A reservoir under construction west of Houston will serve many beneficiaries, including the rice industry.
By Vicky Boyd
The 40-foot earthen and concrete embankments that ring the 40,000 acre-foot Arbuckle Reservoir are essentially completed, with crews continuing to work on the plumbing that will connect the facility to an adjacent canal and the Colorado River.
The Lower Colorado River Authority, which is building the reservoir, says it still is on track to finish the project near Lane City, Texas, by the end of 2018.
With memories of the worst drought in the state’s history still fresh on their minds, rice producers and allied industry representatives west of Houston say they’re encouraged by the prospects.
“I think especially in a dry year, it will definitely help us,” says Scott Savage, with Triangle Rice Farms near Bay City. During the four-year drought from 2012-2015, the family-owned operation eliminated rice production and survived with one small well, a little bit of corn and milo, and prevented planting insurance. “We’re excited that there’s some type of new facility to help farmers, and we’re excited to have something in the county.”
The water being delivered to farmers from Arbuckle will still be what LCRA calls “interruptible,” meaning farmers pay less but also will be the first to experience delivery cutbacks during a drought. But growers say they hope the new reservoir will significantly reduce the risks of water supply interruptions.
Not only will Arbuckle provide a more reliable water supply to lower Colorado River basin growers, but it also will serve other industries as well as environmental uses in Matagorda Bay. In addition, water managers will have more flexibility, particularly with what are referred to as the Highland Lakes.
The 900-mile Colorado River starts in West Texas and flows to the Gulf of Mexico. The Highland Lakes are a group of reservoirs created by damming the Colorado River above Austin. Among them are Lake Travis and Lake Buchanan, which store water for use in the Colorado River basin.
When users in the lower Colorado River basin need water from the Highland Lakes, orders must be placed seven days or more in advance to allow time to deliver water down 300 miles of river channel. On average, about 30 percent of the water ordered for irrigation is subsequently not taken by the irrigators, due primarily to changed conditions during delivery. Once Arbuckle Reservoir comes on line, water managers will have options to shorten delivery time by supplying water to growers directly from the reservoir or to capture water that is not needed to meet downstream needs.
The increased efficiency of operations will create up to 90,000 acre-feet of additional reliable water supply for the LCRA system.
“It’s going to be a very big help,” said Dick Ottis, president and CEO of Rice Belt Warehouse, which has dryers and warehouses in Bay City, Wharton, Edna and Ganada. During the drought, Bay City and Wharton were particularly hard hit, with volumes dropping by at least 30 percent. “If we use water (out of Arbuckle) and we don’t use a lot of water out of Highlands, then that may satisfy the upper-basin group to leave us alone down here farming rice and other things that we like to do.”
The concept of an off-channel storage facility in the lower basin came about after the LCRA Board of Directors tasked authority staff in 2012 with finding 100,000 acre-feet more water within five years.
“We had done other studies over the years that looked at on-stream storage and off-stream storage, so there was a pretty good body of information,” says Gregor Forbes, LCRA chief construction manager.
So they began looking at building a facility near Lane City that could produce at least 90,000 acre-feet annually along with a groundwater development project near Bastrop, southeast of Austin, that will yield an additional 10,000 acre-feet.
Steve Balas, an Eagle Lake rice grower, is a current LCRA board member and served during the initial reservoir planning stages. As with any large project, he says some members of the public objected. “As the drought went along, it got easier,” Balas says.
As a farmer, he sees Arbuckle helping particularly south of Wharton where saltwater intrusion into groundwater makes drilling wells infeasible.
Location, location, location
After completing siting and cost analyses studies, LCRA settled on eight contiguous tracks of land comprising 1,100 acres near Lane City. Fortunately, Forbes says, the authority was able to obtain all the land from willing sellers.
Factoring into the location was its roughly half-mile proximity to the Colorado River. The site’s geology also lent itself, significantly reducing the amount of materials that needed to be trucked in to build structure embankments.
Of the 8 million cubic yards of clay and sand needed, over 6 million were on site and just needed to be moved around.
Through an arrangement with LCRA, the Texas Water Development Board issued $255 million worth of 30-year low-interest bonds to fund the project. LCRA is responsible for retiring the debt.
As part of the project, five pumps and relifts can transfer water from the Colorado River through pipes and canals into the reservoir. The reservoir will operate year-round, and LCRA water managers will continue to meet environmental flow obligations for the river and Matagorda Bay.
Water rights also limit the amount the authority can divert.
At the same time, water managers will be able to send water from the reservoir into the Colorado River. On the other side of the reservoir is an outlet to deliver water into an existing canal for transfer to other water users and customers.
Project general contractor Phillips & Jordan of Nashville, Tennessee, began construction in earnest in early 2016, and Forbes says he’s expects the project will be operational by the end of 2018.
Roughly shaped like a square, the reservoir is about 50 feet at its deepest and is designed to hold about 40 feet of water. Specially designed concrete wave walls at the top of the earthen embankments minimize erosion caused by lapping water. The project is designed to withstand a Category 5 hurricane.
Making more efficient use of a natural resource
Arbuckle is considered an off-channel facility, meaning no dams have backed up a waterway to create a lake. This reduced environmental impacts and allowed for more streamlined permitting, Forbes says.
The location in the lower basin taps into the region’s historically higher rainfall than the Highlands Lakes region.
The Wharton area receives about 50 inches of rain per year compared to the roughly 30 or so inches of annual rain received in Austin.
“It was a missed opportunity to not have something here, so we’re really excited about creating storage in the lower part of the river basin and making more efficient use of a natural resource,” Forbes says.
The reservoir itself will hold about 40,000 acre-feet, and water managers plan to fill it multiple times a year to create the 90,000 acre-feet of additional supply, thereby increasing LCRA’s overall supply by about 15 percent annually. The actual amount will depend on the weather.
If it had been online last year, Forbes estimates it could have been filled and refilled four to five times.
Arbuckle also marks the first water-supply facility built in the Colorado River basin in decades, Forbes says. It is intended to be operated solely for water supply storage and will not be for recreational or flood-control uses.
Originally referred to as the Lane City Reservoir, the project was dedicated as the Arbuckle Reservoir in late 2017 to recognize former LCRA board member J. Scott Arbuckle, who was instrumental in getting the project built.