Res 1993-101 - Laserfiche WebLink

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;2:lf3 (2) areas subject to overflow of storm sewers or channels as indicated by high water marks and indication of overflow; (3) channel and overbank roughness characteristics; (4) areas of erosion; (5) areas with excessive vegetation; and (6) accumulated sediments/debris. 1.4.4 Deliver to CITY a technical memorandum including the reconnaissance survey notes. 1.5 TASK 5 - FIELD SURVEYS The ENGINEER shall: 1.5.1. Present information gathered on the location of storm sewer infrastructure to the CITY for review. 1.5.2. Following CITY's review and approval of the reconnaissance survey, authorize the completion of a field survey of the infrastructure identified during the reconnaissance survey. 1. 5.3 Collect field information as follows: . (1) curb inlet dimensions and locations; (2) pipe conduit drainage network data showing diameter, pipe materials, flow line elevations and network configuration; (3) detention basin storage-elevation data; (4) channel cross-section data; and (5) stream crossing data (culverts and bridges) including dimensions/shape of waterway opening, low chord elevations, upstream/downstream invert elevations, headwalls/wingwalls, orientation to the channel, and top-of-roadway elevation. The field survey will not include driveway culverts or roadway culverts less than 24" in diameter unless required for input to the hydraulic models developed in Paragraph 1.6. 1.5.4 Deliver to the CITY a technical memorandum including copies of field survey notes. 1.6 TASK 6 - DEVELOP HYDROLOGIC AND HYDRAULIC MODELS The ENGINEER shall: 1. 6.1 Develop hydrologic and hydraulic models which will determine the adequacy of the storm drainage system and will simulate runoff and flow in the secondary system. The tributary watershed areas indicated on Exhibit "A" define the project study area. 1. 6.2 Utilize the hydrologic/hydraulic model SWMM developed by the Environmental Protection Agency (EPA) to simulate flood flows and resultant water surface elevations under existing and future land use ::::onditions, justify use of the SWMM model on this project, and - calibrate models against historical data where available. 1. 6.3 Make maximum use of any existing hydrologic/hydraulic modeling databases from previous drainage studies in order to limit the amount of additional field survey work required for verification of channel configurations and drainage structures, and the amount of model development effort. 1. 6.4 Develop stormwater models to represent the secondary drainage system inside the City limits as a series of subwatersheds linked by pipes and/or open channels. Each subwatershed should cover a tributary drainageway that exhibits relatively homogeneous physical -3-