The “lake” levels at Dam 7 have noticeably dropped this summer in large part due to the extreme heatwave plaguing Central Texas combined with a third year of drought. As rainfall returns and the temperatures cool off the “lake” will gradually fill back in.
The “lake” was created as a byproduct of the regional flood control dam. The dams across the District were created with a sediment pool and storage area for runoff from rainfall whether it be a small event or a larger storm. The islands that are now visible are representative of the sediment pool feature of the dam. Some dams with clay soils have a permanent pool of water filling the remaining portions of the sediment pool: these “lakes” serve as a community amenity when located in parks. The dams act by holding the water back and releasing it slowly over time. The “lake” water at Dam 7 is also used for irrigation of the park and the golf course. This irrigation is supplemented with reuse water. Both utilizing the reuse and “lake” water help conserve precious drinking water during drought.
The District visited the site last week and will follow up with more technical inspections this week. Our flood mapping tool can be utilized to access reports from USGS where you can see precipitation and lake levels over time. Both Dam 6 at Lake Creek Park upstream and Dam 7 at Brushy Creek Lake Park are at or near record lows based on ten years of collected data.