Agenda - 06-18-2013 - 7f - Laserfiche WebLink

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113 Hangle egi na ��n��'��P„�� Project IIC v O0pIin iin Scope of Work Field and Office Data Collection: A field reconnaissance visit to the project will be conducted to verify existing drainage structures and features, identify land use, and define surface drainage flow patterns. During this visit each drainage outfall will be located, described, and evaluated for any stability, and or capacity concerns. As appropriate for the project, local resident and/or DOT and City maintenance personnel will be interviewed to determine the presence of recurring drainage problems, and to determine historical high water information. Potential environmental impacts, such as fill in wetlands or stream relocation, will be noted. For major drainage structures that exist within the project limits, research will be conducted to obtain previous bridge/culvert survey reports, bridge inspection reports and scour studies. Flood zone status will be determined and stream gage data will be obtained if applicable. Bridge and Box Culvert Size Structures: Preliminary review indicates that there will be approximately fourteen bridge or box culvert (structures with a conveyance greater than a 72' pipe) size crossings. Hydrologic and Hydraulic analysis of these structures will be performed to determine size, location and hydraulic performance. Bridge scour analysis will be performed on the bridge structures for use in determining foundation cost. Designs will be documented in plan and profile and in the detailed drainage report. Nine of these sites are located in FEMA Designated Flood Hazard Zones. Existing FEMA models will be obtained from the North Carolina Floodplain Mapping Program (NCFMP). These existing models will be used to insure designs meet FEMA regulations and to determine the possible FEMA approvals that will need to be obtained prior to construction. This information will be documented in the detailed drainage report. The following Streams are located in FEMA Designated Flood Hazard Zones: Stream Name AA Plan Sheet Approx. Station Potential Structure Study Type/DFIRM Meeting of the Water B-02 65+00 Culv. Extension Limited Detailed 9788 Chapel Creek B-03 96+00 Culv. Extension Limited Detailed 9798 Little Creek C1-04 120+00 Bridge Limited Detailed 708 New Hope Creek D-06 357+00 Bridge Redelinated 800 Sandy Creek D-07 363+00 Bridge Redelinated 800 Sandy Creek D-08 380+00&384+00 Bridge Redelinated 800 Sandy Creek E-01 113+00 to 133+00 Culvert Redelinated 811 Sandy Creek Trib E-01 122+00 RT Culvert Redelinated 811 Sandy Creek E-02 172+00 Culvert(? ) Redelinated 811 Un-named Trib. C1-01 40+50 Culvert No Study Un-named Trib. D-02 231+00 Culvert No Study Un-named Trib. D-03 242+00 Culvert No Study Un-named Trib. D3-03 95+25 Culvert No Study Un-named Trib. E-04 191+50 Culvert No Study Pipes,Storm Drain Ditches and Stormwater Management Various analyses will be performed and will include cross pipe analysis and design, closed storm drainage system design modifications to existing systems, underdrain design, ditch and channel capacity analysis and stability recommendations, outlet energy dissipater design, and stormwater best management practice (BMP) design. Appropriate output files and reports will be generated and included in the Detailed Drainage Report. Conceptual drainage designs will also be provided for the Yard & Site, and provisions will be made for the drainage for the eight park and ride lots. All proposed drainage design will be documented in plan sheets and profiles Durlhnarn Orange I,,.ligllhnt Il ailll Transit (Project � June 2013. �9..4 DIRAF.F