Hydraulic Analysis. To determine the impacts associated with the project, floodplain hydraulic geometric models will be prepared for the portion of the creek system where the bridge will be located. The analysis will extend approximately a minimum of 1,000 feet upstream and downstream of the proposed bridge location in order to adequately assess project impacts. Available previously prepared floodplain hydraulic and floodway analysis performed by other investigators or agencies will be reviewed to ensure consistency with results and the hydraulic model variables. The floodplain evaluation will include the analysis of two different conditions, (1) baseline condition or an effective floodplain model reflecting the existing condition of the natural floodplain prior to the proposed bridge construction, and (2) developed condition or modified floodplain analysis, which includes the modifications of the floodplain for the proposed bridge crossing and potential encroachment within the floodplain. The hydraulic analysis will establish the water surface profiles and hydraulic parameters, which identify the characteristics of the floodplain. The floodplain will be evaluated utilizing the one dimensional water surface profile program developed by the Army Corps of Engineers, HEC-RAS. The hydrologic data for the 100-year flowrates which will be incorporated into floodplain model will be based upon previous hydrologic information and no additional regional hydrology will be performed as part of this study unless through separate addendum. Channel geometric data will be obtained from digital topographic mapping provided by OCPW for this project.
Appears in 5 contracts
Samples: Professional Services, Amendment No.1, Professional Services
