Common use of Hydraulic Analysis Clause in Contracts

Hydraulic Analysis. a. All hydraulic design shall be design for a 50-year storm frequency design in accordance with the TxDOT’s Hydraulic Manual and U.S. Army Corps of Engineers as applicable, except where variances are permitted in writing by the Owner. b. The Engineer shall review and comment on the hydraulic analysis for each existing and proposed structure location utilizing the HEC-RAS computer program; utilizing ▇▇▇▇▇▇▇'▇ Equation to compute water surface profiles with the inputs of cross-section data, roughness coefficients, and flow rates. Specific steps for the hydraulic analysis are outlined in tasks (b) through (g) below. c. The Engineer shall create the terrain Triangulated Irregular Network (TIN), if not provided by the Owner. This will be developed from a combination of field survey, aerial photogrammetry, and topographic mapping data in the development of a point table. With this point table, an event theme will be created in ArcView, which will create the terrain TIN with 3-D Analyst. d. The Engineer shall create 2-dimensional lines representing the channel centerline, high bank locations, flow path lines, and cross-section locations by locating the various and required poly lines over the terrain TIN develop the watershed layout over the base map e. The Engineer shall create the HEC-RAS GIS import file (ASCII text file); this will involve the correlation of the alignment of the cross-sections with the terrain TIN by extracting the elevations from the -"terrain-TIN atidtreating a3--dimensional cross-section theme. f. For verification of measured elevations, the Engineer shall edit the HEC-RAS GIS import file by selectively replacing the points taken from the terrain TIN at the channel with actual channel points obtained by the field survey. g. The Engineer will review and comment on the accuracy of the HEC-RAS modeling of the existing and proposed structures within the Project facilities authorized in work authorizations as outlined in Article 7 of the Agreement, and compare the hydraulic results to the effective FIS, existing and proposed 100-year flood levels. h. After the HEC-RAS model is satisfactory and the output deemed acceptable, the Engineer shall apply the GIS export function to create the HEC-RAS export file in preparation for the flood plain mapping.