Projects: Watershed Hydrology & Hydraulics

Onion Creek Flood Study, Austin, Texas

Loomis Austin contracted with the City of Austin to perform a determination of optimal flood control solutions for a residential area along Onion Creek in which more than 800 homes were determined
to be located in the Onion Creek floodplain. Previous flood frequency analyses performed in the 1970's at the time of the residential housing construction had neglected several very extreme flood events over the past 100 years. Re-performance of flood frequency analyses and updated hydrologic model implementation determined that the 100-year design flow was substantially higher than originally determined. Loomis Austin performed detailed field and hydrologic/hydraulic parameter reconnaissance to support updating of the most recent Corps of Engineers - Fort Worth District
HEC-RAS model of the subject reach. Flood control alternatives considered included channelization, flow diversion across the downstream golf course, levee construction, and voluntary and mandatory property buyout.

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