence of 522 cfs (from the Master Drainageway Planning Study). These flow values are indicated on Sheet 1. With overall existing hydrologic conditions well-defined in the Master Drainageway Planning Study, the historical condition hydrologic analysis for the proposed development was limited to the local runoff from the development site. The 100-year peak runoff from each subbasin is indicated on Sheet 1. These discharges correspond to unit runoff values of about 1.1 cfs/ac for the flatter subbasins (/i101 and #103), and approximately 2.3 to 3.0 cfs/ac for the E other four, steeper subbasins. The preliminary drainage report for the Paragon Point P.U.D. provides documentation of the hydrologic analysis of historical conditions. 2.2 Local Existing Drainage Conditions ' Local drainage conditions within Phase 5 of the Paragon'Point P.U.D. are affected by the drainage facilities and flow patterns developed in conjunction with Phase 4. Phase 5 is located directly south of Phase 4 and, as such, shares a common drainage basin divide at the Inorth end of Phase 5. Specifically, the frontage along Lemay Avenue from Trilby Road to Hawkeye Drive as well as the first 100 feet of Finch Court south of Hawkeye Drive within Phase 5 are tributary to the drainage facilities designed and/or constructed in conjunction with the Phase 4 development. The following paragraphs provide a brief summary of the existing I drainage facilities adjacent to the Phase 5 development. For reference, the existing topography and drainage facilities associated with Phase 4 are included as part of the grading and drainage plan given on Sheet 2. Flow collected along the eastern half of Lemay Avenue, adjacent to Phase 5, is conveyed as gutter flow to the north. As documented in the report "Final Drainage and Erosion Control Report, Paragon Point P.U.D., Phase 4 Development" [LA, 1993], upon widening of Lemay Avenue to a 70-foot flowline to flowline width, an 8-foot on -grade inlet is proposed to collect a portion of the flow at the intersection with Canvasback Drive. The remainder of the flow will be conveyed to a proposed curb inlet at the low point coincident with the crossing of Stone Creek north of Phase 4. IRunoff collected along Hawkeye Drive within Phase 4 is collected by a combination of curb inlets and a sidewalk culvert at the low point between Finch Court and Canvasback Drive. I —A-portion of the -flow -is -collected by an 18-inch ADS pipe and conveyed to the lower -of -two -- irrigation ponds on Stone Creek. The remainder of the flow is conveyed to the pond by a swale around the southern and eastern perimeter of Phase 4. It is proposed that the drainage area tributary to Lemay Avenue and also to the low point on Hawkeye Drive would be increased in conjunction with Phase 5. The drainage area to the Phase 4 perimeter swale would be decreased in the proposed condition. The hydrologic and hydraulic calculations performed as part of the Phase 4 analysis were revised to reflect the proposed site changes due to the Phase 5 development. The calculations, included in Appendix A, indicate a slight increase in discharge on Lemay Avenue and at the lowpoint on Hawkeye Drive. It is noted that despite the increased discharge, all drainage criteria is satisfied at both locations. Justification for the Phase 4 system meeting drainage criteria is also included in Appendix A. N III. DRAINAGE PLAN FOR THE PHASE 5 DEVELOPMENT 3.1 General The drainage system presented in this report has been developed in accordance with the guidelines established by the City of Fort Collins SDDC Manual dated May 1984 and revised in January 1991. Where applicable, design guidelines and information were also obtained from the Denver Regional Council of Governments Urban Storm Drainage Criteria Manual (USDCM). As indicated in the preliminary drainage report, no detention storage is planned for the development. This is commensurate with the Master Drainageway Planning Study which identifies no on -site detention for the Fossil Creek Drainage Basin. The drainage facilities within Phase 5 have incorporated provisions to convey both the initial and major storms. Based on a residential land use, the design storm frequencies were identified as the 2- and 100-year events for the initial and major storms, respectively. Preparation of the drainage plan required the delineation of subbasins within the Phase 5 Development. Design points were identified at all locations where design flow information was required or storm sewer inlets were necessary. Drainage basin boundaries and locations of the four design points are presented on Sheet 2. The City of Fort Collins will be responsible for maintenance of all storm sewers located in City rights -of -way and easements. The Paragon Point Homeowners Association will be responsible for all other on -site drainage facilities. 3.2 Proposed Drainage Plan A qualitative summary of the flow conditions within each basin and at each design point is provided in the following paragraphs. Discussion of the detailed design of drainage facilities, which are introduced in this section, is included in Section 3.4. Runoff from Subbasin A would be collected along the east side of future Lemay Avenue and conveyed to the north as gutter flow. As described in Section 2.2, runoff would be eventually conveyed to Stone Creek by two curb inlets located r near the intersection with Canvasback Drive and at Stone Creek. Runoff from Subbasin B would be collected in a perimeter swale along the west and south sides of the Phase 5 development. All flow in the swale would be 7 conveyed to the southeastern corner of the development. At this location, the flow in the swale would be released to an existing wetland area in the Fossil Creek floodplain. Runoff from Subbasin C would be collected along both sides of Finch Court and conveyed to a 10-foot curb inlet located in a sump on the eastern side of the cul- de-sac. The 100-year flow would be collected by the inlet and conveyed to the eastern boundary of Phase 5 in an 18-inch ADS pipe. The pipe flow would also be released to the existing wetland area. Runoff from Subbasin D would be generated along the eastern slope of the development and would be conveyed to the wetland as overland flow. 3.3 Hydrologic Analysis Due to the limited size of the subbasins within Phase 5, the Rational Method was selected as the method for estimating the runoff from the site. The Rational Method utilizes the SDDC Manual equation: Q = CfCIA (1) where Q is the flow in cfs, A is the total area of the basin in acres, Cf is the storm frequency adjustment factor, C is the runoff coefficient, and I is the rainfall intensity in inches per hour. In order to obtain a runoff coefficient for each subbasin, the percentage of impervious area was calculated.from the site -plan. The runoff coefficient was then calculated using the following - values: (a) 0.95 for all streets and impervious areas; (b) 0.20 for all open spaces and impervious areas; and (c) 0.60 for the small portion of multi -family lots within Phase 4 which are tributary to Phase 5. The frequency adjustment factor, Cf, 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 the rainfall intensity duration curves in the SDDC Manual (SDDC Figure 3-1). To obtain the rainfall intensity, the time of concentration must be determined. The following equation was utilized to determine the time of concentration: tC = tOf + tt (2) N i i where t is the time of concentration in minutes, t d is the initial or overland flow time in minutes, and t t is the travel time in the ditch, channel, or gutter in minutes. The initial, or overland, flow time was calculated with the SDDC Manual equation: tof = [1.87(l.1 - CCOL0.5]/(S)0.33 (3) where L is the length of overland flow in feet (limited to a maximum of 500 feet), S is the average basin slope in percent, and C and Cf are as previously defined. This procedure for computing time of concentration allows for overland flow as well as travel time for runoff collected in streets, gutters, channels, pipes, or ditches. The results of the hydrologic analysis are provided in Table 3.1; this table is also included on Sheet 2. All hydrologic calculations and associated information are contained in Appendix B. Table 3.1. Summary of Hydrologic Calulations. 1 A 0.75 0.69 2.6 7.0 1.3 4.5 2 B 0.91 0.41 2.1 6.0 0.8 2.8 3 C1 1.01 0.80 2.9 7. 22.3 7.1 3 - C2 0.33 0.77 3.2 7.0 0.8 2.2 3 C1, C2 1.34 0.79 2.9 7.0 3.1 9.3 4 D 0.76 0.46 3.2 7.0 1.1 3.1 4 B,C1, C2,D 3.01 0.59 2.1 6.0 3.7 13.3 0 3.4 Design of Drainage Improvements Finch Court is a local street which incorporates a roadway width (flowline to flowline) of 36 feet and is characterized by a 2 percent cross slope and a Fort Collins standard 4.75-inch rollover curb. Allowable gutter flows and maximum street encroachments for both the initial and major storms were estimated and evaluated based on the specifications set forth in the SDDC Manual. During the initial storm, runoff is not allowed to overtop the curb or the street crown. The maximum street runoff criteria during the major storm event limits the depth of water over the crown to less than or equal to 6 inches. The street carrying capacity was determined from a nomograph which was prepared to relate street slope to the allowable street flow (both with and without reduction factors). The calculations associated with the street capacity analysis are included in Appendix C. The street capacity calculations for Finch Court indicated that criteria is met for both the initial and major storm events. A single sump inlet is proposed at the southern end of Finch Court to collect the 100-year flow. The inlet was sized to collect runoff without violating the street encroachment criteria for the initial and major storms. In addition, the inlet sizing was performed to ensure that the inundation level remains within easements and rights -of -way for the major storm. Per SDDC p Manual guidelines, the theoretical capacity of the curb inlets was reduced by 15 percent. The inlet sizing calculations indicate that a 10-foot curb inlet would be required. It is noted that the D inlet, as sized, has the capacity to convey 1.8 times the 100-year flow prior to violating street inundation criteria. The calculations associated with the curb inlet design are also provided in Appendix C. Since the curb inlet operates in a sump condition, the storm sewer pipe at this location was sized based on the total 100-year discharge. An initial sizing calculation for the storm -J —sewer was accomplished-using-Manning's equation and assuming full pipe flow conditions. A detailed hydraulic analysis and hydraulic grade line determination of the final pipe design was performed using the UDSewer pipe hydraulic analysis model, developed by the Urban Drainage and Flood Control District. The calculations indicate that the pipe is capable of conveying the 100-year flow while keeping the hydraulic gradeline below the flowline elevation of the proposed inlet. Because the inlet is located in a sump condition, an additional calculation was performed which shows that the pipe is capable of conveying a flow twice the magnitude of the 100-year event with the hydraulic gradeline below the inlet flowline elevation. The hydraulic grade line computed by this analysis is shown on the Utility Plans. All storm sewer design calculations are provided in Appendix C. At the storm sewer outlet, riprap protection would be provided to reduce the potential for erosion. The riprap was sized based on procedures given in the USDCM: The outlet 10 protection is designed as a buried riprap installation using Class 6 riprap (City of Fort Collins SDDC Manual gradation). Details and specifications for all storm sewer outlet protection installations are given on Sheet 2. All riprap design calculations are given in Appendix C. In addition to riprap protection at the pipe outlet, a 20-foot by 20-foot erosion control mat would be installed directly downstream of the riprap area. The perimeter swale was designed to convey the 100-year flow around the site with a minimum of 1-foot of freeboard. A normal depth analysis was performed using slope -area methodology within the HEC-2 Water Surface Profiles computer model. The hydraulic analysis indicated that the 100-year flow velocities in the swale would be relatively small, ranging from 1.3 to 3.4 fps. As a result, a 2-foot wide concrete trickle channel would be placed in the bottom of the swale. A typical cross section for the swale is given on Sheet 2. It is noted that due to space restrictions, the grass -lined swale is designed with side slopes of 3H:1V. A variance is requested to allow side slopes steeper than the prescribed 4H:1 V. Results of the normal depth analysis for the swales may be found in Appendix C. Class 6 riprap (buried) would also be placed downstream of the concrete trickle channel. Similar to the pipe outlet, an erosion control mat would be installed downstream of the swale's riprap pad. 3.5 Fossil Creek Floodplain Considerations The limits of both the existing and developed condition 100-year floodplains were delineated and documented in the preliminary drainage report. Further discussion was presented in the Final Drainage Report for Phase 1 [LA Inc., 1992]; both the existing and future condition floodplains throughout the entire Paragon Point development were delineated and presented in that report. The portions of the developed condition floodplain in the vicinity of Phase 5 are - — —delineated on Sheet 2.-- It -is noted that the floodplain encroaches on a small portion of -the -eastern fringe of the Phase 5 development site; however, this parcel is platted as an open space. Due to the ponded condition of Fossil Creek upstream of Trilby Road, the loss of storage volume within the floodplain associated with the fill along the eastern portion of the Phase 5 site can be compensated by removing material from elsewhere within the floodplain equal to the volume of fill. Therefore, it is required that the portion of fill for Phase 5 which encroaches the floodplain be removed from a nearby area within the floodplain. 11 I IV. EROSION CONTROL PLAN The Erosion Control Plan for this site was designed in accordance with the criteria set forth in the SDDC manual. Specific erosion control measures implemented as part of this plan include the use of a gravel inlet filter, straw bale barriers, silt fence, reseeding and mulching and the implementation of an erosion control blanket. An inlet filter would be installed shortly after construction of the, proposed inlet to trap any sediment which may be transported prior to seeding. Straw bale barriers would be placed at three locations within the swale. A silt fence would be placed at the eastern limit of disturbance to further inhibit the movement of sediment to the existing wetland. The hillslope on the eastern end of the site will be treated with either an erosion control blanket or hydraulic mulch to inhibit the initial transport of sediment. It is also noted that the site would be reseeded and mulched immediately following final grading. Erosion control effectiveness calculations were performed for each of the subbasins within the Phase 5 development based on the methodologies given in the SDDC Manual. An overall basin effectiveness was then calculated based on a weighted average of the each of the subbasins. It is noted that the erosion control effectiveness calculations are greater than the performance standard for the overall development. r Calculations for the performance standard and the erosion control effectiveness are given in Appendix D. Table 4.1 outlines the construction sequence for the Erosion Control Plan; this table is also included on Sheet 2. The erosion control cost estimate for the single-family development is provided in Table 4.2. The cost estimate results indicate that a total security of $ 2,250 would be required for Phase 5. 12 Table 4.1. Construction Sequence. Project: Paragon Point Phase 5 Standard Form C Sequence for 1925 Only Completed By: CLD Date: 5/22/95 Indicate by use of a bar line or symbols when erosion control measures will be installed. Major modifications to an annrnued schedule may reouire submitting a new schedule for approval by the City Engineer. Year 95 96 Month Aug Sep Oct Nov Dec Jan Feb Mar Apr Demolition Overlot Grading Wind Erosion Control: Soil Roughing Perimeter Barrier Additional Barriers Vegetative Methods Soil Sealant Other Rainfall Erosion Control Structural: J Sediment TrapBasin Inlet Filters Straw Barriers Silt Fence Barriers Sand Bags Bare Soil Preparation Contour Furrows Terracing Asphalt/Concrete Paving . Other -- Vegetative: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting Sod Installation Nettings/Mats/Blankets Other Structures: Installed by CONTRACTOR Maintained by OWNER Vegetation/Mulching Contractor To Be Decided by Bid Date Submitted: 5/3/95 Approved by City of Fort Collins on 13 Table 4.2. Erosion Control Cost Estimate. EROSION CONTROL 1 Reseed/Mulch 3 AC. $ 500.00 $ 1500.00 2 Silt Fence 300 L.F. $ 3.00 $ 900.00 3 Gravel Inlet Filter 1 EA. $ 300.00 $ 300.00 4 Straw Bale Barrier 3 EA. $ 50.00 $ 150.00 CONSTRUCTION COST $ 2,850.00 1.5 X (CONST. COST) $ 4,275.00 TOTAL SECURITY $ 4,275.00 CITY RESEEDING COST 1 Reseed/Mulch 3 AC. $ 500.00 $ 1,500.00 CONSTRUCTION COST $ 1,500.00 1.5 X (CONST. COST) $ 2,250.00 TOTAL SECURITY $ 2,250.00 14 FINAL DRAINAGE REPORT FOR THE PARAGON POINT P.U.D. PHASE 5 PREPARED FOR: City of Fort Collins Stormwater Utility 235 Mathews Fort Collins, CO 80524 - — --- PREPARED BY: Lidstone & Anderson, Inc. 736 Whalers Way, F-200 Fort Collins, CO 80525 (LA Project No. COTST09.8) May 22, 1995 V. REFERENCES 1. Lidstone & Anderson, Inc., November, 1991. "Preliminary Drainage Plan for Overall Development Plan for Paragon Point P.U.D." Prepared for TST, Inc., Fort Collins, Colorado. 2. Lidstone & Anderson, Inc., April, 1992. "Final Drainage and Erosion Control Report, Paragon P.U.D., Phase 1 Development." Prepared for City of Fort Collins, Stormwater Utility, Fort Collins, Colorado. 3. Lidstone & Anderson, Inc., October, 1992. "Fossil Creek Stability Study, Trilby Road to Lemay Avenue." Prepared for City of Fort Collins, Stormwater Utility, Fort Collins, Colorado. 4. Lidstone & Anderson, Inc., August, 1993. "Final Drainage and Erosion Control Report, Paragon Point P.U.D., Phase 4." Prepared for City of Fort Collins, Stormwater Utility, Fort Collins, Colorado. 5. Lidstone & Anderson, Inc., May, 1994. "Drainage Report Amendment for Paragon Point P.U.D., Phase 4 Development." Prepared for City of Fort Collins, 6. Simons, Li & Associates, Inc., August 1982. "Fossil Creek Drainage Basin, Master Drainageway Planning Study". Prepared for the City of Fort Collins, Larimer County, and the Colorado Water Conservation Board. 15 LIDSTONE & ANDERSON, INC. Water Resources and Environmental Consultants 736 Whalers Way, Suite F7200 Fort Collins, Colorado 80525 (970) 226-0120 May 22, 1995 Mr. Basil Hamdan City of Fort Collins Stormwater Utility 235 Mathews Street Fort Collins, CO 80524 Re: Final Drainage Report for the Paragon Point P.U.D., Phase 5 (LA Project No. COTST09.8) Dear Basil, Lidstone & Anderson, Inc. (LA) is pleased to submit the Final Drainage Report for the Fifth Phase of the Paragon Point P.U.D. The design of the drainage facilities conforms to the Preliminary Drainage Report for the Paragon Point P.U.D. [LA, 19911 which serves as an overall drainage plan for the development. The hydraulic and hydrologic evaluation of the site, documented herein, was performed in accordance with the specifications set forth in the City of Fort Collins SDDC Manual. If you have any questions regarding the procedures and results given in this report, please feel free to call us. Sincerely, LIDSTONE & ANDERSON, INC. Christ her L. Doherty, E.I.T. Project En ' r GreVrJ:/Koch, P.E. Senior Engineer CLD/GJK/tlt Attachment Branch Office: Box 27, Savery, Wyoming 82332 TABLE OF CONTENTS I. INTRODUCTION ....................................... 1 1.1 Scope and Purpose of the Study ........................... 1 1.2 Location and Description of the Site ........................ 1 1.1 Previous Studies .................................... 1 II. HISTORICAL DRAINAGE CONDITIONS ........................ 5 2.1 Overall Development Site ............................... 5 2.2 Local Existing Drainage Conditions ......................... 6 III. DRAINAGE PLAN FOR THE PHASE 5 DEVELOPMENT .............. 7 3.1 General .......................................... 7 3.2 Proposed Drainage Plan ................................. 7 3.3 Hydrologic Analysis .................................. 8 3.4 Design of Drainage Improvements ......................... 10 3.5 Fossil Creek Floodplain Considerations ..................... 11. IV. EROSION CONTROL PLAN ............................... 12 V. REFERENCES ........................................ 15 FIGURES Figure 1.1. Vicinity Map of the Paragon Point P.U.D. .................... 2 Figure 1.2. Location Map of -the Phase 5 Development ...............: - : 3— TABLES Table 3.1. Summary of Hydrologic Calculations . ...................... 9 Table 4.1. Construction Sequence ................................ 13 Table 4.2. Erosion Control Cost Estimate . .......................... 14 i TABLE OF CONTENTS (CONTINUED) APPENDICES Appendix A: Reanalysis of Drainage Facilities for Phase 4 Appendix B: Hydrologic Analysis Appendix C: Design of Drainage Facilities Appendix D: Erosion Control Calculations SHEETS Sheet 1: Summary of Existing Condition Hydrology Sheet 2: Final Grading, Drainage and Erosion Control Plan ii I. INTRODUCTION 1.1 Scope and Purpose of the Study This report presents the results of the drainage evaluation for the Paragon Point P.U.D., Phase 5 Development. A hydrologic analysis of the proposed development plan was completed to determine the location and magnitude of storm runoff. Drainage facilities were designed and evaluated to ensure that the structures could safely convey runoff from the site in accordance with the City of Fort Collins Storm Drainage Design Criteria (SDDC) Manual. The purpose of this report is to evaluate the Phase 5 development and prepare a stormwater management plan that addresses the overall storm drainage planning issues, and the requirements for engineering design of specific storm drainage facilities. 1.2 Location and Description of the Site The Paragon Point P.U.D. is a proposed residential subdivision encompassing the majority of the SW 1/4 of Section 7, Township 6 North, Range 68 West, in Fort Collins, Colorado. This development is bounded on the east by the Union Pacific Railroad (UPRR), on the south by Trilby Road, on the west by Lemay Avenue, and on the north by the city -owned SouthRidge Golf Course. A vicinity map illustrating the project location is provided in Figure 1.1. The proposed development is situated within the Fossil Creek drainage basin with both Fossil Creek and Stone Creek conveying storm runoff through the site. Phase 5 represents the final development phase of the Paragon Point P.U.D. The`entire development consists of 148.4 acres and is primarily zoned low density planned residential (RLP)--Phase 5-consists-of-a three -acre multi -family (townhouse) site at the northeast -corner of Lemay Avenue and Trilby Road. The limits of the Phase 5 development are presented on Figure 1.2. 1 ' 1.3 Previous Studies The Preliminary Drainage Plan for the Overall Development, Paragon Point P.U.D. [Lidstone & Anderson, Inc., 1991] was submitted on November 27, 1991 and approved by the Fort Collins Stormwater Utility in December 1991. The preliminary drainage report documents 1 e nR� y 0r Q3 n d' Rm. HA NY BOA E.0 2 d P RN °ar G¢ i g CL a�.\J s� v T J z °yam at _. Cratr' /. wRr s i t' SN" fx EORTNER J 3 II PARAGON POINT I � < E T,,Ibv Rd 34 "" •� — a 1 TRILBY ROAD'; 1 m pr iota R0. u \A 4 , ROBERT BENSON LAKE m SCALE: 1 " = 2000' u° Figure 1.1. Vicinity Map for the Paragon Point P.U.D. 2 G I / ♦ ____ _____ __ 1 I __ ___ ____ __ __ - - 1 f/ 1it� —i i'-- I ♦ ��� I II i 1 \ iL-- --1\ r-- T I L -- I f ;I M = i O\ UPPER \ \ 1 I POND - LONER �� 1 POND q.�r0' ""'acre �__-- \ UMIT OFPHASE 5 1 `\ 1 DEVELOPMENT NOT TO SCALE — I TRILBY ROAD Figure 1.2. Location Map of Phase 5 Development. 3 historical drainage conditions for the development, as well as a proposed drainage plan associated with the overall development of Paragon Point. Due to the location of the proposed development within the Fossil Creek Drainage Basin, a report prepared by Simons, Li & Associates, Inc. in 1982 entitled "Fossil Creek Drainage Basin Master Drainageway Planning Study" was also utilized to document historical drainage conditions. The Master Drainageway Planning Study was used extensively in preparing the preliminary drainage report for the overall development plan. 4