AUSTIN (KXAN) - An invasive water plant that can choke out other plants and snag boat propellers is finally under control in Lake Austin.
Hydrilla has been present in the lake since 1999 and reached a historic high coverage of more than 600 acres in February 2013. The low flow brought on by the ongoing drought and warmer water temperatures helped the plant thrive.
"During the drought, the water temperatures on Lake Austin warmed up and hydrilla basically took off," said Mary Gilroy, City of Austin Watershed Protection Department.
In an effort to control the plant, the city, working with the Texas Parks and Wildlife Department, brought in sterile Asian grass carp . The fish target hydrilla as their main food source.
"When we saw the hydrilla increasing we had to slowly increase the number per acre. We got up to 55 grass carp per vegetative acre of hydrilla," said Marco De Jesus, Texas Parks and Wildlife Department.
A September survey found no hydrilla in the lake. The removal of the plant also helped milfoil, a less aggressive exotic plant, expand. Milfoil provides benefits that include providing a aquatic habitat for fish and other wildlife while helping maintain good water quality, the city said.
"We've also taken a conservative approach to this because we also want to maintain fish habitat for our anglers," said De Jesus.
The city warned that while the hydrilla is under control, it is likely not eradicated. They say changes in water flow or temperature and a natural decline in the grass carp population could allow the plant to re-sprout.
"The idea that the hydrilla is gone for good is really erroneous," said Gilroy. "It isn't gone. There are still roots and tubers under the lake floor that will continue to sprout."
The carp already in the lake will feed on the sprouts and the city hopes they will contain the hydrilla for several years. The densely growing plant also impacts flood flow and water intakes.
Mack Brown's attorney and the university's new athletics director say the Texas coach has not resigned, denying a report that Brown was ready to step down after 16 seasons with the Longhorns.
A large majority of the crowd that poured into Austin City Hall on Tuesday night was disappointed with the Parks and Recreation Department's decision to approve a smaller off leash area at Auditorium Shores.
The top prosecutor in Travis County found herself on the witness stand Tuesday to answer questions about her professional and personal history along with her history of alcohol.
A proposal to build a highway in south Austin is getting mixed reviews from neighbors.
An Austin man has been convicted in a human smuggling case in which a teen says she was forced to wear revealing clothes and sexually assaulted while bound for New Jersey.
An historic early December cold spell is slowly waning, but temperatures will remain well below average for a couple more days.