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HomeMy WebLinkAbout10.24.2003 Preliminary Engineering Report Woodlawn Storm Sewer and W Shadowbend Paving and Drainage City of Friendswood Preliminary Engineering Report Woodlawn Storm Sewer Problem Area No. 1 and West Shadowbend Ave. Paving and Drainage Improvements October, 2003 Prepared for City of Friendswood, ®®®®®�°°,o7. Texas F,.RRY D. SCHUELEl9® ziaGooGeoeGoeoGeoeG000socgi o � °�©o© 42247 ®l ® ��� ° .` ®® ®°®®�®® Freese and Nichols, Inc. � ' 4le ' %WWI 2010 E. Broadway Pearland, Texas 77581 (281) 485-2404 Freese and Ni' C h �s, Inc. Engineers Environmental Scientists Architects 2010 East Broadway Pearland, TX 77581-5502 281/485-2404 281/485-4322 fax www.freese.com October 24, 2003 • Mr. Skipper Jones Capital Improvements Project Coordinator City of Friendswood 910 South Friendswood Drive Friendswood, Texas 77546-4856 Re: Preliminary Engineering Report for Woodlawn Drive Storm Sewer Problem Area No. 1 West Shadowbend Avenue Paving and Drainage Improvements Dear Mr. Jones: Freese and Nichols, Inc. appreciates the opportunity to submit five (5) copies of the Preliminary Engineering Report to the City of Friendswood, for the Woodlawn Drive Storm Sewer Problem Area No. 1 and the West Shadowbend Avenue Paving and Drainage Improvements projects. If you have any questions or need further clarifications, please do not hesitate to call. We look forward to working with you during the design of the above referenced projects. Yours truly, FREESE AND NICHOLS, INC. bSeiaLe,L_ pE . Larry D. chuelein, P.E. Principal and Sr. Project Manager Preliminary Engineering Report for Woodlawn Drive Storm Sewer Problem Area No. 1 and West Shadowbend Avenue Paving and Drainage Improvements for City of Friendswood TABLE OF CONTENTS Page No. Executive Summary ES— 1 thru ES—5 General Description of Project Page 1 II. Project Scope of Services Page 1 A. Woodlawn Dr. Storm Sewer Problem Area No. 1 Page 1 B. West Shadowbend Ave. Paving and Drainage Improvements Page 1 C. Woodlawn Dr. Drainage Problem Page 2 III. Review of Master Drainage Plan(MDP)Options Page 4 A. Woodlawn Area Storm Sewer Improvements Page 4 1. Solution Option No. 1 —Detention Basin Page 4 2. Solution Option No. 2—New Storm Sewer Pipes Page 5 3. Solution Option No. 3 —Combination New Pipes and Ditch Page 6 4. Alternative Solution No. 4—Sheet Flow And R. C. Boxes Page 7 B. Addressing the Woodlawn Dr. and West Shadowbend Ave. Flooding Problems Page 8 C. Areas Along West Spreading Oaks Dr. from Laurel to Woodlawn Drive Page 11 D. Areas Along West Shadowbend Ave. East of The Intersection of Woodlawn Drive Page 12 E. Analysis of the Existing Tributary of Coward's Creek Drainage Channel Page 12 IV. West Shadowbend Ave. Reconstruction Page 17 A. Existing Roadway Page 17 B. Right-of-Way Page 17 C. Land Use Page 17 D. Drainage Page 18 E. Proposed Roadway Profile of West Shadowbend Ave. Page 18 F. Opinion of Probable Cost of Construction Page 20 FSW 03197 - 1 TOC Page No. V. Recommendations A. Woodlawn Drive Storm Sewer Problem No. 1 Page 20 B. West Shadowbend Ave. Paving and Drainage Improvements Page 21 APPENDIX: Preliminary Opinion of Probable Cost of Construction Estimates: Exhibit 1. West Spreading Oaks-Outfall to Woodlawn Appendix Exhibit 2. Woodlawn Drive—Each side of Shadowbend Follows Exhibit 1 Exhibit 3. West Spreading Oaks—Laurel to Woodlawn—Additive Alternate No. 1 Follows Exhibit 2 Exhibit 4. West Shadowbend Drive—Laurel to Woodlawn Drive Additive Alternative No. 2 Follows Exhibit 3 Exhibit 5 West Shadowbend Ave. to Woodlawn Drive Follows Exhibit 4 Table DA Summary(Rational method calculations for 5-year 100 Year Follows Exhibit 5 Table LU-1 Summary of Existing Developed Area Conditions Follows DA-1 Table LU-2 Summary of Existing Developed Area Conditions Follows LU-1 Table 1 Determination of Design Discharge(Existing 5-year) Follows LU-2 Table 1-A Determination of Design Discharge(Existing 100-year) Follows Table 1 Table 2 Determination of Design Discharge(Developed 5-year) Follows Table 1-A Table 2-A Determination of Design Discharge(Developed 100-year) Follows Table 2 Table 3 Determination of Design Discharge Detention Area North(Developed 5-year) Follows Table 2-A Table 3-A Determination of Design Discharge Detention Area North(Developed 100-year) Follows Table 3 Table 4 Determination of Design Discharge,Brook Meadows To Coward's Creek(Developed 5-year) Follows Table 3-A Table 4-A Determination of Design Discharge,Brook Meadows To Coward's Creek(Developed 100-year) Follows Table 4 Table 5 Woodlawn Drainage Area to Coward's Creek (Developed 5-year) Follows Table 4-A Table 5-A Woodlawn Drainage Area to Coward's Creek (Developed 10-year) Follows Table 5 Table 6 Laurel and Spreading Oaks Existing 5-year Follows Table 5-A Table 6-A Laurel and Spreading Oaks Existing 100-year Follows Table 6 Table 7 Laurel and Spreading Oaks,Reach 2, Existing 5-year Follows Table 6-A Table 7-A Laurel and Spreading Oaks,Reach 2,Existing 100-year Follows Table 7 Table 8 Laurel to Woodlawn(Developed 5-year) Follows Table 7-A Table 8-A Laurel to Woodlawn(Developed 100-year) Follows Table 8 FSW 03197 - 2 TOC Page No. Cross-Sections: Woodlawn at 192' S. of Shadowbend at W.S. elevation 28.32 ft. Follows Table 8-A Woodlawn at 192' S. of Shadowbend at W.S. elevation 28.50 ft. Follows one above Shadowbend Street surface flow at W.S. elevation 28.32 ft. Follows Woodlawn Cross-Section Shadowbend Street surface flow at W.S. elevation 28.50 ft. Follows one above. Woodlawn cross-section near Junior High School W. S. elevation 28.90 Follows Shadowbend Cross-Section Coward's Creek Hydraulic Calculation at Sta. 0+54 Follows one above Coward's Creek Hydraulic Calculation at Sta. 1+50 Follows Sta. 0+54 Coward's Creek Hydraulic Calculation at Sta. 4+75 Follows Sta. 1+50 Coward's Creek Hydraulic Calculation at Sta. 7+12 Follows Sta.4+75 48" Culvert Calculations Follows Sta. 7+12 Shadowbend 30" Storm Sewer Pressure Flow Capacity Follows 48' Culvert Calculations Woodlawn 42" Storm Sewer Pressure Flow Capacity Follows Shadowbend 30" Shadowbend Storm Drain Pipe Capacity Calculations Follows Woodlawn 42" Figures: Figure 1 Rainfall Intensity Duration Curves Follows Shadowbend Storm Drain Pipe Cap. Cal. In Appendix Figure 2 Woodlawn Drive Sag Inlet Storm Drain& Sheet Flow Diagram Page 9 Figure 3 Tributary of Coward's Creek Station 0+34 Page 13 Figure 4 Tributary of Coward's Creek Station 0+54 Page 14 Figure 5 Tributary of Coward's Creek Station 1+50 Page 14 Figure 6 Tributary of Coward's Creek Station 4+75 Page 14 Figure 7 Tributary of Coward's Creek Station 6+60 Page 15 Figure 8 Concrete Driveway over Dual 48-Inch R.C.P.'s At Station 6+60 Page 15 Figure 9 Tributary of Coward's Creek Station 7+12 Page 16 Chart A Coward's Creek Tributary capacity and W.S. elevation Follows Woodlawn Cross-section in Appendix TABLE: Table A Tributary of Coward's Creek, Calculated Water Surface Elevation at Various Cross-Sections Page 16 FSW 03197 - 3 TOC Page No. DRAWINGS: Exhibit Option No. 1 Woodlawn Drive Drainage Area Problem(1) First Drawing Exhibit Option No. 2 Woodlawn Drive Drainage Area Problem(2) Follows Exhibit Option No. 1 Exhibit Option No. 3 Woodlawn Drive Drainage Area Problem(3) Follows Exhibit Option No. 2 Exhibit Option No. 4 Woodlawn Drive Drainage Area Problem(4) Follows Exhibit Option No. 3 Exhibit Option No. 4-A Woodlawn Drive Drainage Area Problem(4-A) Follows Exhibit Option No. 4 Exhibit WSB DA-1 Drainage Area Map for West Shadowbend Avenue Follows Exhibit Option 4-A Exhibit WSB-1 Prop.Roadway and Drainage Improvements Follows Exhibit WSB DA-1 Exhibit WSB-2 Prop.Roadway and Drainage Improvements Follows Exhibit WSB-1 FSW 03197 - 4 TOC EXECUTIVE SUMMARY INTRODUCTION This preliminary design report addresses two projects. The first project has been identified in the City of Friendswood's Master Drainage Plan(MDP) as the Woodlawn Drive Storm Sewer Problem Area No. 1. The second project is the paving and drainage improvements to West Shadowbend Avenue from Sunset Drive to Woodlawn Drive. II. Woodlawn Drive Storm Sewer Problem Area No. 1 The problem is that Woodlawn Drive frequently floods between West Shadowbend Avenue and Dawn and Heritage. This flooding is a result of an approximate 2.5-foot rise in the elevation of Woodlawn Drive near its intersection with West Shadowbend Avenue. The elevated intersection produces a damming effect and ponds storm water back to Heritage and Dawn. The higher street elevation is apparently the result of changing Woodlawn Drive from a roadside ditch street to a curb and gutter section. The Master Drainage Plan identified three options to reduce the risk of flooding. They are as follows: A. Construction of a detention basin in the vicinity of Woodlawn Drive and West Shadowbend Avenue. B. Installation of new storm sewer pipes and inlets and clearing of Coward's Creek tributary. C. Installation of a combination of new storm drain pipes,inlets and a new drainage ditch. After an evaluation of the above options,Freese and Nichols, Inc. does not believe they are acceptable solutions to reducing the risk of flooding along Woodlawn Drive. The evaluations of the options can be found in the report. Freese and Nichols, Inc. evaluated a fourth option described as follows: D. Develop options to sheet flow excess storm water runoff to reduce risk of flooding along Woodlawn Drive at West Shadowbend Avenue and develop options to lessen impacts on the tributary of Coward's Creek using pre-cast reinforced concrete box sections The fourth option evaluated surface sheet flow conditions along Woodlawn Drive at West Shadowbend Avenue and the use of pre-cast reinforced concrete box sections to reduce the depth of the storm sewer collection system along West Spreading Oaks Drive from Woodlawn Drive to the Coward's Creek tributary outfall. The analysis determined ES - 1 that the tributary of Coward's Creek water surface would not be significantly increased with the proposed drainage improvements. It is recommended that a third 48-inch culvert pipe be installed under the existing driveway at approximate Station 6+60 for and estimated construction cost of$13,000.00. This option eliminated channel cleaning/excavation along a tributary of Coward's Creek near West Spreading Oaks Drive. This will save the City time and money for acquiring drainage easements and permits for clearing the drainage channel. The evaluation can be seen in the report section. The required sheet flow to reduce the risk of flooding along Woodlawn Drive north of West Shadowbend Avenue can be achieved by lowering Woodlawn Drive. A distance of approximately 190 feet south of the West Shadowbend Avenue intersection will be needed to be reconstructed to a flatter slope. Additional curb inlets will be constructed at the intersection. Several sections of existing storm sewer will need to be replaced with negative slopes. The 30-inch storm sewer pipe on the east side of Woodlawn Drive will need to be replaced with a 36-inch pipe. The cost of construction for the reconstruction of Woodlawn Drive around the West Shadowbend intersection is estimated to be approximately$171,000.00. The detailed breakdown of the estimate is shown on Exhibit-2 in the Appendix. The storm sewer system from the outfall of the tributary of Coward's Creek up to Woodlawn Drive will utilize the existing storm sewer pipes with the addition of 10' x 3', 6' x 3' and 7' x 4' reinforce concrete box pipes. To preserve the existing trees along West Spreading Oaks, the new storm sewer system will need to be constructed in the existing roadway. Hot mix asphaltic concrete overlay similar to what presently exists will be utilized to repair the roadway pavement. The estimated construction cost from the Coward's Creek outfall to Woodlawn Drive is approximately $289,300.00. The detailed estimate can be seen in Exhibit— 1 in the Appendix. The opinion of probable cost of construction for solving the Woodlawn Drive drainage problem is estimated to be $473,300.00. Additive alternatives to reduce the risk of flooding along West Spreading Oaks from Laurel to Woodlawn Drive and along West Shadowbend Avenue from Laurel to Woodlawn Drive were evaluated. Additive alternative No. 1 (along West Spreading Oaks) estimated construction cost is $233,300. Additive Alternative No.2 (along West Shadowbend Avenue) estimated construction cost is $147,800. A summary of the project costs are as follows: ES - 2 • SUMMARY OF RECOMMENDED WOODLAWN DRIVE STORM SEWER PROBLEM AREA NO. 1 PROJECT COSTS DESCRIPTION ESTIMATED COST Woodlawn Drive Paving &Drainage Improvements $171,000 West Spreading Oaks Storm Sewer Improvements $289,300 48-inch RC Culvert with Headwalls $ 13,000 Sub-Total $473,300 Additive Alternative No. 1 (Laurel -W. Spreading Oaks) $233,300 Additive Alternative No. 2 (Laurel -W. Shadowbend) $147,800 Total Opinion of Probable Cost of Construction $854,400 Estimated Engineering Fees $ 70,000 Total Estimated Project Cost $911,400 Freese and Nichols, Inc. recommends that option four be designed and bid for construction. FNI also recommends that Additive Alternatives No. 1 and 2 be designed and bid. This will provide the City with an opportunity to match estimated construction cost to the available funds. III. WEST SHADOWBEND AVENUE PAVING AND DRAINAGE IMPROVEMENTS FROM SUNSET DRIVE TO WOODLAWN DRIVE This report also addresses the design of paving and drainage improvements for West Shadowbend Avenue from Sunset Drive to Woodlawn Drive. The typical roadway section proposed is a 28-foot back-of-curb to back-of-curb (BC-BC) concrete pavement section with associated drainage improvements. The drainage along West Shadowbend Avenue will be divided into the following sub-areas (westernmost to easternmost): • Outfall at Sunset Drive • Outfall at a tributary of Coward's Creek • Outfall at the existing 42-inch storm sewer along Sedora Drive, and • Outfall drainage channel along David Street The opinion of probable cost of construction for the paving and drainage improvements to West Shadowbend Avenue is $1,091,300.00. The ES - 3 estimated engineering fee is $86,400. The total estimated project is $1,177,700. IV. RECOMMENDATIONS 1. Woodlawn.Drive Storm Sewer Problem Area No. 1 a. Design and construct Woodlawn Drive paving and drainage improvements and West Spreading Oaks Drive storm sewer improvements. b. Design and Bid Additive Alternatives 1 and 2 with Option No. 4. If funds are available construct both alternatives. Additive Alternative No. 1 should have a higher priority that Additive Alternative No. 2. If funds are not available after the bids are received, Delay storm sewer improvements from Laurel to Woodlawn Drive along West Shadowbend Avenue and West Spreading Oaks Drive until funding for the roadway reconstruction is available. 2. West Shadowbend Avenue Paving and Drainage Improvements a. Design and construct in one construction project with Woodlawn Drive Storm Sewer Problem Area No. 1,project. 3. Schedule a. Freese and Nichols,recommends that a meeting with the junior high school administration staff be held to coordinate the available dates for construction of Woodlawn Drive in the vicinity of the bus barn. It's anticipated that the paving and drainage construction items along Woodlawn Drive would need to start as soon as school is out for the summer and be completed before school begins in August to avoid bus routing conflicts with the school. ES - 4 GENERAL DESCRIPTION OF PROJECT Based on our Engineering Service Contract with the City of Friendswood, dated April 7,2003,this preliminary engineering report will address two projects. The first project will evaluate three options identified as the Woodlawn Drive Storm Sewer Problem Area No. 1 in the City's Master Drainage Plan. The second project is the paving and drainage improvements for West Shadowbend Avenue from Sunset Drive to Woodlawn Drive.Design criteria from Section IV Street Paving Design Requirements and Section V Storm Drainage Design Requirements found in the City of Friendswood's Design Manual were used in the preparation of the following report. The scopes of services for the projects are as follows: II. PROJECT SCOPE OF SERVICES A. Woodlawn Drive Storm Sewer Problem Area No. 1 The City's Master Drainage Plan (MDP)identified three options to reduce flooding on Woodlawn between West Shadowbend Avenue and Dawn. The options to be evaluated are: 1. Detention Basin—In the vicinity of Woodlawn Drive and West Shadowbend Avenue 2. Installation of New Storm Sewer Pipes and Inlets and Clearing of Coward's Creek Tributary 3. Installation of a Combination of New Storm Drain Pipes, Inlets and a New Drainage Ditch 4. Develop Sheet Flow Options to Reduce Risk of Flooding Along Woodlawn Drive at West Shadowbend Avenue and Develop Options to Lessen Impacts on the Tributary of Coward's Creek Using Pre-Cast Reinforced Concrete Box Sections The fourth option will analyze the possibilities to surface sheet flow a sufficient amount of storm water down Woodlawn Drive and West Shadowbend Avenue that will reduce the risk of flooding. Also the use of pre-cast reinforced concrete box sections will be evaluated to determine if the depth of the storm sewer collection system can reduce the amount of channel cleaning/excavation along a tributary of Coward's Creek near West Spreading Oaks Drive. B. West Shadowbend Avenue Paving and Drainage Improvements This report also addresses the design of paving and drainage improvements for West Shadowbend Avenue from Sunset Drive to Woodlawn Drive. The typical roadway section proposed is a 28-foot back-of-curb to back-of-curb (BC-BC) concrete pavement section with associated drainage improvements. The preliminary drainage areas for West Shadowbend 1 Avenue will be defined along with the outfall points and major storm sewers. The preliminary engineering design will address existing City utilities and their effect on the proposed paving and storm sewer collection system improvements. A preliminary opinion of probable cost of construction has been prepared based on the proposed paving and drainage improvements. Field design surveying was performed for the limits of the proposed improvements. C. WOODLAWN DRIVE DRAINAGE PROBLEM Localized flooding occurs frequently at the intersections of Heritage, Dawn and West Shadowbend Avenue at Woodlawn Drive. This flooding is a result of an approximate 2.5-foot rise in the elevation of Woodlawn Drive near its intersection with West Shadowbend Avenue. The elevated intersection produces a damming effect at this intersection and ponds storm water back to Heritage and Dawn. The higher street elevation is apparently the result of changing Woodlawn Drive from a roadside ditch street to a curb and gutter section. Individual storm drain collection systems converge at the intersection of Woodlawn Drive and West Shadowbend Avenue. A parallel storm sewer system consists of 36-inch and 42-inch pipes on the west side and 30-inch and 36-inch on the east side of Woodlawn Drive. From this point the storm sewer collection system runs south along Woodlawn Drive toward its ultimate outfall in a tributary of Coward's Creek. The tributary is located south of the West Spreading Oaks Drive and Woodlawn Drive intersection. The drainage basins north of the West Shadowbend Avenue and Woodlawn Drive intersection converge at this point. Approximately 21.7 acres (detention area north) from areas north and 18.6 acres (Laurel to Woodlawn Dr) from areas east of this intersection enter the storm sewer collection system. The area is composed of vacant lots,residential and commercial areas (including the bus barn for Friendswood I.S.D.). The required capacity to convey the 5-year design storm from the intersection of Woodlawn Drive and West Shadowbend Avenue is approximately 89.98 cfs. Table DA-1 indicates the flow calculations. The existing gravity flow capacity of the parallel system is approximately 45 cfs. Further south along Woodlawn Drive the Junior High School property and residential areas drain into this storm sewer system, further impacting the capacity. Finally, there is localized flooding along areas of West Shadowbend Avenue east of its intersection with Woodlawn Drive. The existing storm sewer system along this route consists of 24-inch and 30-inch pipes. Near the intersection of Woodlawn Drive and West Shadowbend Avenue the required capacity to convey the City of Friendswood 5-year design storm is approximately 64 cfs. From the survey supplied by C.L. Davis &Co., the existing 30-inch storm sewer near this intersection has a positive slope(pipe slopes in wrong 2 direction). As a result the storm sewer collection system is under-capacity. The proposed collection system pipes will need to be replaced with larger pipes to convey the 5-year storm. The flooding being experienced at the Woodlawn Drive and West Shadowbend Avenue intersection can also be attributed to the existing storm sewer system along Woodlawn Drive. Two sections of 42-inch RCP between storm sewer manholes have positive slopes, +1.12% &+1.4% and one section has a slope of 0.07 %reducing the capacity to approximately 27 cfs. These storm sewer grades result in insufficient capacity to convey the City of Friendswood 5-year storm event of approximately 47.8 cfs at the sag inlet. The 42-inch storm sewer capacity is reduced to be only able to carry approximately the 2-year 1-hour return frequency design storm under gravity flow conditions. Figure 1 is a plot of the City's Rainfall, Intensity and Duration Curves. Backing into the rainfall intensity for a runoff of 27 cfs with a drainage area of 21.73 acres and a runoff coefficient of 0.59 the rainfall intensity of 2.1 inches per hour is derived. The National Weather Bureau Technical Paper No. 40 closely approximates the 2.1 inches with the 2-year 1 hour storm of 2.35 inches. Flooding has occurred along West Spreading Oaks Drive near the Junior High School. The existing storm sewer system along this route consists of 18-inch and 24-inch pipes. The required capacity to convey the City of Friendswood 5-year design storm is approximately 40 cfs near the intersection of Laurel and West Spreading Oaks Drive and approximately 50 cfs near the intersection of Woodlawn Drive and West Spreading Oaks Drive. The highest capacity in the existing storm sewer system is 9.35 cfs. The existing dual 30-inch storm sewer pipes which parallel West Spreading Oaks Drive from Woodlawn Drive to the tributary of Coward's Creek has a capacity of Approximately 70 cfs under pressure flow conditions. The drainage area from the Brooke Meadows development contributes approximately 38 cfs during the 5-year. An estimated existing flow in the tributary channel may range from 108 cfs to 200 cfs depending on the depth of water in the street providing head pressure to force the runoff flow through the storm sewer pipes. Layout of the existing storm sewer collection system along Woodlawn Drive can be seen on Exhibit EXIST-1. Tables LU-1 and LU-2 indicate the various land uses for the various drainage areas. Tables 1 thru 8A indicate the time of concentration, composite runoff coefficients and rational method calculations for the 5 and 100-year design storms. Table DA-1 is a summary of the runoff peak flows for the 5 and 100-year design storms for existing and future developed conditions. 3 Presently the outfall for the existing storm sewer system discharges into a tributary of Coward's Creek just south of the intersection of Woodlawn Drive and West Spreading Oaks Drive. This tributary is overgrown with trees and vegetation. See Figures 3 thru 9 for pictures of the drainage channels analyzed. Presently,the existing dual 30-inch storm sewer system along West Spreading Oaks Drive conveys the runoff from the study area to the outfall and has a combined capacity of approximately 35 cfs under gravity conditions and 70 cfs under pressure flow conditions. The proposed storm sewer system will need to be capable of conveying a 5-year design storm event of over 252 cfs. III. REVIEW OF MASTER DRAINAGE PLAN (MDP) OPTIONS A. Woodlawn Area Storm Sewer Improvements The City of Friendswood's Master Drainage Plan(MDP)targeted three possible solutions to the localized flooding problems that occur frequently at the intersections of Heritage and Dawn with Woodlawn Drive. The following are the solutions stated in the Master Drainage Plan: 1. Solution Option No. 1 -Detention Basin—In the vicinity of Woodlawn and West Shadowbend Avenue(See Exhibit Option No. 1) • "To construct a detention basin in the vicinity of Woodlawn Drive and West Shadowbend Avenue to collect and store the runoff flows before releasing to the storm sewer system. The detention basin would collect the peak flows and release the runoff through a 24-inch pipe connected to the storm sewer as the sewer pipes empty. Approximately 6 acre-feet of detention would be required for the 5-year event and 10 acre-feet for the 100- year event. This could be a temporary solution until Woodlawn Drive is repaved under the 5-year plan as proposed or kept as a permanent solution to reduce downstream flooding." The cost estimate stated in the Master Drainage Plan for this alternative, including engineering and contingencies, is $162,960. This is not a present day value and also does not reflect required land acquisition costs. This option also does not take into consideration solving the flooding problems occurring along Laurel to Woodlawn Drive down West Spreading Oaks Drive (Additive Alternative No. 1) and 4 Additive Alternative No. 2 for West Shadowbend Avenue from Laurel to Woodlawn Drive, in the amounts of$233,300 and$147,800,respectively for a total estimated construction cost of$612,260. A detail break downs of the estimates can be seen on Exhibit 3 and 4 in the Appendix. Since the MDP was prepared a new residence has been constructed just north of the sag inlet. Due to the shallowness of the existing storm drain collection system, the detention basin would need to be fairly shallow. The area available between the existing residence and West Shadowbend Avenue will produce a maximum of 2.07 acre-feet of volume based on a detention basin depth of 5 feet with 3 to 1 side slopes. In addition to the lack of available land, the time required to obtain property for a detention pond in this area may prove to be lengthy due to public resistance to the detention pond. Although the earlier estimated construction cost is considerably less, the unavailability of land adjacent to the sag area and the aesthetics and safety issues involved in a detention basin of the size required in a residential neighborhood result in this option not being a feasible option to solving the flooding problem. 2. Solution Option No. 2-Installation of New Storm Sewer Pipes and Inlets and Clearing of Coward's Creek Tributary(See Exhibit Option No. 2) The second option identified in the Master Drainage Plan is stated as follows: • "Another solution is to replace the existing storm sewers from West Shadowbend Avenue with two 60 inch storm Sewers. These can convey 60 cfs each assuming 3 fps. At the same time ditch conveyance on both sides of the street should be increased to convey a total of 30 cfs each. Flows in excess of the storm drainage system's capacity will sheet flow along the new street grades when Woodlawn Drive is improved. Until the road is improved ponding would still occur upstream,but at less frequent intervals. Additional inlets are required on the Woodlawn storm sewer west of West Shadowbend Avenue with a parallel storm sewer". 5 The cost estimate stated in the Master Drainage Plan for this option, including engineering and contingencies,is $943,986 (this is not a present day value). This concept is the preferred option to solving the problem with a few modifications providing the City had funds available and the time to address easement acquisition in the area of the tributary of Coward's Creek and the permitting that would be required to clear the tributary. This option basically will construct new storm drain pipes large enough to eliminate any flooding. The existing ditches and grate inlets along Woodlawn Drive would need to be increased to carry the additional runoff. Approximately 250 linear feet of the tributary of Coward's Creek will need to be cleaned and regraded in order to accommodate the flowline of the proposed storm sewer system. 3. Solution Option No. 3 -Installation of a Combination of New Storm Drain Pipes,Inlets and a New Drainage Ditch (See Exhibit Option No.3) • "A third solution to the flooding in this area is to convey the flows from the drainage areas north of West Shadowbend Avenue down a ditch along the back property lines between Woodlawn Drive and David Street. The proposed 48-inch and 54-inch storm sewers along West Shadowbend Avenue and Woodlawn Drive, listed in solution 2, are needed to bring the flows to the intersection. From this intersection, 2-48-inch pipes are needed to carry the flows west along West Shadowbend Avenue to the proposed ditch. The ditch will need to convey 80 cfs. A"V"ditch with a top width of 20 feet and a depth of 5 feet can convey 80 cfs at a slope of 0.003 ft/ft. The proposed storm sewer along West Spreading Oaks Drive from Woodlawn Drive to the tributary could be reduced to a single 72-inch pipe or dual 48-inch pipes." The cost estimate stated in the Master Drainage Plan for this alternative, including engineering and contingencies, is $231,160. This is not a present day value and does not include required land acquisition costs. This option also does not take into consideration solving the flooding problems occurring along Laurel to Woodlawn Drive down West Spreading Oaks Drive(Additive Alternative No. 1) and Additive Alternative No. 2 for West Shadowbend Avenue from Laurel to Woodlawn Drive, in the amounts of$233,300 6 and$147,800,respectivelyfor a total estimated construction cost of$612,260. A detail break downs of the estimates can be seen on Exhibit 3 and 4 in the Appendix. It is conceivable that the total cost to obtain the easements for the drainage ditch could reach as much as the construction cost after legal and court fees are paid. This alternative would redirect the flows entering the Woodlawn Drive system at its intersection with West Shadowbend Avenue. This would relieve the existing system along Woodlawn Drive. However,the area of the proposed drainage ditch alignment is developed and would prove to be more expensive due to land acquisition costs and more time consuming. The proposed location of the "V"ditch indicated in the Master Drainage Plan will result in significant loss of useable land because the property lines do not appear to lie in a straight line. Also the section proposed in the MDP was to have 2 to 1 side slopes which FNI believes would be unstable to erosion and would present a safety concern to those adjacent • to the drainage ditch due to the steep side slopes. FNI recommends a maximum side slope of 3-feet horizontal to 1- foot vertical. This section will result in a top width of approximately 30-feet. A strip of land 15-feet wide for access and maintenance should be obtained as part of the permanent drainage easement. A minimum 50-foot wide drainage easement should be obtained. Another 50-foot temporary construction easement should be obtained to excavate the ditch and haul the soil away. FNI believes this option is not a preferred alternative due to cost,potential delaying of the West Shadowbend Avenue project and possible opposition of this alternative by landowners along David Street 4. Alternative Solution No.4—Develop Sheet Flow Options to Reduce Risk of Flooding Along Woodlawn Drive at West Shadowbend Avenue and Develop Options to Lessen Impacts on the Tributary of Coward's Creek Using Pre-Cast Reinforced Concrete Box Sections A fourth option will evaluate surface sheet flow conditions along Woodlawn Drive at West Shadowbend Avenue and the use of pre-cast reinforced concrete box sections to reduce the depth of the storm sewer collection system along West Spreading Oaks Drive from Woodlawn Drive to the Coward's Creek tributary outfall. This option is an attempt to reduce the amount of channel cleaning/excavation along a 7 tributary of Coward's Creek near West Spreading Oaks Drive. B. ADDRESSING THE WOODLAWN DRIVE AND WEST SHADOWBEND AVENUE FLOODING PROBLEMS It is our understanding,the intent of the City is to construct a curb and gutter street along West Shadowbend Avenue from Woodlawn Drive to Sunset Drive. To provide properly drain the road right-of- . way to the paved street section, the existing street profile will need to be lowered. Lowering of West Shadowbend Drive allows runoff in excess of the capacity of the curb inlets and storm sewer system along Woodlawn Drive to sheet flow south down Woodlawn Drive and west down West Shadowbend Avenue. Additional curb inlets along Woodlawn Drive near its intersection with West Shadowbend Drive will be required to reduce the ponding at the intersection. Finished floor elevations were determined for the dwelling located on Woodlawn Drive near the sag inlets. The garage floor elevation was 28.79 and the finish floor elevation on the house was 29.43. The finish floor elevation of the dwelling at the northwest corner of Woodlawn Drive and West Shadowbend Ave. was 29.68. A maximum water surface elevation of 28.50 was set to determine the amount of runoff that would sheet flow down Woodlawn Drive and West Shadowbend Avenue during a 100-year return frequency design storm. A water surface elevation of 28.32 feet (approximately the top of curb at the Woodlawn Drive sag inlet was used to estimate the sheet flows down Woodlawn Dr. and West Shadowbend Drive for the 5-year return frequency design storm. Figure 2, Woodlawn Dr. Sag Inlet Storm Drain and Sheet Flow Diagram,below illustrates the 5-year and 100-year storm water flows into and out of the sag inlets on Woodlawn Drive. The storm drain flows were estimated using the existing 42-inch pipe under gravity and pressure flow conditions. The calculated flow was based on the flattest slope of 0.07%. Those sections of the 42-inch line having positive slopes are proposed to be removed and laid on a negative slope. 8 FIGURE 2 WOODLAWN DR.SAG INLET STORM DRAIN AND SHEET FLOW DIAGRAM Q5 =Woodlawn Dr.sheet flow =9.19 cfs Q100=Woodlawn Dr.sheet flow =25.19 cfs Q5 =W.Shadowbend Ave sheet flow=12.16 cfs Q100=W.Shadowbend Ave sheet flow=20.27 cfs ir r Q5 Water Surface Elev.=28.32 Ft Q5=47.8 cfs Q100 Water Surface Elev.=28.50 Q100=93.08 cfs Sag Inlet Top of Curb Elev=28.3 \ / I42" RCP Capacity Gravity Flow=27 cfs Pressure Flow W/W.S.Elev.@ 28.5=49.54 cfs Total Discharges Q 5 Q100 Water Surface Elevation 28.32 Ft 28.5 Ft Sheet flow down Woodlawn 9.19 cfs 25.19 cfs Sheet flow down Woodlawn Sheet flow down Shadowbend 12.16 cfs 20.27 cfs Sheet flow down Shadowbend Gravity flow down 42"RCP 27.00 cfs 49.54 cfs Pressure Flow down 42"RCP Total Peak Flow Available 48.35 cfs 95.00 cfs Total Peak Flow 47.8 cfs 93.08 cfs To maximize the amount of storm water that sheet flows down Woodlawn Drive, approximately 190 feet of Woodlawn Drive will need to be removed to the south of West Shadowbend Avenue intersection and graded to match a gutter elevation of approximately 27.86. To achieve the sheet flow conditions along Woodlawn Dr. south of West Shadowbend Avenue, the street will have to be flattened to approximately 0.1% slope. Due to the minimum slope, standard Type "C" inlets with 2 extensions are proposed at the end returns at the corners of the Woodlawn Drive and West Shadowbend Avenue. Approximately 9.19 cfs and 25.19 cfs will sheet flow down Woodlawn Drive, and 12.16 cfs and 20.27 cfs will sheet flow down West Shadowbend Avenue for the 5-year and 100-year return frequency design storms,respectively. A portion of the West Shadowbend Avenue sheet flow will discharge into the drainage ditch along David Street. A sag inlet is proposed to be constructed approximately 325 feet from the Woodlawn Dr. intersection. The sag inlets will discharge into the West Shadowbend collection system. 1 Figure 2 also indicates the distribution of the storm water flows through the existing storm drain collection system along Woodlawn Drive and the sheet 9 flows down Woodlawn Drive and West Shadowbend Ave. When the surface water ponds to an elevation of 28.50 the 42-inch storm sewer will experience pressure flow. A worst case evaluation of an estimated 100-year design storm flow near the Junior High School was analyzed to determine the approximate depth of runoff in Woodlawn Drive. If a 100-year flow of approximately 490 cfs was used for the tributary of Coward's Creek,less the runoff from the Brooke Meadows Estates area of approximately 73 cfs, less the Laurel Street flow of approximately 82 cfs at Woodlawn Drive, less 20.2 cfs that overflows to David Street down West Shadowbend from Woodlawn Drive. The runoff that will need to be carried by Woodlawn Drive drainage system is approximately 314.8 cfs. The Woodlawn Drive drainage system is composed of the following with the noted capacities: The existing storm drain pipes and street have a capacity of approximately 161 cfs and is broken down as follows: Capacity of existing 42-inch RCP under pressure flow conditions is approximately 53 cfs. Capacity of existing 36-inch RCP under pressure flow conditions is approximately 45 cfs. Capacity of Woodlawn Drive roadway section near the Junior High School @ 0.16 % slope at elevation 28.75 is approximately 63 cfs. This leaves a shortage of capacity to convey the 100-year storm by 153.8 cfs. The total future 5-year design storm entering the tributary of Coward's Creek is estimated to be approximately 252 cfs. When the existing drainage system along Woodlawn Drive is analyzed the runoff that will need to be carried by Woodlawn Drive drainage system is approximately 160 cfs. Based upon these flows the existing system should be capable of carrying the 5-year design storm. However, the system is not capable of carrying the 100-year storm within the existing right-of-way. Approximately 330 linear feet of 7-foot wide by 4-foot high reinforced concrete box pipe sloped at 0.16%with a capacity of approximately 194 cfs is required to keep the 100- year design storm within the existing street right-of-way. New curb inlets will be constructed and the existing storm drain collection system will be tied into the new reinforced concrete box pipe. The new 7' x 4' reinforced concrete box pipe would be constructed in the north bound lane of Woodlawn Drive. This RCB will connect to a proposed 6' x 3' RCB at the West Spreading Oaks Drive and Woodlawn Drive intersection. The 6' x 3' RCB will be constructed parallel to the existing dual 30-inch storm drain pipes and will discharge into a proposed 10' x 3' RCP crossing West Spreading Oaks Drive at the tributary of Coward's Creek. In an attempt to 10 preserve the existing Oak trees along West Spreading Oaks Drive, the new RCB will be constructed in the West bound lane of West Spreading Oaks Drive. Since the existing roadway will be damaged due to the construction of the RCB,two options have been estimated. The first option is to reconstruct the roadway with a 28-foot BC to BC reinforced concrete pavement section. The second option is to replace the roadway back with hot mix asphalt concrete. Detail opinions of probable cost of construction estimates are attached. The total preliminary opinion of probable cost of construction for Alternative solution No. 4 is $570,916.00 with H.M.A.C. overlay and $630,114.00 to reconstruct the roadway with a 28-foot BC-BC reinforced concrete pavement. A detailed break downs of each of the above estimates are shown in Exhibit-1 through 4 in the Appendix. C. Areas Along West Spreading Oaks Drive from Laurel to Woodlawn Drive (Additive Alternative No. 1 (See Exhibit Option No. 4) The project scope includes analyzing the existing storm sewer system along West Spreading Oaks Drive from Laurel to Woodlawn Drive. Localized flooding in areas in front of the Junior High School prompted this concern. Our analysis, confirmed the existing storm sewer system along West Spreading Oaks Drive from Laurel to Woodlawn Drive is insufficient to convey the City of Friendswood 5-year design storm event. The required capacity to convey the ultimate flow from the area is approximately 42 cfs. A 30-inch RCP storm sewer at a grade of 0.25%would convey this flow. From this point of intersection with Woodlawn Drive the proposed storm sewer system would tie into the a proposed 6 foot by 3 foot pre-cast reinforce concrete box in order to convey flows from the existing storm sewer system. New type C curb inlets with 2—5 foot extensions are recommended to replace the existing curb inlet east of the Woodlawn Drove and West Spreading Oaks Drive intersection. The remainder of the collection system can be constructed as funding becomes available or when the pavement is reconstructed. See Exhibit for proposed storm drain pipe sizes. Costs for the new inlets and connecting to the proposed RCB's are included in the West Spreading Oaks Drive out fall project. A detailed preliminary opinion of probable cost of construction for these improvements is estimated to be$233,300 as shown in Exhibit- 3 in the appendix.. 11 D. Areas Along West Shadowbend Avenue East of the Intersection of Woodlawn Drive Additive Alternative No. 2 (See Exhibit Alt. Option No. 4) Our project scope also included analyzing the existing storm sewer system along West Shadowbend Avenue from Laurel to Woodlawn Drive. Our analysis confirmed the existing storm sewer system along West Shadowbend Avenue from Laurel to Woodlawn Drive is insufficient to convey the City of Friendswood 5-year event. The required capacity to convey the ultimate flow from the area is approximately 64 cfs. A 48-inch RCP storm sewer at a grade of 0.20%would convey this flow. From the point of intersection with Woodlawn Drive the proposed storm system size continues in order to connect the parallel system. The proposed drainage improvements are recommended to be made when funding is available and when the roadway is to be reconstructed. Preliminary opinion of probable cost of construction for these improvements is estimated to be$147,800. The detailed break down is shown in Exhibit-4 in the Appendix. E. Analysis of the Existing Tributary of Coward's Creek Drainage Channel The tributary of Coward's Creek is also heavily wooded south of West Spreading Oaks Drive. The property owners have voiced concern over the clearing of the tributary creek. An evaluation to determine the capacity of the existing channel was made. The evaluation approximated the water surface elevation that would be observed under existing and future full developed conditions. The existing flooding that occurs west of West Shadowbend Avenue and Woodlawn, in effect acts like a detention pond. The existing peak flow that reaches the tributary of Coward's Creek is less than the peak flow that will be realized, after the Woodlawn drainage improvements are completed. Four cross-sections were evaluated along the tributary. Exhibit Alt. Option No. 1 indicates the approximate location of the existing channel cross- sections. The cross-sections evaluated were located approximately Stations 0+34, 0+54, 1+50, 4+75 and 7+12 from West Spreading Oaks Drive. A fifth section was evaluated at Station 6+60 feet from West Spreading Oaks Drive where the tributary channel crosses a drive to a house. Pictures of where the cross-sections were taken are shown below in Figures 2 thru 6. 12 �,.. s �""F i e s .r�,y,z#' 3 sr £ vt'f a Tom" , h r` _ - ' .a'v` k $ 0,4,..x,' "� �• Si ,�. it ,�r 1 �` §'' 'Y �e w.°r.. {{gam � s d ' • 95 s'+u 1t 1s J[""a � .tl,1y,s g ..� 1 1 { $ i 6 ,�. n{ . ` . e 11 '€``'�Okie it f . 4:„ s• � si I t ks '' \"e,", r ' t 4 a ', «' .`r a to �� -:,,-. ',, /ems i 1 i �w '�1� f r� , ,f,t..-.�.i ''' 71` ,� _i &,. ;1 % xis) .- 1 1.1' 1 :' -• i t -,,. •,, fi• r+' t >nflwl'e.x ,. * I ;,•i� g4-,`r" `, ''�-- 0--„. -' y* ,y. 1-,¢T Yr t Nye 4 a �," '" ^ a- 4 - -€`,: ma's c$`^" 'e"* * £ }` Y !�' a ' rk- ' - r I. "a—,,,,,.."..,,,..i.....- _ ,:,;.ni-_,,ka 11.‘„ -,_..I.,- t. Kj.•.« p a fv. ,..0 : WI tr.-..; w r» , i _ ,. �, ,3 Orr { f + ` .1 .� r �p° h� ...3. ... :o• tr: A.,,,.,,. . ,......, .„,- - 1.-_,,....„. .,_-_ , _ ,I,. . ,,,-- -- • . ,,,7„,„:,,,,,, ,..,,,.... .„,. . ...44 1 1• — i'*:,1-4,----"k-AI -*-k,---• --",tvt- -- '-'.,r% ''.. .'-. .---,i......- ', ','-'i.,-„,'' iC;t:) -r * ;°* � 3 «. z-Cat yr + r e r } s.'"c� fir . " _ y .. .� �J ak . a=a..r_ .-`..$c.> 4t a FIGURE 3 TRIBUTARY OF COWARD'S CREEK STATION 0+34 i i Ii 13 1 , U '�`� y' —1 �'` a S ;t^ ;u �1 rm�� r ipa� y'€ #. r t'lro' R� U` if I W. l i` '` 1 ar. F rr tk tT',# 1..t' r s.} hs€ �i t, �< •�, �4 1`r�,-'� . & ri ..-d-i* .S. '.4� - •.§-1 Y7�' ''.. }• ,:rce '-}r; µ "-- '-„,a, __ r; ,�„5 .,ram ' a-<^� r` Y .`�Y � a� 12 II FIGURE 4 TRIBUTARY OF COWARD'S CREEK STATION 0+54 'p,F,r 'sy�7' tie C ' P '• � t s �," • + '�.• -c-•,sc'�-....`.u'�' -_ . •.,t .4." V! ,S. = mac¢.r 4 '� -,.....„A 4 - —4. 'y GF ,.„ s s"�'y � ' :ei ‹, ,` .:,..A., .p* Kip "*. -- - ' 'jts nit 1 — 1 qe '. ff, -- v.; r`" ° fir' y i'' M• -� y x €, � `ski 1" ,�{•a "� i � la„�"t`x'.ry�ii �'�`v.�P � � FIGURE 5 TRIBUTARY OF COWARD'S CREEK STATION 1+50 � l - r #' .$ x ! +c3te '�tt )iS �r 4 ` C w D � " �? -( t-at —,N- "€ c,-F:"'kG ;4 " � i rg#4a• r ; ' 7 ;" ^ e b :g " k ` ^ ��.• n t 'A',e , � yt e4 M �;, � q'r�P , s k €€ 1 ter mr - c I�$RLG ' , #j ar a iY 'a"' -.r.a i; � ' c r• rr „4 r � h '4 r- ' �` ' '^ rr;m FIGURE 6 TION 4+75 TRIBUTARY OF COWARD'S CREEK STA 14 itgatr k F `"'.'�+'�tr °we# =�F'!-r�' �r t ',;., .y� 'i y �.,�k w!'(t �a `�_.: i4 `�`� �` - .�„t 'A c .r= "�n�+`'e'�' -T F'� �' � x -.K� t ▪ "� sr�SY ac.."5- s k. " v+�M ASt-S k'#`'' ti' , A+.-�'` & tiICt Y W `c.T 3� i�1 5`^� x� : • r�`'.Man., j 17.N31 baw r'" .Rz-_...ig' e `.r�. h`st+ `.:.t 3:... rzn w+,.ti, �+ ws" �1:.t FIGURE 7 TRIBUTARY OF COWARD'S CREEK STATION 6+60 a a '4t w [ ` t 1 , y- �, - c> 'yw ti c M ..€ , ivta T ggt 4 S g}mN _ �+ # � t� i is r?a ; l.. ,t v � � , 1� __ .- .� a = FIGURE 8 CONCRETE DRIVEWAY OVER DUAL 48—INCH R.C.P.'S AT STATION 6+60 15 1.7 �e i:. y# f r { 1..4 a ,� T 3 s. r T .'c �1 t .o-a '"� Z� I "may s i " ''` . ` 1�3srs +sr �a �' 'fin" ur `:�'YS r F (• L r i 1 to -pit SiT 1i4 .-" FIGURE 9 TRIBUTARY OF COWARD'S CREEK STATION 7+12 Chart A is a plot of the storm water discharges versus water surface elevations at Stations 0+54, 1+50, 4+75and 7+12. Based on the existing estimated peak discharge flow of 108 to 200 cfs, 5-year and 100-year future, the anticipated water service elevations at the above cross-sections are as follows: TABLE A Tributary of Coward's Creek Calculated Water Surface Elevation At Various Cross-Sections Station No. Closest Water Water Water Water Surface Finished Floor Surface Surface Surface Elevation @ Elevation Elevation Elevation @ Elevation 490 cfs @ 108 cfs 200 cfs @ 252 cfs (Ft) (Ft) (Ft) (Ft) (Ft) 0+54 29.33 22.0 22.5 23.0 23.9 1+50 29.33 21.3 21.9 22.2 23.0 4+75 25.44 &25.54 18.0 18.5 19.0 19.9 7+12 22.30 16.0 16.7 17.0 17.8 The finish floor elevations of the adjacent dwellings are also shown on the chart. The 5-year and 100-year design storm peak flows are plotted for existing and future developed conditions. At station 6+60 from West Spreading Oaks Drive there are two 48-inch RCP pipes under the drive. A culvert analysis was preferred on this crossing to analyze the existing and future flow conditions. Based on the above flow range of 108 to 200 cfs, the calculations indicate that the drive will not be over topped. The existing top of drive elevation is approximately 21.45'. The culvert analysis estimates the allowable headwater elevation is approximately 19.07'. The culvert analysis estimates the drive will not be topped during a 5-year design storm,but will be over topped during the 100- year design storm. 16 Chart C-1 is a plot of the rating curve for the dual 48-inch culverts which charts the discharge versus the allowable headwater and tail water elevations. The tail water cross-section was taken at Station 7+12. When the proposed Woodlawn drainage improvements are completed the estimated future developed discharge flow will be 252 cfs and 490 cfs for the 5 and 100-year design storms,respectively. With no improvements to the culver, the estimated allowable headwater elevation for the future developed discharge flows for the 5 and 100-year design storms will be approximately 20.12' and 22.47',respectively. To provide protection to the drive a third 48-inch RCP should be added. With the third 48-inch culvert pipe the headwater elevation for the 5-year storm is estimated to be approximately 18.53' with a tail water elevation of 17.1'. The 100-year design storm discharge flow will still overtop the roadway but only by 0.35 feet. The calculated headwater elevation is approximately 21.7' with a tail water elevation of 18.01'. IV. WEST SHADOWBEND AVENUE RECONSTRUCTION A. Existing Roadway (See Exhibits WSB-1 and WSB-2 Layouts) Currently,West Shadowbend Avenue is an asphalt roadway from Woodlawn Drive to Sunset Drive. The topography of the area is generally flat with roadside ditches to carry the existing drainage. The City of Friendswood intends to replace this portion of the roadway with a 28'-0" BC-BC concrete roadway section with curb and gutter. The drainage will consist of curb inlets with closed conduits instead of the roadside ditch. The primary surface drainage ways convey the storm water to the tributaries of Coward's Creek. The eastern most portion provides for sheet flow from Woodlawn with a portion of the flow discharging into the David Street drainage channel. The middle portion of West Shadowbend Avenue outfalls into an existing 42-inch storm sewer system along Sedora Drive. The westernmost portions of West Shadowbend Avenue discharges into the same tributary of Coward's Creek as the Sedora Drive storm sewer system B. Right-of-Way The existing right-of-way width along West Shadowbend Avenue is 60 feet from its Woodlawn Drive to Sunset Drive. There will be no need to extend the right-of-way width for the limits of this project. C. Land Use The land use for this area consists mainly of single-family residential homes. There is an undeveloped portion along the north right-of-way line near the intersection of Woodlawn Drive. This land is an approximate 15- 17 acre tract that is owned by the Brakebiell Trust. A member of this trust was contacted and discussed various ideas concerning the potential development of this property. The area is most likely to be residential in nature with a cluster type density. Other considerations discussed for this property varied from subdividing the property into five 3-acre tracts to sell as estate lots or sell the property outright. For the purpose of this report the proposed storm sewer system is designed to include areas of this tract 150 feet outside the right-of-way at the run-off coefficient for single family residential(C=0.55). Any runoff outside this allowance should be restricted to pre-development conditions. An equestrian center is located at the intersection of Sunset Drive and West Shadowbend Avenue. In the design of Sunset Drive an allowance in their proposed storm sewer system was calculated for this area, including areas along the north right-of-way as well. The remaining areas along the right-of-way of West Shadowbend Avenue from Woodlawn Drive to Sunset Drive consists of vacant lots, commercial developments in the form of a bus barn for Friendswood I.S.D., a church and drainage easements. D. Drainage The drainage along West Shadowbend Avenue will be divided into the following sub-areas (westernmost to easternmost): (See Exhibit WSB DA-1) • Outfall at Sunset Drive • Outfall at a tributary of Coward's Creek • Outfall at the existing 42-inch storm sewer along Sedora Drive, and • Outfall drainage channel along David Street A Type E Inlet has been designed near the intersection of Sunset Drive and West Shadowbend Avenue to receive drainage to the proposed storm system along Sunset Drive from areas along West Shadowbend approximately 460 feet west of this intersection. The required design capacity of the storm sewer pipe to convey the approximate 2.58 acres along West Shadowbend Avenue to Sunset Drive is 8.06.cfs. The minimum pipe size to convey this runoff at a velocity of 3 feet/second is a 24-inch RCP at 0.17.% grade. This area is designated as sub-area"A" on the attached drainage area map. Approximately 7.72 acres along West Shadowbend Avenue with a weighted runoff factor of 0.56 will be designated to discharge into a tributary of Coward's Creek just east of Sunset Drive. These areas are designated as sub-areas"B" and"C" on the attached drainage area map,with sub-area`B" having a cumulative area of 1.16 acres and the remaining 6.56 acres being in sub-area"C". The design runoff from sub-area"B"was calculated as being 18 4.42 cfs and a storm sewer size of 18-inch RCP with a grade of 0.25% would be required to convey this flow. Sub-area"C", design runoff is 19.35 cfs and a storm sewer size of 30-inch RCP with a grade of 0.23%would be required to convey this flow. The proposed ultimate time of concentration for sub-area "C" is 22.23 minutes, compared with an existing ultimate time of concentration of 23.19 minutes. Consequently, minimal impact to the ditch will occur. Approximately 7.03 acres along West Shadowbend Avenue with a weighted runoff factor of 0.56 will be designated to discharge into the existing 42- inch" storm sewer along Sedora Drive. These areas are designated as sub- areas "D" and "E", with sub-area"D" having a cumulative area of 1.87 acres and the remaining 5.16 acres being in sub-area"E". The design runoff from sub-area"D" is calculated as being 6.54 cfs and a storm sewer size of 18-inch RCP with a grade of 0.39% or 24-inch RCP with a grade of 0.17% would convey this flow. Concerning sub-area"E", its design runoff is 18.43 cfs and a storm sewer size of 30-inch RCP with a grade of 0.25%would convey this flow. The combined capacity discharging into the existing 42- inch storm sewer along Sedora is 24.97 cfs with a time of concentration of 15.87 minutes. The calculated 5-year capacity of the existing 42-inch storm sewer along Sedora Drive is 25.31 cfs. This storm sewer was designed to convey drainage from the Westwood Elementary School along FM 2351 to Coward's Creek. The time of concentration for the discharge from the detention pond at Westwood Elementary School to reach the existing grate inlet along West Shadowbend Drive is over 40 minutes. Therefore, the peak storm from the proposed sub-areas will not impact the capacity of the existing 42-inch storm sewer along Sedora Drive due to the variation in time of concentration between existing and proposed (see attached analysis). Approximately 12 cfs flow from Woodlawn Drive will sheet flow to a sag inlet along West Shadowbend Avenue during a 5-year design storm. A portion of the sheet flow will discharge into the drainage channel along David Street. Also approximately 4.25 acres along West Shadowbend Avenue with a weighted runoff factor of 0.52 will be designed to discharge into the 42-inch storm sewer along Sedora Drive This area is designated as sub-area"F". The design run-off from sub-area"F" is calculated as being 17.59 cfs and a storm sewer size of 30-inch with a grade of 0.20%would convey this flow. It should be noted the above capacity does not include the bus barn for the school. The runoff from this area is discharged into a detention facility located at the southwest corner of the intersection of Woodlawn and West Shadowbend Drive. The discharge from the detention facility to the existing storm sewer system along Woodlawn Drive is 3.82 cfs. 19 E. Proposed Roadway Profile of West Shadowbend Avenue From the survey information provided by C.L. Davis and Co., the proposed roadway of West Shadowbend Avenue is to be a depressed section with the exception of the areas near the tributary of Coward's Creek. This section will be slightly elevated and will require roadside ditches to drain adjoining properties along West Shadowbend Avenue. An artificial sag will need to be constructed approximately 325 west of the Woodlawn Drive and West Shadowbend Drive intersection to facilitate the sheet flowing down West Shadowbend Drive. F. Opinion of Probable Cost of Construction The opinion of probable cost of construction for the paving and drainage improvements to West Shadowbend Avenue is $1,091,300. A detailed break down of the estimate is shown on Exhibit WSB CE-5. Field design surveying has already been completed. Based on the Harris County Curve for engineering compensation the estimated basic services and additional engineering fee is estimated to be $86,400. This fee provides a 15 percent credit for this preliminary engineering report. A geotechnical soil investigations fee would be approximately$3,200. Easement acquisition and preparation is not included in the above fees. V. RECOMMENDATIONS A. WOODLAWN DRIVE DRAINAGE PROBLEM 1. Freese and Nichols, Inc. recommends that the City proceed with the design and construction of the proposed paving and drainage improvements along Woodlawn Drive and West Spreading Oaks Drive as described above in Option No. 4. It is also recommended that Additive Alternatives No. 1 and 2 be designed and bid along with the base option. This will provide the City more flexibility in determining the funds required to solve the drainage problems. Base Option Project Costs Estimated Construction Cost= $460,300 Estimated 48-Inch Culvert with headwalls= $13,000 Additive Alternative No. 1 Construction Cost=$233,300 Additive Alternative No. 2 Construction Cost= $147,800 Total Estimated Construction Cost=$854,400 Estimated Engineering Fee $70,00 Total Estimated Project Cost $911,400 20 B. WEST SHADOWBEND AVENUE PAVING AND DRAINAGE IMPROVEMENTS 1. Freese and Nichols, Inc. recommends that the City proceed with the design and construction of the paving and drainage improvements described above. The construction of the West Shadowbend Avenue and Woodlawn Drive intersection is vital to reducing the risk of flooding north of the intersection. Estimated Engineering Fee=$86,400. Estimated Construction Cost= $1,091,300 Total Project Costs =$1,177,700. 21 i EXHIBIT-1 PRELIMINARY OPINION OF PROBABLE COST OF CONSTRUCTION FOR DRAINAGE IMPROVEMENTS WEST SPREADING OAKS-OUTFALL TO WOODLAWN October 17,2003 ITEM ITEM DESCRIPTION UNIT APPROX. •UNIT ITEM QUANTITIES PRICE COST 1 Prepare Right-of-Way LS 1 $5,000.00 $5,000.00 — 2 Traffic Control LS 1 $10,000.00 $10,000.00 3 Remove Exist Asphalt Pvmt SY 505 $3.50 $1,767.50 4 Remove Exist Concrete Pvmt SY 371 $5.00 $1,855.00 - 5 Remove Exist Concrete Driveway. SY 90 $5.00 $450.00 6 Remove Exist Asphalt Driveways SY 22 $3.50 $77.00 7 Remove Exist.Dual 36"RCP LF 86 $10.00 $860.00 1 8 Roadway Excavation CY 338 $5.00 $1,690.00 9 Lime Type A Tn 10 $100.00. $1,000.00 ' 10 6"Reinf.Concrete Pvmt SY 371 $27.00 $10,017.00 11 8"Lime Stabilized Subgrade SY 424 $2.50 $1,060.00 12 H.M.A.C.Pavement Repair SY 459 $30.00 $13,770.00 13 Mono Concrete Curb LF : 250 $2.00 $500.00 14 6"Concrete Driveway SY 90 $25.00 $2,250.00 i - ! 15 4'Wide Concrete Sidewalk SY 142 $25.00 $3,550.00 16 Type C'Std.Curb Inlet W/2-Extensions EA 4 $3,600.00 $14,400.00 17 10' x 3' RCB Culvert LF 43 $475.00 $20,425.00 18 6'x 3'RCB Storm Box LF 390 $225.00 $87,750.00 19 7'x 4'RCB Storm Box LF 100 $250.00 $25,000.00 20 RC Pipe(CL III)(42 IN) LF 40 $108.00 $4,320.00 21 RC Pipe(CL III)(36 IN) LF 30 $75.00 $2,250.00 22 RC Pipe(CL III)(30IN) LF 30 $60.00 $1,800.00 23 Junction Box EA 4 $5,000.00 $20,000.00 24 Tie-in Existing Storm Sewer(24"&42") EA 6 $1,500.00 $9,000.00 ' 25 Outfall Structure(Headwall,RipRap) LS 1 $12,000.00 $12,000.00 26 Asphalt Transitions SY 93 $30.00 $2,790.00 27 Pollution Prevention LS 1 $3,000.00 $3,000.00 28 Solid Slab Sod LS 1278 $5.00 $6,390.00 - SUBTOTAL FOR WEST SPREADING OAKS-OUTFALL TO WOODLAWN $262,971.50 10%CONTINGENCIES $26,328.50 ' TOTAL FOR WEST SPREADING OAKS-OUTFALL TO WOODLAWN $289;300.00 EXHIBIT-2 • PRELIMINARY OPINION OF PROBABLE COST OF CONSTRUCTION FOR DRAINAGE IMPROVEMENTS • WOODLAWN DRIVE ON EACH SIDE OF SHADOWBEND October 17,2003 ITEM ITEM DESCRIPTION UNIT APPROX. UNIT ITEM QUANTITIES PRICE COST 1 Remove Existing Concrete Pvmt(310'x 28') SY 964 $10.00 $9,640.00 2 Remove Existing 30"RCP Pipe LF 351 $10.00 $3,510.00 3 Remove Existing 42"RCP Pipe LF 60 $15.00 $900.00 4 Remove Existing 5'Curb Inlet EA 6 $500.00 $3,000.00 5 Roadway Excavation CY 400 $5.00 $2,000.00 6 6"Cone Pvmt(310'x 28) SY 964 $27.00 $26,028.00 7 8"Lime Stabilized Subgrade SY 1,102 $2.50 $2,755.00 8 Lime Type A Tn 30 • $100.00 $3,000.00 • 9 Asphalt Transitions SY 50 $30.00 $1,500.00 • 10 RC Pipe(CL III)(42 IN) LF 60 $108.00 $6,480.00 11 RC Pipe(CL lIl)(361N) LF 351 $75.00 $26,325.00 12 Type C Std Curb InletW/1-Extension EA 2 $3,300.00 $6,600.00 13 Type C Std Curb InletW/2-Extensions EA 8 $3,600.00 $28,800.00 14 Adjust Existing STORM SEWER MANHOLE EA 2 $500.00 $1,000.00 15 Adjust Exist.Junction Box w/Grate Inlet Top EA 2 $500.00 $1,000.00 16 Adjust Existing 6"Water Line LF 150 $35.00 $5,250.00 17 Tie-in Existing Storm Sewer(30"&42") EA 10 $1,500.00 $15,000.00 18 Pollution Prevention LS 1 $3,000.00 $3,000.00 19 Traffic Control LS 1 $10,000.00 $10,000.00 SUBTOTAL FOR WOODLAWN DRIVE ON EACH SIDE OF SHADOWBEND $155,788.00 10%CONTINGENCIES $15,212.00 TOTAL FOR WOODLAWN DRIVE ON EACH SIDE OF SHADOWBEND $171,000.00 • • TOTAL FOR BASE DRAINAGE IMPROVEMENTS $460,300.00 FOR WEST SPREADING OAKS DRIVE _y EXHIBIT-3 ADDITIVE ALTERNATE NO.1 PRELIMINARY OPINION OF PROBABLE COST OF CONSTRUCTION FOR DRAINAGE IMPROVEMENTS WEST SPREADING OAKS.:LAUREL TO WOODLAWN ITEM ITEM DESCRIPTION UNIT APPROX. UNIT ITEM QUANTIFIES PRICE COST 1 'Prepare Right-of-Way LS 1 $2,000.00 $2,000.00- 2 RC Pipe(CL III)(48 IN) LF 300 $115.00 $34,500.00 3 RC Pipe(CLIII)(36IN) LF 190 $108.00 $20,520.00 4 RC Pipe(CL IIIX30 IN) LF 580 $75.00 $43,500.00 5 Type"C"Inlet EA 2 $3,600.00 $7,200.00 6 Junction Box EA 7 $5,000.00 $35,000.00 7 Tie-in Existing Storm Sewer(15"&18") EA 6 $500.00 $3,000.00 8 Remove and Replace Concret Drives SF 55 $30.00 $1,650.00 9 Remove Existing Stm.Sewer LS 1 $6,000.00 $6,000.00 10 Saw-Cut&Repair Roadway SY 1664 $30.00 $49,920.00 11 Sidewalks SF 1700 $4.00 $6,800.00 12 Site Restoration LS 1 $2,000.00 $2,000.00 • SUBTOTAL ADDITIVE ALTERNATE NO.1 LAUREL TO WOODLAWN DR. $212,090.00 10%CONTINGENCIES $21,210.00 TOTAL FOR ADDITIVE ALTERNATE NO.1-LAUREL TO WOODLAWN ALONG $233,300.00 SRPEADING OAKS DRIVE. TOTAL FOR BASE DRAINAGE IMPROVEMENTS PLUS ADDITIVE ALTERNATE NO.1 $693,600.00 FOR WEST SPREADING OAKS DRIVE EXHIBIT-4 ADDITIVE ALTERNATE NO.2 PRELIMINARY OPINION OF PROBABLE COST OF CONSTRUCTION FOR DRAINAGE IMPROVEMENTS WEST SHADOWBEND.:LAUREL TO WOODLAWN ITEM ITEM DESCRIPTION UNIT APPROX. UNIT ITEM QUANTITIES PRICE COST 1 Prepare Right-of-Way LS 1 $2,000.00 $2,000.00 2 RC PIPE(CL III)(48 IN) LF 320 $115.00 $36,800.00 3 RC PIPE(CL IlI)(42IN) LF 305 $108.00 $32,940.00 4 RC PIPE(CL III)(24 IN) LF 28 $45.00 $1,260.00 4 Type"C"Inlet EA 5 $3,600.00 $18,000.00 5 Junction Box EA 1 $5,000.00 $5,000.00 6 Tie-in Existing Storm Sewer(18"&30") EA 4 $500.00 $2,000.00 7 Remove and Replace Concret Drives SF 30 $30.00 $900.00 8 Remove Existing Stm.Sewer LS 1 $3,000.00 $3,000.00 9 Saw-Cut&Repair Roadway SY 1016 $30.00 $30,480.00 10 Site Restorationm LS 1 $2,000.00 $2,000.00 SUBTOTAL ADDITIVE ALTERNATE NO.2 LAUREL TO WOODLAWN. $134,380.00 ALONG WEST SHADOWBEND AVENUE 10%CONTINGENCIES $13,420.00 TOTAL FOR ADDITIVE ALTERNATE NO.2-LAUREL TO WOODLAWN ALONG $147,800.00 WEST SHADOWBEND AVENUE TOTAL FOR BASE DRAINAGE IMPROVEMENTS PLUS ADDITIVE ALTERNATES NO. 1 $841,400.00 AND NO.2 FOR WEST SPREADING OAKS DRIVE I EXHIBIT-5 PRELIMINARY OPINION OF PROBABLE COST OF CONSTRUCTION FOR DRAINAGE IMPROVEMENTS W SHADOWBEND AVE.: SUNSET TO WOODLAWN DR. Length:2,650' R.O.W.:60' Pavement:6"Conc.,2-lane(28'BC-BC) Sidewalk:4.0'wide,one side ITEM ITEM DESCRIPTION UNIT APPROX. UNIT ITEM QUANTITIES PRICE COST 1 *Prepare Right-of-Way AC 4 $5,000.00 $18,500.00 2 Roadway Excavation CY 8000 $5.00 $40,000.00 3 Remove Existing Pavement SY 7800 $3.50 $27,300.00 4 Culvert Removal LF 600 $5.00 $3,000.00 5 Driveway SY 400 $30.00 $12,000.00 6 Asphalt Transition SY 160 $30.00 $4,800.00 7 Block Sod SY 3000 $2.00 $6,000.00 8 Broadcast Seed AC 2 $1,200.00 $2,100.00 9 Lime Treated Subgrade(8 IN) SY 9800 $3.50 $34,300.00 10 Concrete Pavement 6 Inches SY 9100 $27.00 $245,700.00 11 Monolothic Curb LF 5300 $2.00 $10,600.00 12 Sidewalk SY 1178 $25.00 $29,450.00 13 Cement Stabilized Backfill CY 500 $30.00 $15,000.00 14 Trench Excavation Protection LF 4310 $2.00 $8,620.00 15 RC Pipe(CL III)(24 IN) LF 690 $35.00 $24,150.00 16 RC Pipe(CL III)(30 IN) LF 690 $60.00 $41,400.00 17 RC Pipe(CL IlI)(36 IN) LF 980 $75.00 $73,500.00 18 RC Pipe(CL III)(42 IN) LF 470 $108.00 $50,760.00 19 Roadside Ditch LF 950 $2.00 $1,900.00 20 Type"C"Inlet EA 12 $2,600.00 $31,200.00 21 Type"A"Inlet EA 6 $1,400.00 $8,400.00 22 Junction Box EA 1 $5,000.00 $5,000.00 23 Storm Sewer Manhole EA 8 $3,500.00 $28,000.00 24 Outfall Structure LS 2 $5,000.00 $10,000.00 25 Drainage Crossing Headwalls LS 1 $15,000.00 $15,000.00 26 Mobiliztion LS 1 $50,000.00 $50,000.00 27 Barracades,Signs&Traffic Control MO 6 . $2,000.00 $12,000.00 28 Roadway Signage LS 1 $2,000.00 $2,000.00 29 Pavement Marking LS 1 $4,000.00 $4,000.00 30 Pollution Prevention LS 1 $10,000.00 $10,000.00 31 8"Sanitary Sewer LF 1800 $35.00 $63,000.00 32 10"Sanitary Sewer LF 660 $40.00 $26,400.00 33 Sanitary Sewer Manholes EA 9 $2,000.00 $18,000.00 34 Remove Existing San.Sewer&Manhole LF 2400 $5.00 $12,000.00 35 6"Water Line Removal&Replacement LF 200 $40.00 $8,000.00 36 Water Line&Sanitary Sewer Services(Budget) LS 1 $15,000.00 $15,000.00 37 Misc.Site Restoration Incl.Mail Boxes Walks,Landscapes LS 1 $25,000.00 $25,000.00 SUBTOTAL W SHADOWBEND AVE.: SUNSET TO WOODLAWN DR. $992,080.00 10%CONTINGENCIES $99,220.00 TOTAL W SHADOWBEND AVE.: SUNSET TO WOODLAWN DR. $1,091,300.00 TABLE DA-1 SUMMARY City of Friendswood DESIGN FLOW CALCULATION SUMMARY TABLE-RATIONAL METHOD 10/02/03 1:41 PM filename:Drainage Area Calc.xls FLOW DESIGN DESIGN CALCULATION DRAINAGE OVERLAND CHANNELIZED TIME OF RAINFALL C- FLOW POINT DESCRIPTION AREA FLOW TIME FLOW TIME CONCENTRATION INTENSITY FACTOR RATE IDENTIFICATION (ACRES) (MIN.) (MIN.) (MIN) (IN/HR) (CFS) Total Existing Drainage Area TABLE I Q5 111.260 10 31.5 41.5 3.71 0.58 238.55 TABLE 1-A Q100 111.160 10 31.5 41.5 5.77 0.58 463.75 Total Developed Flow TABLE 2 Q5 111.160 10 31.5 41.5 3.71 0.61 252.07 TABLE 2-A Q100 111.160 10 31.5 41.5 5.77 0.61 490,04 Detention Area North TABLE 3 Q5 21.730 10 31.5 41.5 3.71 0.59 47.88 TABLE 3-A Q100 21.730 10 31.5 41.5 5.77 0.59 93.08 Brooke Meadows TABLE 4 Q5 22.500 10 31.5 41.5 3.71 0.45 37.56 TABLE 4-A - Q100 22.500 10 31.5 41.5 5.77 0.45 73.03 Woodlawn Area to Coward Creek TABLE 5 f Q5 86.660 10 31.5 41.5 3.71 0.65 214.51 TABLE 5-A l Q100 88.660 10 31.5 41.5 5.77 0.65 417.02 SUBAREA:LAUREL&SPREADING OAKS TABLE 6 I Q5 3.370 10 7.39 17.4 6.12 0.75 15.52 TABLE 6-A l Q100 3.370 10 . 7.39 17.4 9.17 0.75 29.06 Laurel&Spreading Oaks Reach 2 Conditions TABLE 7 Q5 4.230 10 9.39 19.4 5.78 0.72 17.59 TABLE 7-A Q100 4.230 10 9.39 19.4 8.7 _ 0.72 33.10 Laurel to Woodlawn Drive TABLE 8 Q5 18.590 10 32.44 42.4 3.96 0.57 42.18 TABLE 8-A Q100 18.590 10 32.44 42.4 6.13 0.57 81.63 TABLE LU-1 City of Friendswood Summary of Existing and Developed Area Conditions Woodlawn Drainage Study filename3hainage Area Calc.xls • 10/17/03 10:28 AM Total Area= 4,842,129.60 sq.ft = 111.160 acres Eiistine Conditions: Proposed Conditions: Undeveloped 971,388 sq.ft. Undeveloped 586,753 sq.ft. = 22.30 acres = 13.47 acres Single Family 1,116,878 sq.ft. Single Family 1,501,078 sq.ft. = 25.64 acres = 34.46 acres Mobile Homes 324,958 sq.ft. Mobile Homes 324,958 sq.ft = 7.46 acres = 7.46 acres Neighborhood Commerical 838,530 sq.ft. Neighborhood Commercial 838,530 sq.ft. = 19.25 acres = 19.25 acres Pavement 304,920 sq.ft. Pavement 257,004 sq.ft. = 7.00 acres 5.90 acres • Ditches&ROW 305,356 sq.ft. Ditches&ROW 353,707 sq.ft. . = 7.01 acres = 8.12 acres Estate Lots 980,100 sq.ft. Estate Lots 980,100 sq.ft. 22.50 acres = 22.50 acres Total Existing= 4,842,130 sq.ft. Total Proposed= 4,842,130 sq.ft. = 111.1600 acres = 111.1600 acres Brooke Meadows Estate Lots Woodlawn Drainage Area to Coward Ck Undeveloped 0 sq.ft. Undeveloped 586,753 sq.ft. = 0.00 acres = 13.47 acres Single Family 0 sq.ft Single Family 1,501,078 sq.ft. = 0.00 acres = 34.46 acres Mobile Homes 0 sq.ft. Mobile Homes 324,958 sq.ft. 1 = 0.00 acres = 7.46 acres i Neighborhood Commerical 0 sq.ft. Neighborhood Commercial 838,530 sq.ft = 0.00 acres = 19.25 acres Pavement 0 sq.ft. Pavement 257,004 sq.ft. = 0.00 acres = 5.90 acres Ditches&ROW 0 sq.ft Ditches&ROW 353,707 sq.ft. = 0.00 acres = 8.12 acres Estate Lots 980,100 sq.ft. Estate Lots 0 sq.ft. = 22.50 acres = 0.00 acres Total= 980,100 sq.ft. Total= 3,862,030 sq.ft. = 22.5000 acres = 88.6600 acres Detention Area W&S of Woodlawn Detention Area W&S of Woodlawn Developed Undeveloped Undeveloped 621,601 sq.ft. Undeveloped 621,601 sq.ft. ' 14.27 acres = 14.27 acres Single Family 0 sq.ft. Single Family 0 sq.ft = 0.00 acres = 0.00 acres Mobile Homes 324,958 sq.ft. Mobile Homes 324,958 sq.ft. = 7.46 acres = 7.46 acres Neighborhood Commerical 0 sq.ft. Neighborhood Commerical 0 sq.ft. = 0.00 acres - = 0.00 acres Pavement 0 sq.ft. Pavement 0 sq.ft. = 0.00 acres = 0.00 acres Ditches&ROW 0 sq.ft. Ditches&ROW 0 sq.ft. = 0.00 acres = 0.00 acres Estate Lots 0 sq.ft. Estate Lots 0 sq.ft. 0.00 acres = 0.00 acres Total= 946,559 sq.ft. Total= 946,559 sq.ft. = 21.7300 acres = 21.7300 acres 1 TABLE LU-2 City of Friendswood Summary of Existing and Developed Area Conditions Woodlawn Drainage Study filename:Drainage Area Calc.xls 10/02/03 12:22 PM Total Area= 146,795.00 sq.ft. = 3.370 acres Laurel&Spreading Oaks Conditions Laurel&Spreading Oaks Reach 2 Conditions - Undeveloped 0 sq.ft. Undeveloped 0 sq.ft_ = 0.00 acres = 0.00 acres Single Family 52,707 sq.& Single Family 84,942 sq.ft. = 1.21 acres = 1.95 acres Mobile Homes 0 sq.ft Mobile Homes 0 sq.ft. = 0.00 acres = 0.00 acres Neighborhood Commerical 71,438 sq.ft. Neighborhood Commercial 74,923 sq.ft. = 1.64 acres = 1.72 acres Pavement 10,454 Pavement 11,326 sq.ft. = 0.24 acres = 0.26 acres Ditches&ROW 12,196 sq.ft. Ditches&ROW 13,068 sq.ft. i = 0.28 acres = 0.30 acres Estate Lots 0 sq.ft. Estate Lots 0 sq.& = 0.00 acres = 0.00 acres •i Total Existing= 146,795 sq.ft. Total Proposed= 184,259 sq.ft. = 3.3699 acres = 4.2300 acres Laurel to Woodlawn Drive -.I Undeveloped 0 sq.ft. Undeveloped 0 sq.ft = 0.00 acres = 0.00 acres Single Family 439,084 sq.ft. Single Family 0 sq.ft. = 10.08 acres = 0.00 acres Mobile Homes 0 sq.ft. Mobile Homes 0 sq.ft. = 0.00 acres = 0.00 acres Neighborhood Commerical 223,027 sq.ft. Neighborhood Commercial 0 sq.ft_ = 5.12 acres = 0.00 acres ' Pavement 68,825 •sq.ft. Pavement 0 sq.ft. 1.58 acres = 0.00 acres Ditches&ROW 78,844 sq.ft. Ditches&ROW 0 sq.ft. • = 1.81 acres = 0.00 acres Estate Lots 0 sq.ft. Estate Lots 0 sq.ft. = 0.00 acres = 0.00 acres i Total= 809,780 sq.ft. Total= 0 sq.ft. = 18.5900 acres = 0.0000 acres TABLE 1 DETERMINATION OFDESIGNDISCHARGE SUBAREA:EXISTING 5 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 111.160 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (fl/ft)for vel.(ft/sec) Col.A/(60xCo1 C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.0 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 3 2350 3.0 2350 /60x 3 = 13.06 4 /60x = Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION i Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) i Design Duration=Tc(min.)= 41.5 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 3.7 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B i 1 Pavement 7.000 0.95 0.063 x 0.95 = 0.06 2 Neighbor-Commercial 19.250 0.95 0.173 x 0.95 = 0.16 3 Undeveloped 22.300 0.30 0.201 x 0.30 = 0.06 4 Single Family 25.640 0.55 0.231 x 0.55 = 0.13 5 Mobile Home Resid 7.460 0.85 0.067 x 0.85 = 0.06 6 Ditches&ROW 7.010 0.30 0.063 x 0.30 = 0.02 7 Estate Lots 22.500 0.45 0.202 x 0.45 = 0.09 Composite C Value for total discharge area= 0.58 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(inhu)x Area(acres)= 0.58 x 3.71 x 111.160 = 238.55 filename:Drainage Area Calc.xls TABLE 1-A DETERMINATION OFDESIGN DISCHARGE SUBAREA:EXISTING 100 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 111.160 OVERLAND FLOW TIME(OR TIME TO CIIANNEI.I7.ATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/see) Col.A/(60xCol C.) for surface(It) conduit for conduit 1 1225 3.00 1225 /60x 3 = 6.81 2 2100 3.00 2100 /60x 3 = 11.67 3 2350 3.00 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 • TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min)= 41.5 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 5.8 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 7.000 0.95 0.063 x 0.95 = 0.06 2 Neighbor-Commercial 19.250 0.95 0.173 x 0.95 = 0.16 3 Undeveloped 22.300 0.30 0.201 x 0.30 . = 0.06 4 Single Family 25.640 0.55 0.231 x 0.55 = 0.13 5 Mobile Home Resid 7.460 0.85 0.067 x 0.85 = 0.06 6 Ditches&ROW 7.010 0.30 0.063 x 0.30 = 0.02 7 Estate Lots 22.500 0.45 0.202 x 0.45 = 0.09 Composite C Value for total discharge area= 0.58 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 1.25 x 0.58 x 5.77 x 111.160 = 463.75 filename:Drainage Area Calc.xls TABLE 2 DETERMINATION OF DESIGN DISCHARGE SUBAREA:DEVELOPED 5 YR.STORM 10/02/03 • DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 111.160 OVERLAND FLOW TIME(OR TIME TO CHANNELTLATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (fl/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 • TIME OF CHANNELIZED FLOW A. B. C. I Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(fl/sec) Co1.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.00 1225 /60x 3 = _ 6.81 2 2100 3.00 2100 /60x 3 _ = 11.67 3 2350 3.00 _ 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 I DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 5.0 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 3.7 C FACTOR(C) I A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 5.900 0.95 0.053 x 0.95 - 0.05 I 2 Neighbor-Commercial 19.250 0.95 0.173 x 0.95 = 0.16 3 Undeveloped 13.470 0.46 0.121 x 0.46 = 0.06 4 Single Family 34.460 0.55 0.310 x 0.55 = 0.17 5 Mobile Home Resid 7.460 0.85 0.067 x 0.85 = 0.06 6 Ditches&ROW 8.120 0.30 0.073 x 0.30 = •0.02 7 Estate Lots 22.500 0.45 0.202 x 0.45 = 0.09 Composite C Value for total discharge area= 0.61 I DESIGN FLOW RATE Application of Rational Formula: i Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) I Q(cfs)=C x i(in/hr)x Area(acres)= 0.61 x 3.71 x 111.160 = 252.07 • filename:Drainage Area Calc.xls . 1 • TABLE 2-A DETERMINATION OF DESIGN DISCHARGE SUBAREA:DEVELOPED 100 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 111.160 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) • A. B. C. ' Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(fVsec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 _ = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) CoI.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.0 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 3 2350 3.0 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 41.5 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 5.8 C FACTOR(C) • A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B I Pavement 5.900 0.95 0.053 x 0.95 = 0.05 2 Neighbor-Commercial 19.250 0.95 _0.173 x 0.95 = 0.16 3 Undeveloped 13.470 0.46 0.121 x 0.46 = 0.06 4 Single Family 34.460 0.55 0.310 x 0.55 = 0.17 5 Mobile Home Resid 7.460 0.85 0.067 k 0.85 = 0.06 6 Ditches&ROW 8.120 0.30 0.073 x 0.30 = 0.02 7 Estate Lots 22.500 0.45 0.202 x 0.45 = 0.09 Composite C Value for total discharge area= 0.61 DESIGN FLOW RATE ' Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 1.25 x 0.61 x 5.77 x 111.160 = 490.04 1 1 filename:Drainage Area Calc.xls TABLE 3 DETERMINATION OFDESIGNDISCHARGE DETENTION AREA NORTH SUBAREA:DEVELOPED 5 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 21.730 OVERLAND FLOW TIME(OR TIME TO CHANNELJZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 • 4 0 /60x 0 = 0.00 Total overland flow time(min) = 10.00 1 TIME OF CHANNELIZED FLOW A. B. C. ' ' - Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.0 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 3 2350 3.0 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 41.5 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 3.71 C FACTOR(C) . A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 0.000 0.95 0.000 x 0.95 = 0.00 2 Neighbor-Commercial 0.000 0.95 0.000 x 0.95 = 0.00 3 Undeveloped 14.270 0.46 0.657 x 0.46 = 0.30 • 4 Single Family 0.000 0.55 0.000 x 0.55 = 0.00 • 5 Mobile Home Resid 7.460 0.85 0.343 x 0.85 = 0.29 6 Ditches&ROW 0.000 0.30 0.000 x 0.30 = 0.00 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 • Composite C Value for total discharge area= 0.59 : DESIGN FLOW RATE Application of Rational Formula: • Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 0.59 x 3.71 x 21.730 = 47.88 filename:Drainage Area Calc.xls TABLE 3-A DETERMINATION OF DESIGN DISCHARGE DETENTION AREA NORTH SUBAREA:DEVELOPED 100 YR STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 21.730 OVERLAND FLOW TIME(OR TIME TO CHANNELTGATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Co1.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. 1 Channelized Average slope Time of Channelized flow(minutes) . flow distance (ft/ft)for vel.(ft/sec) Co1.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.0 _ 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 3 2350 3.0 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 i TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 41.5 Storm Frequency= 100 Design Rainfall Intensity(inlhr)= 5.77 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 0.000 0.95 0.000 x 0.95 = 0.00 2 Neighbor-Commercial 0.000 0.95 0.000 x 0.95 = 0.00 3 Undeveloped 14.270 0.46 _ 0.657 x 0.46 = 0.30 4 Single Family 0.000 0.55 0.000 x 0.55 = 0.00 5 Mobile Home Resid 7.460 0.85 0.343 x 0.85 = 0.29 6 Compacted Gravel 0.000 0.30 0.000 x 0.30 = 0.00 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.59 DESIGN FLOW RATE Application of Rational Formula: . Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(inlhr)x Area(acres)= 1.25 x 0.59 x 5.77 x 21.730 = 93.08 filename:Drainage Area Calc.xls TABLE 4 DETERMINATION OF DESIGN DISCHARGE Brooke Meadows Estate Lots Flow to Coward Creek Tributary SUBAREA:Existing 5 YR.STORM l0/17/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 22.500 • OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCo1 C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 _ 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) CoLA/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.0 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 3 2350 3.0 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) • Design Duration=Tc(min.)= 41.5 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 3.71 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 0.000 0.95 0.000 x 0.95 = 0.00 Neighbor-Commercial 0.000 0.95 0.000 x 0.95 = 0.00 • 3 Undeveloped 0.000 0.46 0.000 x 0.46 = 0.00 4 Single Family 0.000 0.55 0.000 x 0.55 = 0.00 5 Mobile Home Resid 0.000 0.85 0.000 x 0.85 = 0.00 6 Ditches&ROW 0.000 0.30 0.000 x 0.30 = 0.00 7 Estate Lots 22.500 0.45 1.000 x 0.45 = 0.45 • Composite C Value for total discharge area= 0.45 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 0.45 x 3.71 x 22.500 = 37.56 filename:Drainage Area Calc.xls TABLE 4-A DETERMINATION OF DESIGN DISCHARGE Brooke Meadows Estate Lots Flow to Coward Creek Tributary SUBAREA:DEVELOPED 100 YR STORM 10/02/03 DRAINAGE AREA(A) ' Critical contributing drainage area to point of interest(acres)_ 22.500 OVERLAND FLOW TIME(OR TIME TO CHANNEL3ZATION OF FLOW) ' A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 300 0.050 0.5 300 /60x 0.5 = 10.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00_ Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW . A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.0 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 3 2350 3.0 2350 /60x 3 = 13.06 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION i Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 41.5 From Figure 4-2 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 5.77 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 0.000 0.95 0.000 x 0.95 = 0.00 ! 2leighbor-Commercial 0.000 0.95 0.000 x 0.95 = 0.00 3 Undeveloped 0.000 0.46 0.000 x 0.46 = 0.00 4 Single Family 0.000 0.55 0.000 x '0.55 = 0.00 5 Mobile Home Resid 0.000 0.85 0.000 x 0.85 = 0.00 j 6 Ditches&ROW 0.000 0.30 0.000 x 0.30 = 0.00 7 Estate Lots 22.500 0.45 1.000 x 0.45 = 0.45 Composite C Value for total discharge area= 0.45 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 1.25 x 0.45 x 5.77 x 22.500 = 73.03 filename:Drainage Area Calc.xls TABLE 5 DETERMINATION OF DESIGN DISCHARGE Woodlawn Drainage Area to Coward Ck SUBAREA:DEVELOPED 5 YR.STORM 10/02/03 . . DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 88.660 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) • A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 , 0 /60x 0 = 0.00 • Total overland flow time(min.) = 10.00 I TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) 1 flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 1225 3.00 1225 /60x 3 = 6.81 ' 2 2100 3.00 2100 /60x 3 = 11.67 3 2350 3_.00 2350 /60x 3 = 13.06 4 0 /60x 0 = 0 Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min)= 41.5 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 3.71 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 ,. Pavement 5.900 0.95 0.067 x 0.95 = 0.06 i 2 Veighbor-Commercial 19.250 0.95 0.217 x 0.95 = 0.21 3 Undeveloped 13.470 0.46 0.152 x 0.46 = 0.07 4 -Single Family _ 34.460 0.55 0.389 x 0.55 = 0.21 5 Mobile Home Resid 7.460_ _ 0.85 0.084 x 0.85 = 0.07 • 6 Ditches&ROW 8.120 0.30 0.092 x 0.30 = 0.03 7 - Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.65 • DESIGN FLOW RATE Application of Rational Formula: • Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 0.65 x 3.71 x 88.660 = 214.51 filcname:Drainage Area Calc.xls TABLE 5-A DETERMINATION OFDESIGNDISCHARGE Woodlawn Drainage Area to Coward Ck SUBAREA:DEVELOPED 100 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 88.660 • OVERLAND FLOW TIME(OR TIME TO CI]ANNELIZAITION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCo1 C.) surface(ft) surface for surface 1 0.0 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) Col.A/(6oxCol C.) for surface(ft) conduit for conduit 1 1225 3.0 1225 /60x 3 = 6.81 2 2100 3.0 2100 /60x 3 = 11.67 ' 3 2350 3.0 2350 • /60x 3 = 13.06 4 0 /60x 0 = 0.00 ' Total overland flow time(min.) = 31.53 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 41.53 DESIGN RAINFALL INTENSITY(i) ' Design Duration=Tc(min.)= 41.5 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 5.77 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 5.900 0.95 0.067 x 0.95 = 0.06 2:Teighbor-Commercial 19.250 0.95 . 0.217 x 0.95 = 0.21 3 Undeveloped 13.470 0.46 0.152 x 0.46 = 0.07 4 Single Family 34.460 0.55 0.389 x 0.55 = 0.21 5 Mobile Home Resid 7.460 0.85 0.084 x 0.85 = 0.07 6 Ditches&ROW 8.120 0.30 0.092 x 0.30 _ = 0.03 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.65 DESIGN FLOW RATE Application of Rational Formula: I Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 1.25 x 0.65 x 5.77 x 88.660 = 417.02 filename:Drainage Area Calc.xls TABLE 6 DETERMINATION OFDESIGNDISCHARGE SUBAREA:LAUREL&SPREADING OAKS 10/02/03 5-YR DESIGN STORM DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 3.370 OVERLAND FLOW TIME(OR TIME TO CHANNELPLATION OF FLOW) • A. B. C. Overland flow Average slope Overland flow time for surface(minutes) , distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x = 0.00 4 0 - /60x 0 = 0.00 Total overland flow time(min.) = 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) ! flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 900 3.0 900 /60x 3 = 5.00 2 400 3.0 400 /60x 3 = 2.22 3 30 3.0 30 /60x 3 = 0.17 4 3 0 /60x 3 = 0.00 Total overland flow time(min.) = 7.39 1 TIME OF CONCENTRATION • Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 17.39 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 17.4 ' • Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 6.1 • C FACTOR(C) A B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 0.240 0.95 0.071 x 0.95 = 0.07 2 Neighbor-Commercial 1.640 0.95 0.487 x 0.95 = 0.46 3 Undeveloped 0.000 0.30 0.000 x 0.30 = 0.00 • 4 Single Family - 1.210 0.55 0.359 x 0.55 = 0.20 5 Mobile Home Resid 0.000 0.85 0.000 x 0.85 = 0.00 6 Ditches&ROW 0.280 0.30 0.083 x 0.30 = 0.02 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.75 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 0.75 x 6.12 x 3.370 = 15.52 0 • TABLE 6-A DETERMINATION OFDESIGN DISCHARGE SUBAREA:LAUREL&SPREADING OAKS SUBAREA:EXISTING 100 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 3.370 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 • 0 /60x 0 = 0.0b 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 ' TIME OF CHANNELTLED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 900 3.0 900 /60x 3 = 5.00 2 400 3.0 400 /60x 3 = 2.22 3 30 3.0 30 /60x 3 = 0.17 4 3 0 /60x 3 = 0.00 • Total overland flow time(min.) = 7.39 i TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 17.39 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 17.4 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 9.2 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B I Pavement 0.240 0.95 0.071 x 0.95 = 0.07 2 Neighbor-Commercial 1.640 0.95 0.487 x 0.95 = 0.46 3 Undeveloped 0.000 0.30 0.000 x 0.30 = 0.00 4 - Single Family 1.210 0.55 0.359 x 0.55 _ = 0.20 5 Mobile Home Resid 0.000 0.85 0.000 x 0.85 = 0.00 i 6 Ditches&ROW 0.280 0.30 0.083 x 0.30 = 0.02 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 • Composite C Value for total discharge area= 0.75 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 1.25 x 0.75 x 9.17 x 3.370 = 29.06 ' 0 TABLE 7 DETERMINATION OF DESIGN DISCHARGE Laurel&Spreading Oaks Reach 2 Conditions SUBAREA:EXISTING 5 YR.STORM • 10/02/03 - DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 4.230 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Co1.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 _ = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(ruin.) = 10.00 TIME OF CHANNELTLED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) j flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 900 3.0 900 /60x 3 = 5.00 2 400 3.0 400 /60x 3 = 2.22 • 3 30 3.0 30 /60x 3 = 0.17 4 360 3.00 360 /60x 3 = 2.00 Total overland flow time(min) = 9.39 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 19.39 DESIGN RAINFALL INTENSITY(i) , Design Duration=Tc(min.)= 19.4 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 5.8 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 I Pavement 0.260 0.95 0.061 x 0.95 = 0.06 2 Neighbor-Commercial 1.720 0.95 0.407 x 0.95 = 0.39 3 Undeveloped 0.000 0.46 0.000 x 0.46 = 0.00 . 4 Single Family 1.950 0.55 _ 0.461 x 0.55 = 0.25 5 Mobile Home Resid 0.000 0.85 0.000_ x 0.85 = 0.00 6 Ditches&ROW 0.300 _ _0.30 0.071 x 0.30 = 0.02 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 • Composite C Value for total discharge area= 0.72 I DESIGN FLOW RATE Application of Rational Formula: 1 i Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 0.72 x 5.78 x 4.230 = 17.59 0 • TABLE 7-A DETERMINATION OF DESIGN DISCHARGE Laurel&Spreading Oaks Reach 2 Conditions SUBAREA:DEVELOPED 100 YR.STORM 10/02/03 DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 4.230 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) • surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 /60x 0 = 0.00 3 /60x 0 = 0.00 4 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 I TIME OF CHANNEI.I7.FD FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance . (ft/ft)for vel.(ft/sec) Col.A/(60xCoI C.) ' for surface(ft) conduit for conduit 1 900 3.0 900 /60x 3 = 5.00 2 400 3.0 400 /60x 3 = 2.22 3 30 3.0 30 /60x 3 = 0.17 4 360 3.0 360 /60x 3 = 2.00 Total overland flow time(min.) = 9.39 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 19.39 DESIGN RAINFALL INTENSITY(i) Design Duration=Tc(min.)= 19.4 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 8.7 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 0.260 0.95 0.061 x 0.95 = 0.06 2 Neighbor-Commercial 1.720 0.95 0.407 x 0.95 = 0.39 3 Undeveloped 0.000 0.46 0.000 x 6.46 = 0.00 4 Single Family 1.950 0.55 0.461 x 0.55 = 0.25 5 Mobile Home Resid 0.000 0.85 _ 0.000 x 0.85 = 0.00 6 Ditches&ROW 0.300 0.30 0.071 x 0.30 = 0.02 i 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.72 DESIGN FLOW RATE Application of Rational Formula: i Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/r)x Area(acres)= 1.25 x 0.72 x 8.70 x 4.230 = 33.10 0 1 TABLE 8 1 DETERMINATION OF DESIGN DISCHARGE Laurel to Woodlawn Drive SUBAREA:DEVELOPED 5 YR.STORM 10/02/03 - DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 18.590 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 _ /60x 0 = 0.00 2 0 /60x 0 = 0.00 1 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 Total overland flow time(min.) = 10.00 1 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) for surface(ft) conduit for conduit 1 2000 3.0 2000 /60x 3 = 11.11 2 1900 3.0 •-1900 /60x 3 = 10.56 3 1700 3.0 1700 /60x 3 = 9.44 4 240 3.0 240 /60x. 3 = 1.33 Total overland flow time(min.) = 32.44 TIME OF CONCENTRATION Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 42.44 DESIGN RAINFALL INTENSITY(i) I Design Duration=Tc(min.)= 42.4 Storm Frequency= 5 Design Rainfall Intensity(in/hr)= 3.96 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 1.580 0.95 0.073 x 0.95 = 0.07 2 Neighbor-Commercial 5.120 0.95 0.236 x 0.95 = 0.22 3 Undeveloped 0.000 0.46 0.000 x 0.46 = 0.00 4 Single Family 10.080 0.55 0.464 x . 0.55 = 0.26 5 Mobile Home Resid 0.000 0.85 0.000 x 0.85 = 0.00 6 Ditches&ROW 1.810 0.30 0.083 _ x 0.30 = 0.02 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.57 1 DESIGN FLOW RATE Application of Rational Formula: ' Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) i Q(cfs)=C x i(in/br)x Area(acres)= 0.57 x 3.96 x 18.590 = 42.18 0 - TABLE 8-A DETERMINATION OF DESIGN DISCHARGE Laurel to Woodlawn Drive SUBAREA:DEVELOPED 100 YR.STORM 10/17103 - DRAINAGE AREA(A) Critical contributing drainage area to point of interest(acres)= 18.590 OVERLAND FLOW TIME(OR TIME TO CHANNELIZATION OF FLOW) A. B. C. Overland flow Average slope Overland flow time for surface(minutes) distance for (ft/ft)for vel.(ft/sec) Col.A/(60xCol C.) surface(ft) surface for surface 1 0 /60x 0 = 0.00 2 0 /60x 0 = 0.00 3 0 /60x 0 = 0.00 4 0 /60x 0 = 0.00 • Total overland flow time(min.) = _ 10.00 TIME OF CHANNELIZED FLOW A. B. C. Channelized Average slope Time of Channelized flow(minutes) flow distance (ft/ft)for vel.(ft/sec) CoI.A/(60xCo1 C.) for surface(ft) conduit for conduit 1_ 2000 3.0 2000 /60x 3 = 11.11 2 1900 3.0 1900 /60x 3 = 10.56 3 1700 3.0 1700 /60x 3 = 9.44 4 240 3.0 240 /60x 3 = 1.33 Total overland flow time(min.) = 32.44 TIME OF CONCENTRATION i Tc=Overland Flow Time+Time to Channelized Flow(minutes)= 42.44 DESIGN RAINFALL INTENSITY(i) I Design Duration=Tc(min.)= 42.4 Storm Frequency= 100 Design Rainfall Intensity(in/hr)= 6.13 C FACTOR(C) A. B. Land Use Area(acres) C value for Component C value for land use land use (Col.A/Total area)x Col.B 1 Pavement 1.580 0.95 0.073 x 0.95 = 0.07 2 Neighbor-Commercial 5.120 0.95 0.236 x 0.95 = 0.22 3 Undeveloped 0.000 0.46 0.000 x 0.46 = 0.00 4 Single Family 10.080 0.55 0.464 x 0.55 = 0.26 5 Mobile Home Resid 0.000 0.85 0.000 x 0.85 = 0.00 6 Ditches&ROW 1.810 0.30 0.083 x 0.30 = 0.02 7 Estate Lots 0.000 0.45 0.000 x 0.45 = 0.00 Composite C Value for total discharge area= 0.57 DESIGN FLOW RATE Application of Rational Formula: Design Discharge(Q)=Composite C x Design Rain Intensity(i)x Area(A) Q(cfs)=C x i(in/hr)x Area(acres)= 1.25 x 0.57 x 6.13 x 18.590 = 81.63 0 • Figure 1 Rainfall Ia�Fx`2 \:•��. . ,' :s p ' s:,---,, "z � � o \ < 'v \ a \ �\ 'a, ,ea .` '� � ' >� , ' P W L �ntensity Duration Curves . 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Woodlawn Street Flow Capacity 192 Ft South of Shadowbend Worksheet for Irregular Channel Project Description Worksheet Woodlawn xsect 192 south of st Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 001600 ft/ft • Water Surface Elev; 28.32 ft Options Current Roughness Methc)ved Lotter's Method Open Channel Weighting bved Lotter's Method Closed Channel Weightinc Horton's Method Results Mannings Coeffic 0.014 Elevation Range 7.86 to 28.98 Discharge 9.19 cfs Flow Area 6.2 ft2 Wetted Perimeter 30.59 ft Top Width 30.19 ft Actual Depth 0.46 ft Critical Elevation 28.24 ft Critical Slope 0.005125 ft/ft Velocity 1.49 ft/s Velocity Head 0.03 ft • Specific Energy 28.35 ft Froude Number 0.58 Flow Type Subcritical Calculation Messages: Flow is divided. • Roughness Segments Start End Mannings Station Station Coefficient 0+00 0+15 0.035 0+15 0+56 0.013 0+56 0+68 0.035 Natural Channel Points Station Elevation (ft) (ft) 0+00 28.97 0+15 28.38 0+26 28.40 0+27 27.93 0+41 28.38 0+55 27.86 0+56 28.36 0+59 28.40 Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.1m2 Freese&Nichols Inc FlowMasterv6.1 [61401 10/02/03 02:18:26 PM 0 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 2 Woodlawn Street Flow Capacity 192 Ft South of Shadowbend Worksheet for Irregular Channel Natural Channel Points Station Elevation (ft) (ft) 0+62 28.00 0+68 28.98 • Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [6140] 10/02/03 02:18:26 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 2 Woodlawn Xsect 192 ft south of Shadowbend Cross Section for Irregular Channel Project Description Worksheet Woodlawn xsect 192 south of sl Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficiei 0.014 Slope 0.001600 ft/ft Water Surface Elev 28.50 ft Elevation Range '.86 to 28.98 Discharge 25.19 cfs 29.0 . 28.40 . 27.80 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 V:4.0\ H:1 NTS Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 09/25/03 04:44:20 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203)755-1666 Page 1 of 1 ' Woodlawn Xsect 192 ft South of Shadowbend Rating Table for Irregular Channel' Water Discharge Velocity Flow Wetted Top Surface (cfs) (ft/s) Area Perimeter Width Elevation (12) (ft) (ft) (ft) 28.26 6.10 1.35 4.5 26.04 25.70 28.27 6.56 1.38 4.8 26.80 26.44 28.28 7.04 1.40 5.0 27.56 27.19 28.29 7.55 1.42 5.3 28.32 27.94 28.30 8.07 1.44 5.6 29.08 28.69 28.31 8.62 1.47 5.9 29.83 29.44 28.32 9.19 1.49 6.2 30.59 30.19 28.33 9.79 1.51 6.5 31.35 30.93 28.34 10.41 1.53 6.8 32.11 31.68 28.35 11.05 1.55 7.1 32.87 32.43 28.36 11.72 1.57 7.5 33.63 33.18 28.37 12.37 1.59 7.8 35.24 34.79 • 28.38 13.05 1.60 8.1 36.86 36.41 • • 28.39 12.33 1.44 8.5 43.65 43.18 28.40 12.43 1.38 9.0 50.43 49.96 28.41 13.54 1.42 9.5 50.74 50.27 28.42 14.69 1.47 10.0 51.06 50.59 28.43 15.87 1.51 10.5 51.38 50.90 28.44 17.09 1.55 11.0 51.69 51.22 28.45 18.35 1.59 11.5 52.01 51.53 28.46 19.65 1.63 12.1 52.33 51.85 28.47 20.98 1.67 12.6 52.64 52.17 28.48 22.35 1.71 13.1 52.96 52.48 28.49 23.75 1.74 13.6 53.28 52.80 28.50 25.19 1.78 14.2 53.59 53.11 I Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese 8 Nichols Inc FlowMaster v6.1 [614o] 09/25/03 04:43:08 PM O Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 2 Woodlawn Street Flow Capacity 192 Ft South of Shadowbend Worksheet for Irregular Channel Project Description Worksheet Woodlawn xsect 192 south of st Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 001600 ft/ft Water Surface Elev. 28.50 ft Options • Current Roughness Methc wed Lotter's Method Open Channel Weighting I wed Lotter's Method Closed Channel Weightinc Horton's Method Results Mannings Coeffic 0.014 Elevation Range '.86 to 28.98 Discharge 25.19 cfs • Flow Area 14.2 ft2 Wetted Perimeter 53.59 ft Top Width 53.11 ft Actual Depth 0.64 ft Critical Elevation 28.42 ft Critical Slope 0.004796 ft/ft Velocity 1.78 ft/s Velocity Head 0.05 ft Specific Energy 28.55 ft Froude Number 0.61 Flow Type Subcritical Roughness Segments Start End Mannings Station Station Coefficient 0+00 0+15 0.035 0+15 0+56 0.013 0+56 0+68 0.035 Natural Channel Points Station Elevation (ft) (ft) 0+00 28.97 0+15 28.38 0+26 28.40 • 0+27 27.93 0+41 28.38 0+55 27.86 0+56 28.36 0+59 28.40 0+62 28.00 0+68 28.98 Project Engineer: Longview Office 9 9 c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 09/25/03 04:46:03 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Woodlawn Xsect 192 ft South of Shadowbend Rating Table for Irregular Channel Project Description Worksheet Woodlawn xsect 192 south of st Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 001600 ft/ft Options Current Roughness Methcwved Lotter's Method Open Channel Weighting Iwed Lotter's Method Closed Channel Weighting Horton's Method Attribute Minimum Maximum Increment Water Surface Elevat 27.93 28.50 0.01 Water Discharge Velocity Flow Wetted Top Surface (cfs) (ft/s) Area Perimeter Width Elevation (ftz) (ft) (ft) (ft) 27.93 0.03 0.48 0.1 1.98 1.95 27.94 0.04 0.49 0.1 2.61 2.57 27.95 0.06 0.51 0.1 3.23 3.18 27.96 0.08 0.54 0.2 3.85 3.79 27.97 0.11 0.57 0.2 4.47 4.40 • • 27.98 0.15 0.60 0.2 5.09 5.02 27.99 0.19 0.64 0.3 5.71 5.63 28.00 0.24 0.67 0.4 6.33 6.24 28.01 0.28 0.67 0.4 7.09 6.99 28.02 0.33 0.67 0.5 7.85 7.74 28.03 0.39 0.68 0.6 8.60 8.48 28.04 0.46 0.69 0.7 9.36 9.23 28.05 0.54 0.71 0.8 10.12 9.98 28.06 0.63 0.72 0.9 10.88 10.73 28.07 0.72 0.74 1.0 11.64 11.48 28.08 0.83 0.76 1.1 12.39 12.23 28.09 1.14 0.94 1.2 13.15 12.97 28.10 1.30 0.96 1.4 13.91 13.72 28.11 1.48 0.99 1.5 14.67 14.47 • 28.12 1.67 1.02 1.6 15.43 15.22 28.13 1.87 1.04 1.8 16.19 15.97 28.14 2.09 1.07 2.0 16.94 16.72 28.15 2.33 1.09 2.1 17.70 17.46 28.16 2.58 1.12 2.3 18.46 18.21 28.17 2.85 1.14 2.5 19.22 18.96 28.18 3.14 1.17 2.7 19.98 19.71 28.19 3.44 1.19 2.9 20.74 20.46 28.20 3.76 1.21 3.1 21.49 21.21 28.21 4.10 1.24 3.3 22.25 21.95 28.22 4.46 1.26 3.5 23.01 22.70 28.23 4.84 1.28 3.8 23.77 23.45 28.24 5.24 1.31 4.0 24.53 24.20 28.25 5.66 1.33 4.3 25.28 24.95 Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 09/25/03 04:43:08 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury, CT 06708 USA (203)755-1666 Page 1 of 2 Shadowbend Typical Section Surface Flow Capacity Rating Table for Irregular Channel • Project Description • ' • Worksheet Shadowbend xsi - Flow Element Irregular Channe • Method Manning's Form' • Solve For Discharge Input Data Slope 002000 ft/ft Options • •, Current Roughness Methc)ved Lotter's Method • • Open Channel Weighting bved Lotter's Method Closed Channel Weighting. Horton's Method i Attribute Minimum Maximum Increment • • Water Surface Elevat 28.00 28.93 0.01 • • Water Discharge Velocity Flow Wetted Top Surface (cfs) (ft/s) Area Perimeter Width • Elevation ( ) (It) (It) at) 28.00 0.58 0.90 0.6 8.65 8.55 28.01 0.69 0.94 0.7 9.23 9.12 • 28.02 0.81 0.98 0.8 9.81 9.69 28.03 0.94 1.02 0.9 10.38 10.26 ,. 28.04 1.09 1.06 1.0 10.96 10.83 - . 28.05 1.25 1.09 1.1 11.54 11.40 28.06 1.42 1.13 1.3 12.11 11.97 28.07 1.61 1.16 " . - 1.4 12.69 12.54 • 28.08 1.81 1.20 1.5 13.27 13.11 28.09 2.03 1.23 1.6 13.84 13.68 28.10 2.26 1.27 1.8 14.42 14.25 - 28.11 2.51 1.30 1.9 15.00 14.82 28.12 2.77 1.33 2.1 15.58 15.39 28.13 3.05 1.37 2.2 16.15 15.96 _ 28.14 3.35 1.40 2.4 16.73 16.53 28.15 3.67 1.43 2.6 17.31 17.10 28.16 4.01 1.46 2.7 17.8B 17.67 28.17 4.36 1.49 2-9 18.46 18.24 28.18 4.73 1.53 3.1 19.04 18.81 • 28.19 5.13 1.56 3.3 19.61 19.38 28.20 5.54 1.59 3.5 20.19 19.95 1 28.21 5.97 1.62 3.7 20.77 20.52 28.22 6.42 1.65 3.9 21.34 21.09 28.23 6.90 1.68 4.1 21.92 21.66 28.24 7.39 1.71 4.3 22.50 22.23 • 28.25 7.91 1.73 4.6 23.07 22.80 28.26 8.45 1.76 4.8 23.65 23.37 28.27 9.01 1.79 5.0 24.23 23.94 28.28 9.59 1.82 5.3 24.81 24.51 28.29 10.20 1.85 5.5 25.38 25.08 28.30 10.83 1.88, 5.8 25.96 25.65 28.31 11.48 1.90 6.0 26.54 26.22 28.32 12.16 1.93 6.3 27.11 26.79 Project Engineer:Longview Office ,stad\fmw\street drainage capacityfm2.fm2 Freese 8 Nichols Inc FlowMaster v6.1 [614o] 1 04:35:57 PM 0 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 3 • Shadowbend Typical Section Surface Flow Capacity Rating Table for Irregular Channel Water Discharge Velocity Flow Wetted Top Surface (cfs) (ft/s) Area Perimeter Width Elevation OP) (ft) • (ft) (ft) 28.33 12.86 1.96 6.6 27.69 27.36 28.34 13.59 1.99 6.8 28.27 27.93 28.35 14.34 2.01 7.1 28.84 28.50 28.36 14.56 1.96 7.4 29.36 29.01 28.37 14.82 1.92 7.7 29.87 29.53 28.38 15.11 1.89 8.0 30.38 30.04 28.39 15.43 1.86 8.3 30.90 30.55 28.40 15.77 1.83 8.6 31.41 31.06 28.41 16.14 1.81 8.9 31.92 31.58 28.42 16.53 1.79 9.2 32.44 32.09 • 28.43 16.93 1.77 9.6 32.95 32.60 28.44 17.36 1.75 9.9 33.46 33.12 28.45 17.80 1.74 10.2 33.98 33.63 28.46 18.26 1.73 10.6 34.49 34.14 28.47 18.74 1.72 10.6 35.00 34.65 28.48 19.24 1.71 11.3 35.52 35.17 28.49 19.75 1.70 11.6 36.03 35.68 28.50 20.27 1.69 12.0 36.54 36.19 28.51 20.81 1.69 12.3 37.06 36.71 28.52 21.37 " 1.68 12.7 37.57 37.22 28.53 21.94 1.68 13.1 38.08 37.73 28.54 22.53 1.67 13.5 38.59 38.24 28.55 23.13 1.67 13.9 39.11 38.76 28.56 23.74 1.67 14.2 39.62 39.27 28.57 24.37 1.67 14.6 40.13 39.78 28.58 25.01 1.66 15.0 40.65 40.29 28.59 25.67 1.66 15.4 41.16 40.81 28.60 26.34 1.66 15.9 41.67 41.32 28.61 27.03 1.66 16.3 42.19 41.83 28.62 27.73 1.66 16.7 42.70 42.35 28.63 28.44 1.66 17.1 43.21 42.86 28.64 29.17 1.66 17.5 43.73 43.37 28.65 29.92 1.66 18.0 44.24 43.88 28.66 30.67 1.66 18.4 44.75 44.40 28.67 31.44 1.67 18.9 45.27 44.91 28.68 32.23 1.67 19.3 45.78 45.42 28.69 33.03 1.67 19.8 46.29 45.94 28.70 33.84 1.67 20.2 46.81 46.45 28.71 34.67 1.67 20.7 47.32 46.96 28.72 35.52 1.68 21.2 47.83 47.47 28.73 36.37 1.68 21.7 48.35 47.99 28.74 37.25 1.68 22.1 48.86 48.50 28.75 46.38 2.05 22.6 49.47 49.11 28.76 47.75 2.07 23.1 50.09 49.73 28.77 49.15 2.08 23.6 50.70 50.34 28.78 50.58 2.10 24.1 51.31 50.95 28.79 52.03 2.11 24.6 51.93 51.57 28.80 53.51 2.13 25.2 52.54 52.18 28.81 55.02 2.14 25.7 53.16 52.80 28.82 56.55 2.16 26.2 53.77 53.41 28.83 58.12 2.17 26.8 54.38 54.02 28.84 59.71 2.19 27.3 55.00 54.64 Project Engineer:Longview Office I c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 09/25/03 04:35:57 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 3 Shadowbend Typical Section Surface Flow Capacity Rating Table for Irregular Channel Water Discharge Velocity Flow Wetted Top Surface (cfs) (ft/s) Area Perimeter Width • Elevation (ft2) (ft) (ft) (ft) 28.85 61.34 2.20 27.8 55.61 55.25 28.86 62.27 2.19 28.4 56.26 55.90 28.87 63.22 2.18 29.0 56.91 56.55 28.88 64.20 2.17 29.5 57.56 57.20 28.89 65.20 2.17 30.1 58.21 57.85 28.90 66.22 2.16 30.7 58.86 58.50 28.91 68.10 2.18 31.3 59.17 58.80 28.92 70.00 2.20 31.9 59.48 59.10 28.93 71.93 2.22 32.5 59.79 59.40 • • Project Engineer.Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 09/25/03 04:35:57 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 3 of 3 Woodlawn Street xsect 2 Cross Section for Irregular Channel Project Description Worksheet Woodlawn xse, Flow Element Irregular Chant Method Manning's Forr • Solve For Discharge Section Data Mannings Coefficier 0.017 Slope 0.001600 tuft Water Surface Elev; 28.90 ft Elevation Range 3.16 to 28.97 Discharge 22.86 cfs • 29.00p 1 28.10 0+00 0+05 0+10 0+15 0+20 0+25 0+30 0+35 0+40 0+.45 0+50 0+55 0+60 V:4.0 H:1 NTS ' 1 • • • • Project Engineer:Longview Office c:\haestadVmw\street drainage capacityfm2.fm2 Freese ilk Nichols Inc FlowMaster v6.1 [614o] 08/27/03 09:01:26 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 O O m 0 mc'CC * 0 O 0 0 N 5 o g - -o J 0 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N < = 0 n) O g 'O ( V a M a 0 O• aO 92. 00 co co 07 0o O 03 CO CO CO CO CO 00 0o OD po O CO O CO CO CO 03 CO CO CO 0l CO CO CO OD co co O: S N W m 'CO V V V V V m a) On ao) m in (n in N w }a A A A .A W fJ CO W (.) N IV N N N --. -. o'a W N O O N O O x Q o, O CO O) A N O Co O A O CO CO A N O 03 O A N O CO 0) A N O co a) A N O CO O) j a v - !n = a 0 T W D3 OT a - N O co O 011 7. x m co O * _ _ N A n O)' C C O 3 CD n J s. 'No 6 W N (O ° v O P U) A W W N N O O O O O O O O o 0 0 0 o 'o) tAJI 5'0.1 (D S 0) 9 O V L.) -+ CO CO CO (0 (D A. V V N O (.11 IV co V U1 ,.o. N N L. O op O O O a fD . (a m > 0 W (0 A O O U) W co co co (O N O Ul al O O A W cn O N O -, co N W N W A D co F�r C ( N j Eli N N = a O _ C © 2 O O O o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 q n _ f O S N 01 N a (a N N IV • L' O O (a <o 'co 'co Oo V V a) b in U) U) A A co la) W (a) IJ IJ N iv -. O Z ? '^ - n n 7 )o a y n! (O Ul V W (0 Ul co co (D cn V N CO A (0 Ul V W (0 m A -, 00 On co o O N CO D 0) 3 < < S 7 C G ((n•, m c a s (- C IA I m m N al D"() 3 0 I- l- 0 0 n 7 O N 'S a a y N 0 3 n O (o (o CO V V a) a) U) rn A A co co N N N -. -. -. 0 0 0 0 0 0 0 0 0 0 ? `'0 f ao ° a a ,� 7 (p V CO N in 0o N O) O in b A O U) V (a) O V A N O 0) Q) in A fa) N - - -' N la) D co X o 0 o O. N '2 _ O. (�D l�D (�D y 2 W W W W W W N N N N N N N N 3 ID 3 j- T T 0 N O) V col A N O co CO v O A W -" O (D V O) A CO -+ O CO .1 O A A CO N N O al T1 O m N O in (O (a) ()) V W Oo A 'co (N O V (o m A (0 U) O lA (p co V -� (n ? ...N o O C. a s Iv O P A Ul V co O -• co O A O Ul -s a) N 0o co (0 A O a) --. V N co A on co O N A O co A a N n 0 C. in CO NI VD E.a N La.) La) CO C.) CO Cc)CO N N N N N N 07 00 a) U) CO N O f0 Oo V d) A W O co �1 a) A W --, O CO V a) A W W N N O O. �„ 2 in co fa) :-.IO N co )0) O co A. O in V (a) 03 A O in -+ V co 0) .o�a., O (Ul1 CO A CO N - U(�I . o� w o O N A coOo O O U) (0 a) O A -• CO00 N co a) co O V co(o to co A so > C/7 PC ... a ID (> t fD 0 1 �+ ID pri 9 CO a 2 C 0IC 0 if n• S V 3 0 co D . U Z N 0 W V or ', o CD `N 0) O 0) m m -n b o f m K N o il 0 a ) 0)rc CFr•• Co f • a) O o, A3 N Si a) Woodlawn Street Surface Flow Capacity Rating Table for Irregular Channel Water Discharge Velocity Flow Wetted Top Surface (cfs) (ft/s) Area Perimeter Width Elevation (ft2) (ft) (ft) (ft) 28.82 15.34 1.34 11.5 42.81 42.47 28.84 17.05 1.38 12.4 46.79 46.45 • 28.86 18.86 1.41 13.3 50.36 50.02 28.88 20.80 1.45 14.4 53.54 53.20 28.90 22.86 1.48 15.5 58.34 58.00 • I • 1 • • • • • • Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614oj 08/27/03 09:02:06 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 2 CHART A Discharge(cfs)@ Sta 0+54 • Coward Creek Tributary Capacity vs.Water Surface Elevation -Discharge(cfs)@ Sta 1+50 30.0 -Discharge(cfs)@ Sta 4+75 � .... a.a..�.. '.. . . \ *.! * i Q \ � a r. Yy � .■ a at eF�cr ' : z , L"w" 1 \\tey\a`\""\ >\ \ s \a\\ \ Discharge(cfs)@ Sta 7+12k\aa � r \ a 2�\., al.a. I ati \ * 4�`a \\\-* ` R 0 , � \ \�29.0 *\� *0 h \l* \\\�\ e**Z 4t\\\ �t* .� \ a� \ * ** .7 w� a' af i r s Finished Floor Elevation 29.33 @ Sta 1+50iFih � v" • 1y y �v ' *«' mo2g0 i Zi\ Typcams \ y , \ 0AtI. • 27 0 Floor Elevation �� 4*,� 7• Finished'Floor Elevation 25.44 @ Sta 4+75 is\\ � ��,.� a i 744 `�-*a `ae .i i 1'' *** 4e\ * .r\ $\ i ** a \s * *.a. 4a ** „,*•, a<\ �a,,—Ayo^',a. � �y \414S . �4 ` d q . VA4L. \ \ \ 26.0 ay\\\ "r1C A a a\ „-a'_.v'\ '? `� <\\\as\ \\\\tee a ez\\ \'' \ ' ' `\a \-, *,', m\ " *4� �4 ,�sy< - vW ,* wv, 4y y v. **r * � 1 �� � Y: Finished Floor Elevation 22.30 @ Sta 7+12 �� Total Exist Flow uyRv ., 25 0 k to Tributary 1 * i* a* � •�a 2 a'4-7 r ; yh€ % asx*t14, a s 4 e i'� 'b\�''',a+ ;O < a \ 4 i c rea o �. 40 .� £Q5=239cfs n ▪'i , , \\.�..�- e \ \s P, i5 v. 240 ° Q100=465 cfs < � ' \ €ti\\ . � �4 �\` �ft�N , o \ 3 .� � �.. t4� 4 ate�o� aa �\ »��**\ � \���\ . ��.�\�c ! \\ �\y�: * \ \ \\�*\ �? a . , \\**- 4 �m ,�� \*a*� \ hh \ *\ —W a . \* .� .a,t,\ \a \ ao � .?y y Y, e \4 \\ V * %it3 \''' .aa�1 \ \a *\ \ . \ . w � wt x-w '� + k- vet ar sue° w ei' , "' t!, ."0 • : w taw \ � a z r• V's ,�' \ � \ ***744* a \\ r.\� * . ay ,.\ a \ acc e � \. a\to e a21.0 � a K b. . r�a r `�V �\ a *. a. <^ . .er a �**" .4` ti�i .* * * r=. a *\ ? \� ate \ *�a ,�**\ . h\ `ya ;o \e\� �\ * ram - �. � ' . \I�a �* .\ \..a,.\��� > 4., �at. �� *„ \\ Mn 3 �� y� \*4 :* \ \ \ �\ a\* .. , .�..� \ `,v , . \,\ o\ � ` a\ at.4�a . �� ti * **a a \V . " a `� *1 3 a < **�C k � a � � rn� `� aa` �:�., g \ a 1 18.0 '.2e i va i\ g\» itat1 .,\ � ,x 1 a .: Vie\ . \ e :\ \ a a �y190 �� *Z\ . *\* a*\\ e\ \*a. *\ r�y� S :* �� � :N I .i? a\� , 44� �3:. . Z * <a &* 1 1� , . � �t\ ` . 1 x t a TotalDeveloped Flow'7 - • 4 a�4a * s \ 4 .* -4 \ � * 4\e'• \ - ''' '"� . \ '°'. \ ' \�\ . \� '' �. -� $7 *\ ?�*�to Tributary 11141,111 �� ��*\ a \,V'�\ *., -a.a�� .�q\ �� �a �. a�, �. \_' , �a\ . \\�\\\u\ \\ � -\*: , 7� �\, � "c ll . � _- s a aN' \ \ Q5=252 cfs e � ,'7, *170 \ s \ t �8 \\* �2 . {� * \� ' a \* * *f ** ^ a*ay * . - \ Q100=490 cfs 0 • 4444 a %\",w , � 3 � ` ,, �0,0„00 \ w a \ < \\.16 0i � \' a r \\ �\ i .Z«1`a , o? � � •am at� , * i ti ^ ti5 ti5 ,;\ per bp` 4, \\\ \pb ,bh 40 r^b ,,,ycb t.cla txcp hy'") 05) 0 434) ^p'ZIa $ ebb o(ti �o\ ,^ti hhh ^k^) c45 ,y1) ti, ti, ti� ti, ti, ti, ti, Discharge(cfs) Woodlawn Xsect 192 ft south of Shadowbend Cross Section for Irregular Channel Project Description Worksheet Woodlawn xsect 192 south of st Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficier 0.014 Slope 0.001600 ft/ft Water Surface Elev; 28.32 ft. Elevation Range '.86 to 28.98 Discharge 9.19 cfs • 29.0 28.40 — ... 27.80 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 • V:4.0\ H:1 NTS • Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 10/02/03 02:19:17 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Tributary of Coward's Creek @ Station 0+54 Worksheet for Irregular Channel Project Description Worksheet Friendswood Coward Ck Tributary Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 010400 ft/ft Water Surface Elev. 24.60 ft Options Current Roughness Methc wed Lotter's Method Open Channel Weighting Wed Lotter's Method Closed Channel Weightint Horton's Method Results . Mannings Coeffic 0.041 • Elevation Range 1.47 to 26.57 Discharge 492.64 cfs Flow Area 71.1 ft2 Wetted Perimetei 27.44 ft Top Width 25.07 ft • Actual Depth 5:13 ft Critical Elevation 23.94 ft • Critical Slope 0.020633 ft/ft • Velocity 6.93 ft/s Velocity Head 0.75 ft Specific Energy 25.35 ft Froude Number 0.73 I Flow Type Subcritical Roughness Segments' Start End Mannings • Station Station Coefficient 0+52 0+43 0.045 • 0+43 0+38 0.050 0+38 0+34 - 0.035 i 0+34 0+32 • 0.050 0+32 0+20 0.035 • - 0+20 0+00 0.060 Natural Channel Points Station Elevation (ft) (ft) 0+52 26.37 0+43 22.09 0+38 21.18 0+34 19.47 0+32 19.52 0+20 26.45 0+00 26.57 Title: Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [61 4oj 08/07/03 12:52:55 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 2 Cross Section Cross Section for Irregular Channel Project Description Worksheet Friendswood Coward Ck Tributary Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficiei 0.041 Slope 0.010400 ft/ft Water Surface Elev 24.60 ft Elevation Range 1.47 to 26.57 Discharge 492.64 cfs 27.00 C - 26.00 • 25.00 24.00'..._... ._ ..: 23.00 22.00 21.00 (- • 20.00 19.00... . ..._.. °_. ..._ .. .._. .. _.. ._-. . __...._ 0+00 0+05 0+10 0+15 0+20 0+25 0+30 0+35 0+40 0+45 0+50 0+55 V:3.03030303\ H:1 NTS • Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestad\fmw\friendswood channel 054.fm2. Freese&Nichols Inc FlowMaster v6.1 [61.4o] 08/07/03 12:39:17 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 0670E USA (203)755-1666 Page 1 of 1 - I Tributary of Coward's Creek @ 1+50 Worksheet for Irregular Channel 'Project Description Worksheet Friendswood coward Ck Tributary - Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 005600 ft/ft Water Surface Elev. 24.30 ft Options Current Roughness Methoved Lotter's Method Open Channel Weighting wed Lotter's Method Closed Channel Weighting Horton's Method Results Mannings Coeffic 0.046 Elevation Range 1.94 to 26.20 Discharge 492.21 cfs Flow Area 101.2 ft2 Wetted Perimetei 35.25 ft Top Width 33.16 ft Actual Depth 5.36 ft Critical Elevation 22.70 ft Critical Slope 0.025348 ft/ft Velocity 4.86 ft/s Velocity Head 0.37 ft Specific Energy 24.67 ft Froude Number 0.49 Flow Type Subcritical Roughness Segments Start End Mannings Station Station Coefficient 0+00 0+18 0.045 0+18 0+30 0.050 0+30 0+34 0.045 0+34 0+39 0.050 0+39 0+54 0.045 Natural Channel Points Station Elevation (ft) (ft) 0+00 25.80 0+18 24.14 0+30 19.27 0+34 18.94 0+39 19.44 0+43 21.63 0+54 26.20 Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 12:52:29 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury, CT 06708 USA (203)755-1666 Page 1 of 1 Cross Section Cross Section for Irregular Channel Project Description Worksheet Friendswood coward Ck Tributary - Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficiei 0.046 Slope 0.005600 ftift Water Surface Elev. 24.30 ft Elevation Range 1.94 to 26.20 Discharge 492.21 cfs i 27.00.. . .... .. .. .... 26.00r. -. __ 25.00 24.00;.__ ;. . . .. . 23.00 ;. . . ' 22.00,. 21.00 20.00 ... 19.00 18.00. . 0+00 0+05 0+10 0+15 0+20 0+25 0+30 0+35 0+40 0+45 0+50 0+55 V:3.03030303\ H:1 NTS Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestadlfmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 12:49:09 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 • Tribuary of Coward's Creek @ Station 4+75 Worksheet for Irregular Channel Project Description Worksheet Friendswood Coward Ck Tributary Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 009500 ft/ft Water Surface Elev. 21.55 ft Options Current Roughness Methoved Lotter's Method Open Channel Weighting wed Lotter's Method Closed Channel Weighting Horton's Method Results Mannings Coeffic 0.050 Elevation Range i.48 to 25.05 Discharge 492.26 cfs Flow Area 93.5 ft2 Wetted Perimeter 38.48 ft Top Width 35.79 ft Actual Depth 6.07 ft Critical Elevation 20.23 ft Critical Slope 0.030488 ft/ft Velocity 5.27 ft/s Velocity Head 0.43 ft Specific Energy 21.98 ft Froude Number 0.57 Flow Type Subcritical • Roughness Segments Start End Mannings Station Station Coefficient • 0+00 0+15 0.045 � - 0+15 0+39 0.060 0+39 0+45 0.050 0+45 0+63 0.045 0+63 0+75 0.050 0+75 0+97 0.060 Natural Channel Points Station Elevation (ft) (ft) 0+00 25.05 0+15 23.25 0+39 22.72 0+45 22.00 0+49 20.73 0+55 19.66 0+63 15.48 0+65 15.53 • Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 12:55:11 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 2 Cross Section Cross Section for Irregular Channel Project Description Worksheet Friendswood Coward Ck Tributary Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficiei 0.050 Slope 0.009500 ft/ft Water Surface Elev. 21.55 ft Elevation Range i.48 to 25.05 Discharge 492.26 cfs i 26.00 25.00 24.00'.. 23.00 21.00 .. . . .. ._.. 20.00 . 19.00 .. _ . _ ._.. .. 18.0017.00 -. . .. . .._ :_ 16.00 15.00. ..... 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 V:3.0\ H:1 NTS Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 12:54:57 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Tribuary of Coward's Creek @ Station 4+75 Worksheet for Irregular Channel Natural Channel Points Station Elevation (ft) (ft) 0+67 15.74 0+71 18.72 0+75 20.52 0+97 23.72 Notes:Sta 0+54 • • Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Sla-ton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 12:55:11 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 2 Tributary of Coward's Creek @ Station 7+12 Worksheet for Irregular Channel Project Description Worksheet Friendswood Coward Ck Tributary Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Slope 024800 ft/ft Water Surface Elev. 18.04 ft Options Current Roughness Methoved Lotter's Method Open Channel Weighting wed Lotter's Method Closed Channel Weightint Horton's Method • • Results Mannings Coeffic 0.046 Elevation Range 1.80 to 22.30 Discharge 493.66 cfs Flow Area 57.8 ft2 Wetted Perimeter 26.46 ft Top Width 24.49 ft Actual Depth 4.24 ft Critical Elevation 18.00 ft Critical Slope 0.025952 ft/ft Velocity 8.53 ft/s Velocity Head 1.13 ft Specific Energy 19.17 ft Froude Number 0.98 Flow Type Subcritical Roughness Segments • Start End Mannings Station Station Coefficient 0+00 0+10 0.045 0+10 0+22 0.060 0+22 0+29 0.050 0+29 1+05 0.045 Natural Channel Points Station Elevation (ft) (ft) 0+00 22.30 0+10 20.45 0+22 16.15 • 0+29 15.30 0+31 14.30 0+34 13.80 0+36 14.17 0+42 18.62 0+65 19.75 1+05 21.86 Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Slaton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [61 4o] 08/07/03 12:57:17 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 2 Cross Section Cross Section for Irregular Channel Project Description Worksheet Friendswood Coward Ck Tributary Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings Coefficiei 0.046 Slope 0.024800 ft/ft Water Surface Elev. 18.04 ft Elevation Range 1.80 to 22.30 Discharge 493.66 cfs I 23.00 ._. 19.00 :. 17.00. 15.00 13.00 ...__ .. . • 0+00 0+20 0+40 0+60 0+80 1+00 1+20 V:3.03030303\ H:1 NTS Title:Friendswood Coward Creek Tributary Analysis Project Engineer:Rodney Sla ton c:\haestad\fmw\friendswood channel 054.fm2 Freese&Nichols Inc FlowMaster v6.1 [61 4o] 08/07/03 12:56:29 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Table Rating Table for Rectangular Channel Project Description Worksheet Woodlawn RCB ci Flow Element Rectangular Chan Method Manning's Formul; Solve For Discharge Input Data Mannings Coeffic 0.013 Slope 000900 Nit Attribute Minimum Maximum Increment Depth(ft) 4.00 5.00 1.00 Bottom Width(ft) 7.00 9.00 1.00 Depth Bottom Discharge Velocity Flow Wetted Top (ft) Width (cfs) (ft/s) Area Perimeter Width (ft) (I2) (It) (It) 4.00 7.00 145.56 5.20 28.0 15.00 7.00 5.00 7.00 194.23 5.55 35.0 17.00 7.00 4.00 8.00 174.18 5.44 32.0 16.00 8.00 5.00 8.00 233.57 5.84 40.0 18.00 8.00 4.00 9.00 203.57 5.65 36.0 17.00 9.00 5.00 9.00 274.17 6.09 45.0 19.00 9.00 • • • • Project Engineer.Longview Office c:\...\fmw\friendswood existing woodlawn sd.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 11:51:22 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Woodlawn Drive Roadway Drainage Capacity • Worksheet for Irregular Channel Project Description Worksheet Woodlawn xse' Flow Element Irregular Chant Method Manning's Forr Solve For Discharge Input Data Slope 001600 ft/ft Water Surface Elev; 28.14 ft Options Current Roughness Methc)ved Lotter's Method Open Channel Weighting[wed Lotter's Method Closed Channel Weighting. Horton's Method Results Mannings Coeffic 0.018 Elevation Range 3.62 to 28.97 Discharge 116.41 cfs Flow Area 53,0 ft2 Wetted Perimeter 97.76 ft Top Width 97.34 ft Actual Depth 1.52 ft Critical Elevation 27.89 ft Critical Slope 0.006353 ft/ft Velocity 2.20 it/s Velocity Head 0.07 ft Specific Energy 28.21 ft Froude Number 0.52 Flow Type Subcritical Roughness Segments j Start End Mannings Station Station Coefficient 0+00 0t04 0.013 0+04 0+38 0.035 0+38 0+68 0.013 0+68 1+30 0.035 Natural Channel Points Station Elevation (ft) (ft) 0+00 28.97 0+04 28.95 0+25 27.02 0+30 26.62 0+35 27.19 0+38 27.50 0+39 27.16 0+53 27.65 0+67 27.26 0+68 27.72 Project Engineer:Longview Office c:thaestadVmwtstreet drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o[ 08/07/03 03:35:43 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 bf 2 Woodlawn Drive Roadway Drainage Capacity Worksheet for Irregular Channel Natural Channel Points Station Elevation (ft) (ft) 0+80 27.83 0+90 27.88 1+01 28.02 1+30 28.40 • Project Engineer:Longview Office c:\haestad\fmw\street drainage capacityfm2.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o] 08/07/03 03:35:43 PM 0 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 2 Culvert Designer/Analyzer Report Friendswood Coward Creek Analysis Component Storm Event Design Discharge 252.00 cfs Peak Discharge Method:User-Specified Design Discharge 252.00 cfs Check Discharge 490.00 cfs Taiiwater properties:Irregular Channel Roughness Segments Start End Mannings Station Station Coefficient 0+00 0+22 0.045 0+22 0+31 0.050 0+31 0+34 0.045 0+34 0+36 0.050 0+36 0+42 0.045 0+42 1+05 0.050 Natural Channel Points • Station Elevation (ft) (ft) 0+00 22.30 0+10 20.45 0+22 16.15 0+29 15.30 • 0+31 14.30 0+34 13.80 0+36 14.17 0+42 18.62 0+65 19.75 1+05 21.86 Tailwater conditions for Design Storm. • Discharge 252.00 cfs Actual Depth 3.30 ft Velocity 6.88 ft/s I Name Description Discharge HW Elev. Velocity Culvert-1 2-48 inch Circular 252.01 cfs 20.12 ft 11.16 ft/s Weir Roadway 0.00 cfs 20.12 ft N/A Total ------ 252.01 cfs 20.12 ft N/A Project Engineer:Freese&Nichols Inc c:\...\cvmVriendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/05/03 09:16:35 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 1 o f 3 Culvert Designer/Analyzer Report Friendswood Coward Creek Component:Culvert-1 Culvert Summary Computed Headwater Elevz 20.12 ft Discharge 252.01 cfs Inlet Control HW Elev. 20.12 ft Tailwater Elevation 17.10 ft Outlet Control HW Elev. 20.03 ft Control Type Inlet Control Headwater Depth/Height 1.49 • Grades Upstream Invert 14.18 ft Downstream Invert 14.12 ft Length 43.00 ft Constructed Slope 0.001395 ft/ft • Hydraulic Profile Profile M2 Depth,Downstream 3.37 ft Slope Type Mild Normal Depth N/A ft Flow Regime Subcritical Critical Depth 3.37 ft Velocity Downstream 11.16 ft/s Critical Slope 0.007353 ft/ft Section I Section Shape Circular Mannings Coefficient 0.013 Section Material Concrete Span 4.00 ft Section Size 48 inch Rise 4.00 ft ' Number Sections 2 Outlet Control Properties Outlet Control HW Elev. 20.03 ft Upstream Velocity Head 1.57 ft Ke 0.20 Entrance Loss 0.31 ft Inlet Control Properties Inlet Control HW Elev. 20.12 ft Flow Control Submerged Inlet Type Groove end projecting Area Full 25.1 ftz • K 0.00450 HDS 5 Chart 1 M 2.00000 HDS 5 Scale 3 C 0.03170 Equation Form 1 Y 0.69000 • Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/05/03 09:16:35 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 2 of 3 • Culvert Designer/Analyzer Report Friendswood Coward Creek Component:Weir Hydraulic Component(s):Roadway Discharge 0.00 cfs Allowable HW Elevation 20.12 It Roadway Width 12.00 ft Overtopping Coefficient 2.90 US Low Point 21.04 ft Headwater Elevation NIA ft • Discharge Coefficient(Cr) 2.90 Submergence Factor(Kt) 1.00 Tailwater Elevation 17.10 ft Sta(ft) Elev.(ft) 0.00 22.25 28.00 21.15 38.00 21.04 55.00 21.88 • 1 Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/05/03 09:16:35 AM 0 Haestad Methods,Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 3 of 3 Culvert Designer/Analyzer Report Friendswood Coward Creek • Analysis Component Storm Event Check Discharge 490.00 cfs Peak Discharge Method:User-Specified Design Discharge 252.00 cfs Check Discharge 490.00 cfs Tailwater properties:Irregular Channel • Roughness Segments Start End Mannings Station Station Coefficient 0+00 0+22 0.045 • 0+22 0+31 0.050 0+31 0+34 0.045 • 0+34 0+36 0.050 • 0+36 0+42 0.045 • 0+42 1+05 0.050 • Natural Channel Points Station Elevation . (ft) [ft) 0+00 22.30 0+10 20.45 0+22 16.15 0+29 15.30 0+31 14.30 0+34 13.80 0+36 14.17 0+42 18.62 0+65 19.75 1+05 21.86 Tailwater conditions for Check Storm. Discharge 490.00 cfs Actual Depth 4.21 ft Velocity 8.59 ft/s Name Description Discharge HW Elev. Velocity Culvert-1 2-48 inch Circular 331.92 cfs 22.47 ft 13.31 ft/s Weir Roadway 157.94 cfs 22.47 ft N/A Total --- 489.86 cfs 22.47 ft N/A it Project Engineer:Freese&Nichols Inc c:\...\cvm\riendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/05/03 09:28:31 AM 0 Flaestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 1 of 3 Culvert Designer/Analyzer Report Friendswood Coward Creek Component:Culvert-1 Culvert Summary Computed Headwater Eleve 22.47 ft Discharge 331.92 cfs Inlet Control HW Elev. 22.47 ft Tailwater Elevation 18.01 ft Outlet Control HW Elev. 21.87 ft Control Type Inlet Control Headwater Depth/Height 2.07 Grades Upstream Invert 14.18 ft Downstream Invert 14.12 ft Length 43.00 ft Constructed Slope 0.001395 ft/ft Hydraulic Profile Profile CompositeM2PressureProfile Depth,Downstream 3.89 ft Slope Type Mild Normal Depth N/A ft Flow Regime Subcritical Critical Depth 3.70 ft Velocity Downstream 13.31 ft/s Critical Slope 0.011561 ft/ft • Section Section Shape Circular Mannings Coefficient 0.013 Section Material Concrete Span 4.00 ft Section Size 48 inch Rise 4.00 ft Number Sections 2 Outlet Control Properties Outlet Control HW Elev. 21.87 ft Upstream Velocity Head 2.71 ft Ke 0.20 Entrance Loss 0.54 ft I ' _ Inlet Control Properties Inlet Control HW Elev. 22.47 ft Flow Control Submerged Inlet Type Groove end projecting Area Full 25.1 ft2 K 0.00450 HDS 5 Chart 1 M 2.00000 HDS 5 Scale 3 C 0.03170 Equation Form 1 Y 0.69000 Project Engineer:Freese&Nichols I nc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a1 08/05/03 09:28:31 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 2 of 3 Culvert Designer/Analyzer Report Friendswood Coward Creek Component:Weir Hydraulic Component(s):Roadway • Discharge 157.94 cfs Allowable HW Elevation 22.47 ft Roadway Width 12.00 ft Overtopping Coefficient 3.04 US Low Point 21.04 ft Headwater Elevation 22.47 ft Discharge Coefficient(Cr) 3.04 Submergence Factor(Kt) 1.00 Tailwater Elevation 18.01 ft Sta(ft) Elev.(It) 0.00 22.25 28.00 21.15 38.00 21.04 55.00 21.88 • • -- I -- I I • • Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMasterv2.0[2005a] 08/05/03 09:28:31 AM ©Haestad Methods,Inc. 37 Brookside Road Waterbury',CT 06708 USA +1-203-755-1666 Page 3 of 3 Culvert Analysis Report • Culvert-1 Culvert Summary Computed Headwater Elevr 18.53 ft Discharge 252.05 cfs Inlet Control HW Elev. 18.42 ft Taiiwater Elevation 17.10 ft Outlet Control HW Elev. 18.53 ft Control Type Outlet Control Headwater Depth/Height 1.09 • Grades Upstream Invert 14.18 ft Downstream Invert 14.12 ft Length 43.00 ft Constructed Slope 0.001395 ft/ft • • Hydraulic Profile Profile M2 Depth,Downstream 2.98 ft Slope Type Mild Normal Depth N/A ft Flow Regime Subcritical Critical Depth 2.78 ft Velocity Downstream 8.38 ft/s Critical Slope 0.004982 ft/ft Section Section Shape Circular Mannings Coefficient 0.013 Section Material Concrete Span 4.00 ft Section Size 48 inch Rise 4.00 ft Number Sections 3 Outlet Control Properties Outlet Control HW Elev. 18.53 ft Upstream Velocity Head 0.91 ft Ke 0.20 Entrance Loss 0.18 ft • • Inlet Control Properties Inlet Control HW Elev. - 18.42 ft Flow Control Unsubmerged Inlet Type Groove end projecting Area Full 37.7 ft2 K 0.00450 HDS 5 Chart 1 M 2.00000 HDS 5 Scale 3 C 0.03170 Equation Form 1 Y 0.69000 i Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/04/03 04:39:35 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 1 of 1 Rating Table Report Culvert-I Range Data: Minimum Maximum Increment Discharge 0.00 500.00 50.00 cfs Discharge(cf;)-IW Elev.(ft)TIN Elev.(ft) 0.00 14.18 13.80 50.00 15.94 15.56 100.00 16.74 16.18 150.00 17.37 16.53 200.00 17.95 16.83 250.00 18.51 17.09 300.00 19.07 17.25 350.00 19.67 17.47 400.00 20.51 17.68 450.00 21.45 17.86 500.00 22.51 18.04 • • • Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/04/03 04:41:33 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 1 of 1 Culvert Designer/Analyzer Report Friendswood Coward Creek Analysis Component Storm Event Check Discharge 490.00 cfs Peak Discharge Method:User-Specified Design Discharge 252.00 cfs Check Discharge 490.00 cfs Tailwater properties:Irregular Channel Roughness Segments Start End Mannings Station Station Coefficient 0+00 0+22 0.045 0+22 0+31 0.050 0+31 0+34 0.045 0+34 0+36 0.050 0+36 0+42 0.045 0+42 1+05 0.050 Natural Channel Points Station Elevation (ft) (ft) 0+00 22.30 0+10 20.45 0+22 16.15 0+29 15.30 0+31 14.30 ' 0+34 13.80 0+36 14.17 0+42 18.62 0+65 19.75 1+05 21.86 Tailwater conditions for Check Storm. Discharge 490.00 cfs Actual Depth 4.21 ft Velocity 8.59 f/s Name Description Discharge HW Elev. Velocity Culvert-1 3-48 inch Circular 462.14 cfs 21.70 ft 12.36 ft/s Weir Roadway 27.81 cfs 21.70 ft N/A Total --- 489.95 cfs 21.70 ft N/A •• Project Engineer:Freese&Nichols Inc • c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/04/03 04:43:42 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 3 Culvert Designer/Analyzer Report Friendswood Coward Creek Component:Culvert-1 Culvert Summary Computed Headwater Elev: 21.70 ft Discharge 462.14 cfs Inlet Control HW Elev. 21.70 ft Tailwater Elevation 18.01 ft Outlet Control HW Elev. 21.33 ft Control Type Inlet Control Headwater Depth/Height 1.88 Grades Upstream Invert 14.18 ft Downstream Invert 14.12 ft • Length 43.00 ft Constructed Slope 0.001395 ft/ft Hydraulic Profile Profile CompositeM2PressureProfile Depth,Downstream 3.89 ft Slope Type Mild Normal Depth N/A ft Flow Regime Subcritical Critical Depth 3.63 ft Velocity Downstream 12.36 ft/s Critical Slope 0.010070 ft/ft Section Section Shape Circular Mannings Coefficient 0.013 Section Material Concrete Span 4.00 ft Section Size 48 inch Rise 4.00 ft Number Sections 3 Outlet Control Properties Outlet Control HW Elev. 21.33 ft Upstream Velocity Head 2.34 ft Ke 0.20 Entrance Loss 0.47 ft • I Inlet Control Properties Inlet Control HW Elev. 21.70 ft Flow Control Submerged Inlet Type Groove end projecting Area Full 37.7 ft2 K 0.00450 HDS 5 Chart 1 M 2.00000 HDS 5 Scale 3 C 0.03170 Equation Form 1 Y 0.69000 • Project Engineer:Freese&Nichols Inc c:\_..\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/04/03 04:43:42 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 2 of 3 Culvert Designer/Analyzer Report Friendswood Coward Creek Component:Weir Hydraulic Component(s):Roadway Discharge 27.81 cfs Allowable HW Elevation 21.70 ft Roadway Width 12.00 ft Overtopping Coefficient 2.99 US Low Point 21.04 ft Headwater Elevation 21.70 ft Discharge Coefficient(Cr) 2.99 Submergence Factor(Kt) 1.00 Tailwater Elevation 18.01 ft Ste(ft) Elev.(ft) 0.00 ' 22.25 28.00 21.15 • 38.00 21.04 55.00 21.88 • ' I ,I • • ; • • Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08104/03 04:43:42 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 3 of 3 Performance Curves Report Friendswood Coward Creek Range Data: • Minimum Maximum Increment . Discharge 0.00 1,000.00 100.00 cfs • Performance Curves 24.0 - —.L HW Elev. ' I --• TW Elev. I I I I I I I 23.0 -4 i /- F I I I 1 I I I 1 22.0 1 4 -I- I I 1 I I I 1 I 1 21.0- J J L L J 1 L 20.0- 19.0 18.0- I r � I 17.0 1 I I I I I I I 1 16.0---- I I 1 I I I I I 1 15.0-- I I I I I I I I 14.0 4 L L A 4 ` I I I I I 1 13.0 I ' 0.0 200.0 400.0 600.0 800.0 1000.0 Discharge (cfs) Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/04/03 04:53:24 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 1 of 1 Performance Curves Report Culvert-I j Range Data: . Minimum Maximum Increment i ; Discharge 0.00 500.00 50.00 cfs , Performance Curves 23.0 , ; J. HW Elev. I 1 --f-- TW Elev. 22.0 , 1 s . ` i I I 1 1 1 I I I I 21.0 -I 4 4 -I. I- I I 1 1 I I I I I I 20.0- , 1 T -1 1 I 1 1 I I i1 19.0- -1 J i_ `-- 1 I I I I I I I F 18.0- , 4- r v I I 1 1 I I 1 I ,I • I I 1 17.0 J J 1 L J J I I 1 I I 1 I I I 1 I I I I I 16.0 1 T T r f 1 1 1 I I • I I I I I I 1 I 15.0--- J J 1 1 - J J I 1 1 1 I 1 k I I 14.0 ;1 I 1 I 1 1 I 1 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 450.0 500.0 Discharge (cfs) • ; I Project Engineer:Freese&Nichols Inc c:\...\cvm\friendswood coward ck 48 culvert.cvm FREESE AND NICHOLS,INC. CulvertMaster v2.0[2005a] 08/04/03 04:42:31 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA +1-203-755-1666 Page 1 of 1 Shadowbend 30" Storm Sewer Pressure Flow Capacity Rating Table for Pressure Pipe Project Description • • Worksheet Shadowbend 30"pressure flow Flow Element Pressure Pipe Method Hazen-Williams Formula Solve For Discharge Input Data Pressure at• 1.05 psi Pressure at: 0.00 psi Elevation at 23.57 ft Elevation at 22.85 ft C Coefficient 150.0 Diameter 30 in Attribute Minimum Maximum Increment Length(it) 0.00 355.00 50.00 Length Discharge (It) (cfs) 0.00 N/A 50.00 161.97 100.00 111.39 150.00 89.49 200.00 76.61 250.00 67.92 300.00 61.55 350.00 56.63 • • Project Engineer:Longview Office c:\...\fmw\iriendswood existing woodlawn sd.fm2 Freese&Nichols Inc FlowMaster v6.1 [6140] 08/28/03 12:44:11 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Shadowbend 30" Storm Sewer Pressure Flow Capacity • Worksheet for Pressure Pipe Project Description Worksheet Shadowbend 30"pressure flour Flow Element Pressure Pipe Method Hazen-Williams Formula Solve For Discharge Input Data. Pressure at• 1.05 psi Pressure at: 0.00 psi Elevation at 23.57 ft Elevation at 22.85 ft Length 155.00 ft • C Coefficient 150.0 Diameter 30 in Results Discharge 56.20 cfs Headless 3.14 ft Energy Grade at 28.03 ft Energy Grade at 24.89 ft Hydraulic Grade a 25.99 ft Hydraulic Grade i 22.85 ft Flow Area 4.9 ft= Wetted Perimeter 7.85 ft Velocity 11.45 ft/s Velocity Head 2.04 ft Friction Slope 008850 ft/ft • • • • • Project Engineer:Longview Office c:l..Umw\friendswood existing woodlawn sd.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o1 08/28/03 12:42:26 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Woodlawn 42" storm sewer capacity pressure flow Worksheet for Pressure Pipe Project Description Worksheet Woodlawn Reverse Flow SD Flow Element Pressure Pipe • Method Manning's Formula Solve For Discharge • Input Data Pressure at 1 0.74 psi Pressure at 2 0.00 psi • Elevation at 1 23.29 ft Elevation at 2 21.49 ft Length ,446.00 ft • Mannings Coetic 0.013 Diameter 42 in • Results Discharge 49.54 cfs Headless 3.51 ft Energy Grade at 25.41 ft Energy Grade at 21.90 ft Hydraulic Grade; 25.00 ft Hydraulic Grade: 21.49 ft Flow Area 9.6 ft2 Wetted Perimeter 11.00 ft . Velocity 5.15 ft/s Velocity Head 0.41 ft Friction Slope 002425 ft/ft • I ' Project Engineer:Longview Office c:\...\fmw\friendswood existing woodlawn sd.fm2 Freese&Nichols Inc FlowMaster v6.1 [614oj 08/28/03 12:19:24 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 1 of 1 Shadowbend Storm Drain pipe capacity Calc. Rating Table for Circular Channel Slope Depth Discharge Velocity Flow Wetted Top (ft/ft) (ft) (cfs) (ft/s) Area Perimeter Width (1t2) (ft) (ft) 3.007940 3.00 92.94 10.59 8.8 8.28 2.45 3.008140 3.00 94.10 10.72 8.8 8.28 2.45 0.008340 3.00 95.25 10.85 8.8 8.28 2.45 3.008540 3.00 96.38 10.98 8.8 8.28 2.45 0.008740 3.00 97.51 11.11 8.8 8.28 2.45 • 3.008940 3.00 98.62 11.23 8.8 8.28 2.45 0.009140 3.00 99.71 11.36 8.8 8.28 2.45 3.009340 3.00 100.80 11.48 8.8 8.28 2.45 3.009540 3.00 101.87 11.61 8.8 8.28 2.45 3.009740 3.00 102.93 11.73 8.8 8.2B 2.45 3.009940 3.00 103.98 11.85 8.8 8.28 2.45 3.010140 3.00 105.03 11.96 8.8 8.28 2.45 3.010340 3.00 106.06 12.08 8.8 8.28 2.45 0.010540 3.00 107.08 12.20 8.8 8.28 2.45 3.010740 3.00 108.09 12.31 8.8 8.28 2.45 3.010940 3.00 109.09 12.43 8.8 8.28 2.45 3.011140 3.00 110.08 12.54 8.8 8.28 2.45 3.011340 3.00 111.07 12.65 8.8 8.28 2.45 3.011540 3.00 112.04 12.76 8.8 8.28 2.45 0.011740 3.00 113.01 12.87 8.8 8.28 2.45 • 3.011940 3.00 113.97 12.98 8.8 8.28 2.45 • 0.012140 3.00 114.92 13.09 8.8 8.28 2.45 • • 0.012340 3.00 115.86 13.20 8.8 8.28 2.45 0.012540 3.00 116.80 13.31 8.8 8.28 2.45 • 0.012740 3.00 117.72 13.41 8.8 8.28 2.45 3.012940 3.00 118.64 13.52 8.8 8.28 2.45 • • 0.013140 3.00 119.56 13.62 8.8 8.28 2.45 3.013340 3.00 120.46 13.72 8.8 8.28 2.45 0.013540 3.00 121.36 13.83 8.8 8.28 2.45 3.013740 3.00 122.26 13.93 8.8 8.28 2.45 0.013940 3.00 123.14 14.03 8.8 8.28 2.45 3.000140 3.50 11.90 1.24 9.6 11.00 1.12e-7 0.000340 3.50 18.55 1.93 9.6 11.00 1.12e-7 0.000540 3.50 23.38 2.43 9.6 11.00 1.12e-7 0.000740 3.50 27.37 2.84 9.6 11.00 1.12e-7 0.000940 3.50 30.84 3.21 9.6 11.00 1.12e-7 0.001140 3.50 33.97 3.53 9.6 11.00 1.12e-7 0.001340 3.50 36.83 1.834 9.6 11.00 1.12e-7 0.001540 3.50 39.48 4.10 9.6 11.00 1.12e-7 3.001740 3.50 41.97 4.36 9.6 11.00 1.12e-7 • 0.001940 3.50 44.31 4.61 9.6 11.00 1.12e-7 3.002140 3.50 46.54 4.84 9.6 11.00 1.12e-7 0.002340 3.50 48.67 5.06 9.6 11.00 1.12e-7 3.002540 3.50 50.70 5.27 9.6 11.00 1.12e-7 3.002740 3.50 52.66 5.47 9.6 11.00 1.12e-7 0.002940 3.50 54.55 5.67 9.6 11.00 1.12e-7 3.003140 3.50 56.37 5.86 9.6 11.00 1.12e-7 0.003340 3.50 58.14 6.04 9.6 11.00 1.12e-7 • 0.003540 3.50 59.86 6.22 9.6 11.00 1.12e-7 • 0.003740 3.50 61.53 6.39 9.6 11.00 1.12e-7 0.003940 3.50 63.15 6.56 9.6 11.00 1.12e-7 0.004140 3.50 64.73 6.73 9.6 11.00 1.12e-7 3.004340 3.50 66.28 6.89 9.6 11.00 1.12e-7 Project Engineer: Longview Office c:\...\fmw\friendswood existing woodlawn sd.fm2 Freese&Nichols Inc FlowMaster v6.1 [614o) 09/25/03 02:56:25 PM ©Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 6 of 7 Shadowbend Storm Drain pipe capacity Cale. • Rating Table for Circular Channel Slope Depth Discharge Velocity Flow Wetted Top (ft/ft) (ft) (cfs) (ft/s) Area Perimeter Width (ft2) (ft) (it) • 0.004540 3.50 67.79 7.05 9.6 11.00 1.12e-7 0.004740 3.50 69.26 7.20 9.6 11.00 1.12e-7 D.004940 3.50 70.71 7.35 9.6 11.00 1.12e-7 0.005140 3.50 7213 7.50 9.6 11.00 1.12e-7 • 3.005340 • 3.50 73.52 7.64 9.6 11.00 1.12e-7 3.005540 3.50 74.88 7.78 9.6 11.00 1.12e-7 3.005740 3.50 76.22 7.92 9.6 11.00 1.12e-7 3.005940 3.50 77.54 8.06 9.6 11.00 1.12e-7 3.006140 3.50 78.83 8.19 9.6 11.00 1.12e-7 3.006340 3.50 80.11 8.33 9.6 11.00 1.12e-7 3.006540 3.50 81.36 8.46 9.6 11.00 1.12e-7 3.006740 3.50 82.59 8.58 9.6 11.00 1.12e-7 0.006940 3.50 83.81 8.71 9.6 11.00 1.12e-7 3.007143 3.50 85.01 8.84 9.6 11.00 1.12e-7 3.007340 3.50 86.19 8.96 9.6 11.00 1.12e-7 3.007540 3.50 87.36 9.08 9.6 11.00 1.12e-7 0.007740 3.50 88.51 9.20 9.6 11.00 1.12e-7 3.007940 3.50 89.65 9.32 9.6 11.00 1.12e-7 0.008140 • 3.50 90.77 9.43 9.6 11.00 1.12e-7 0.008340 3.50 91.88 9.55 9.6 11.00 1.12e-7 3.008540 _ 3.50 ' 92.97 9.66 9.6 11.00 1.12e-7 3.008740 3.50 94.05 9.78 9.6 11.00 1.12e-7 • 3.008940 3.50 95.12 9.89 9.6 11.00 1.12e-7 • • 3.009140 3.50 96.18 10.00 9.6 11.00 1.12e-7 . 0.009340 3.50 97.23 10.11 9.6 11.00 1.12e-7 3.009540 3.50 98.26 10.21 9.6 11.00 1.12e-7 3.009740 3.50 99.29 10.32 9.6 11.00 1.12e-7 3.009940 3.50 100.30 10.43 9.6 11.00 1.12e-7 D.010140 3.50 101.31 10.53 9.6 11.00 1.12e-7 D.010340 3.50 102.30 10.63 9.6 11.00 1.12e-7 D.010540 3.50 103.28 10.74 9.6 11.00 1.12e-7 3.010740 3.50 104.26 10.84 9.6 11.00 1.12e-7 0.010940 3.50 105.23 10.94 9.6 11.00 1.12e-7 D.011140 3.50 106.18 11.04 9.6 11.00 1.12e-7 • D.011340 3.50 107.13 11.14 9.6 11.00 1.12e-7 0.011540 3.50 108.07 11.23 9.6 11.00 1.12e-7 3.011740 3.50 109.01 11.33 9.6 11.00 1.12e-7 0.011940 3.50 109.93 11.43 9.6 11.00 1.12e-7 • 0.012140 3.50 110.85 11.52 9.6 11.00 1.12e-7 D.012340 3.50 111.76 11.62 9.6 11.00 1.12e-7 3.012540 3.50 112.66 11.71 9.6 11.00 1.12e-7 0.012740 3.50 113.55 11.80 9.6 11.00 1.12e-7 0.012940 3.50 114.44 11.89 9.6 11.00 1.12e-7 3.013140 3.50 115.32 11.99 9.6 11.00 1.12e-7 3.013340 3.50 116.20 12.08 9.6 11.00 1.12e-7 0.013540 3.50 117.06 12.17 9.6 11.00 1.12e-7 3.013740 3.50 117.93 12.26 9.6 11.00 1.12e-7 3.013940 3.50 118.78 12.35 9.6 11.00 1.12e-7 Project Engineer:Longview Office c:\...\fmw\friendswood existing woodlawn sd.fm2 Freese 8 Nichols Inc FlowMaster v6.1 (614o] 09/25/03 02:56:25 PM 0 Haestad Methods,Inc. 37 Brookside Road Waterbury, CT 06708 USA (203)755-1666 Page 7 of 7