Freese and Nichols provided hydrologic and hydraulic modeling, engineering analyses, CLOMR and LOMR preparation, and construction documents preparation for a 30-foot tall concrete dam and floodwall. The hydrologic and hydraulic analyses covered more than four square miles of the Upper Walnut Creek Watershed and nearly five miles of stream. The project will protect seven houses that are in or at-risk of the ultimate 100-year floodplain and will reduce downstream erosion. The dam included 45 post tension bar anchors to provide stability and to reduce construction costs.
The project also included relocation of approximately 850 linear feet of existing 24-inch ductile iron wastewater line, and design of a new wastewater grinder pump station, 200 feet of force main, new manhole, and 150 feet of new eight-inch gravity line tying into the existing sewer system. The project was designed so that it could be constructed under a nationwide 404 permit.
City of Austin
Construction Services, Dams and Levees, Environmental Science, Permitting, Stormwater, Structural