Hydrilla Management
Over the past years the hydrilla coverage had reached approximately 300 acres in 2007 choking coves and shoreline along most of the lake.

Texas Parks and Wildlife recommended an integrated approach to treating the hydrilla that included herbicide and the addition of triploid grass carp that would equal 10 carp per acre of hydrilla.

In April 2007 the city added 2,500 triploid carp and that was followed by an extensive herbicide treatment in June. Then the July 2007 floods resulted in muddy water which lasted for several months and blocked sunlight from reaching the plants.

The combination of all these factors (carp, chemicals and muddy water) has resulted in the reduction of hydrilla to only trace amounts per the August 2008 survey by TP&W. Due to such small amounts TP&W will not recommend further chemical treatment at this time.

Grass Carp:

• are sterile and cannot reproduce.
• feed only on plants, not on fish eggs or young fishes.
• feed from the top of the plant downward; however, where all submersed vegetation has been eliminated, the water can become turbid as hungry fish eat the organic material out of the sediments.
• go dormant during the winter and resume intensive feeding when water temperatures reach 68°F.
• live for at least 10 years and probably longer in Texas waters.
• grow rapidly and may exceed 60 pounds.
• are difficult to catch with conventional fishing methods.