Promoting Safety and Awareness in Williamson County Through a Flood Monitoring System (FMS)
When the 23 dams in the Upper Brushy Creek watershed in southern Williamson County were built by the U.S. Soil Conservation Service in the 1960s, they met all safety standards for earthen dams in sparsely populated areas. Now, 21 of those dams provide flood control for one of central Texas’ fastest growing populations and, due to increased potential risk to the public (risk creep), are classified as high hazard dams.
In 2000, the Upper Brushy Creek Water Control and Improvement District (WCID) was directed by the State of Texas to bring the 21 high hazard dams into compliance with State Dam Safety Criteria. The WCID Board determined that each of these dams should safely pass a 100-percent probable maximum flood (PMF) storm event, which is nearly 44 inches in 24 hours in Central Texas. Along the way, the WCID implemented a flood monitoring system (FMS) at all 21 dams.
Details of an FMS Installation
A typical FMS installation consists of devices to gauge lake levels and rainfall, and system diagnostic tools to remotely monitor the status of the system. A central processing unit calculates and stores data locally for up to three months and transmits the data through a two-way, licensed public safety radio frequency. The remote setup is powered by a solar array and battery, which has a two week time of autonomy designed for prolonged, overcast days. Remote data is sent every 15 minutes to the WCID’s base station and is shared with local emergency management and response officials through the FMS website.
Positive Feedback Results in Desire for Expanded Coverage
The cities, county and emergency management service providers involved in this project have responded positively to the FMS and may consider expanding its coverage via installation of a separate monitoring system for low-water crossings and other flood prone areas.
For now, the WCID is using their current FMS to coordinate with the City of Austin and the Lower Colorado River Authority to share rainfall information and to immediately expand their coverage and prediction of severe weather moving in from north of their jurisdictions.
Lake levels and rainfall information is currently available to the public online at: www.ubcwcid.org. This public website helps promote flood awareness in the region and allows residents to monitor local weather conditions.
For More Information
Additional information on FMSs can be found through the Automated Local Evaluation in Real Time (ALERT) Users Group.