Why a New Dam
Dam 101 is one of the Lake Creek Flood Mitigation Projects (Dam 101, Dam 102, and 620 Quarry modifications) designed to substantially reduce flooding in Williamson County’s largest damage center. Construction of Dam 101 will reduce flooding risks to over 1,000 residents and improve emergency access and response times during flooding events. Under the design models (USGS 2010 Rainfall) flooding reductions range from 6 to nearly 4 feet within the most at risk areas of the Greater Round Rock West neighborhood to just after AW Grimes where Lake Creek joins Brushy Creek. (Please note current AW Grimes road flooding is due to Brushy Creek which is not affected by this project.) Collectively the Lake Creek Flood Mitigation projects reduce flooding to the maximum extent practicable; Dam 101 is the workhorse of the three projects, and must be accomplished first.
Several neighborhoods in the District were built before the area had FEMA flood mapping including Round Rock West that was built in the early 1970's before FEMA floodplain maps and the substantial upstream development existed.
Several flood events occurred during the 1970's that spurred the City of Round Rock to inquire about FEMA flood mapping and the NFIP Program.
The area has continued to experience sporadic major flooding events including Tropical Storm Hermine in 2010.
Since then, this area of Central Texas has experienced tremendous growth and development that have increased both the volume and velocity of runoff in the Lake Creek watershed.