November and December's rainfall has done little to raise the level of Lake Travis, the main source of water for residents of Cedar Park and Leander. However, the rain has allowed the cities to push back parts of the cities' shared Drought Water Intake Contingency Project.
The Texas Commission on Environmental Quality also approved changes to the Lower Colorado River Authority's water management plan. The changes allow the authority to cut off water to rice farmers downriver if lakes Buchanan and Travis drop below 850,000 acre-feet of water, which translates to approximately 634,000 acre-feet for Lake Travis.
To ensure Cedar Park and Leander are able to draw the water the cities need, the cities have teamed up to build an underwater pipeline that will move their raw water intakes—currently at 620 feet above mean sea level—deeper in Lake Travis to the Colorado Riverbed.
"That action has already allowed us to extend the completion of the deadline of what was March to April. However, the most recent LCRA lake level projections released just (several) weeks ago, the December projections, still show a possibility of the lake levels dropping to the point that LCRA would trigger the mandatory pro rata curtailment this summer," said Sam Roberts, Cedar Park assistant city manager.
Mandatory pro rata curtailment would mean LCRA's firm water customers, such as municipalities, would be required to reduce water usage by 20 percent, and there would be stiff penalties for noncompliance.
Constructing the pipeline
The Drought Water Intake Contingency Project Phase A is under way—an underwater pipeline that will connect to a floating intake barge in Phase B of the project. Contractor Excel Construction engineered the method, where seven 200- to 900-foot sections of pipe—3.7 inches thick and 42 inches in diameter—are constructed on dry land. Each segment has 8,000-pound ballasts placed every 20 feet along the length of the pipe. The ends of the sections are capped, and since there is air trapped inside the pipe segments, these sections float. When the sections are all ready, a crane will pick up the pipe sections and bolt them together. Then the connected pipe will be taken to its desired location, the ends will be opened, water will flush out the air and the pipeline will sink to the river bottom.