By Martha Underwood
Killeen Daily Herald
The last section has been laid again in the pipeline from Stillhouse Hollow Reservoir to Lake Georgetown.
The pipeline will transfer water as needed to the reservoir in Williamson County, where there is a rapidly growing population.
Originally constructed in 2000 and 2001, pressure testing showed that more than half of the 28-mile pipeline failed to meet engineering standards, said Judi Pierce, Brazos River Authority spokeswoman.
The contractors dug rectangular trenches to bury the 48-inch diameter pipes, then refilled with "the wrong grade of sand and gravel, so the pipe smashed like a pancake," Pierce said.
BRA controls distribution of the conservation pool, which stores water for human consumption, in Stillhouse Hollow, Georgetown and the other Army Corps of Engineers lakes in this area.
The reconstructed pipeline is completely laid, and hydrologic pressure testing will begin in mid-July, said Randy Wooten, BRA director of technical services over this project.
The pipeline itself cost $20 million, Wooten said. He estimated the entire project, including the water intake structure, will cost $36 million to $38 million. "The (contractor's) surety company is picking up the (reconstruction) cost, so there is no added cost to the customers," he said.
BRA provided project financing to the five Williamson County wholesale customers who have water rights in Stillhouse Hollow. They are the cities of Georgetown and Round Rock, Brushy Creek Municipal Utility District, Chisholm Trail Special Utility District, and Jonah Water. These entities pay the debt service and contract with BRA to operate and maintain the system.
Georgetown is a relatively small lake in a high-growth area, Wooten said. "The most cost-effective way to provide them water was to build a pipeline from Stillhouse Hollow," he said.
When needed, the maximum water volume those customers can take from Stillhouse is 44,000 acre-feet per year, Wooten said, but the BRA has the ability to provide water from other locations as well.
The conservation pool for drinking water in Stillhouse Hollow holds 235,700 acre-feet of water when filled to 622 feet elevation, said Dan Thomasson, U.S. Army Corps of Engineers lake manager for Stillhouse Hollow and Belton lakes. An acre-foot is the amount of water that would cover one acre of land to a depth of one foot, or about 325,500 gallons.
"There is more than enough water in Stillhouse Hollow Lake to meet Bell County's needs for the next 100 years," Pierce said. "Williamson County is part of our basin, so piping water into Lake Georgetown is not pumping it out of the basin."
There has been enough rain so that BRA's Georgetown customers did not need water from Stillhouse Hollow during the past few years, Pierce said.
"Georgetown Lake's conservation pool is full today," said Wooten. The lake elevation was 791.32 feet Wednesday, which is about four inches higher than the top of the conservation pool. Even if the pipeline was in service, no water would need to be pumped from Stillhouse Hollow today, he said.
BRA officials think the decision to pump water out of Stillhouse Hollow will be made when Lake Georgetown drops to half its conservation pool capacity, based on today's population, Wooten said. He noted that increased population could cause that percentage to shift upward.
Contact Martha Underwood at firstname.lastname@example.org