Alliance Water received approval for a $213.4 million new water supply project along the I-35 corridor.
Alliance Water received approval from the Texas Water Development Board (TWDB) in August 2017 for a $213.4 million new water supply project along the I-35 corridor between Austin and San Antonio. Funding for the project will come from the State Water Implementation Fund of Texas (SWIFT). The “Phase 1B Program” is now in the process of selecting a design consultant, with a target of beginning construction in 2020.
“This is an important project between Austin and San Antonio, providing 15,000 acre feet of water per year to a fast growing region,” explained Graham Moore, executive director of the Alliance Regional Water Authority. “It demonstrates that the cities and sponsors have worked together to create this water supply. It's a good example of how partnerships can work among public entities.”
How much is an acre foot of water? One (1) acre foot equals 43,560 cu. ft. or 325,851 gal. of water. The Texas Water Development Board projects a 34 percent population hike over a 16-year span from 2014 to 2030. The regional and state water plan data estimates an increase of 1.44 million in the population along the Austin — San Antonio Corridor.
Long term, Alliance Water anticipates yielding 35,690 acre-feet per year of water to its sponsors, which include the cities of San Marcos, Kyle and Buda. To reach this output, another expansion will take place in the next 20 years. The sponsors all currently utilize a combination of local groundwater from the Edwards Aquifer and surface water from Canyon Lake. The need for a new supply is 100 percent driven by the population growth in the region.
The Phase 1B project aims to initially produce, treat and deliver approximately 5,500 acre-feet per year, growing to 15,000 acre-feet per year through the future addition of Carrizo-Wilcox wells in Caldwell County and water treatment trains. The well field will continue to be expanded through time as demand grows through the addition of new groundwater wells to increase the available yield in accordance with Alliance Water's permits. Alliance Water's schedule calls for treated Carrizo water to be delivered to all the sponsors in the year 2023.
The Phase 1B infrastructure is expected to be comprised of the following components: Four Carrizo groundwater wells; 20,000 linear ft. of 16 in. to 42 in. raw water pipelines with isolation valves, and a water treatment plant.
Approximately 95 mi. of 12 in. to 36 in. pipeline with isolation valves will be used. Trenchless pipeline installation will take place under any waters of the United States and at significant roadway crossings. Metering stations will be put in at all points of delivery with chlorine analyzers.
Plans call for a 20-ft. wide permanent water line easement and 30-ft. wide temporary easement where single lines are planned for the duration of the project, and 35-ft. wide permanent and 30-ft. wide temporary for locations where two pipelines are ultimately anticipated.
A smaller but related project, Phase 1A, broke ground in late February. This $12 million job is for laying 2 mi. of 24 in. pipeline and will be constructed by Central Road & Utility of Austin.
Formed in January 2007, Alliance Water (formerly the Hays Caldwell Public Utility Agency) is comprised of the cities of San Marcos, Kyle and Buda, along with the Canyon Regional Water Authority, which represents County Line Special Utility District, Crystal Clear Water Supply Corporation, Green Valley Special Utility District and Martindale Water Supply Corporation. For more information, visit www.alliancewater.org.
Construction Cost Estimates:
Transmission Mains $150,000,000
Well Drilling $3,000,000
Raw Water Lines
Well Infrastructure $11,500,000
Water Treatment Plant & High Service Pump Station $11,500,000
Booster Pump Station $7,000,000
Administrative/Operations Facility $2,100,000
Delivery Points (eight sites) $2,400,000