BRA landmark permit gets first big update

The Brazos River Authority supplies water to communities throughout the basin, thanks mostly to reservoirs built from the 1930s to the 1980s.

But there’s one water right permit that provides as much reliable water as a reservoir, but without the reservoir. It comes from somewhere totally different.

Math.

The Texas Commission on Environmental Quality (TCEQ) granted the System Operation (SysOps) Permit to the BRA in November 2016. Now, a decade later, the permit is undergoing its first major permit-required update.

A water right is permission from the state, through the TCEQ, to use surface water. This could mean storing water in a lake or taking it from a river. Water rights granted to the BRA allow the BRA to supply water to cities, farms and industries across the region.

The SysOps Permit made about 100,000 acre-feet of additional water available for use within the Brazos River Basin. That is about the same amount of reliable water supply as is provided by Lake Belton.

“This made the System Operation Permit a significant increase in long-term water supply for the basin without the construction of additional infrastructure,” said Aaron Abel, BRA’s water services manager.

Texas’ population is expected to double over the next 50 years, according to the Texas Water Development Board. The BRA is always looking for new water sources and ways to use water more efficiently to meet the needs of municipalities, water districts, water supply corporations, agricultural irrigators, steam electric generating facilities and manufacturing entities.

The Brazos River Basin begins in New Mexico, spans all or part of 70 Texas counties, and empties into the Gulf near Freeport. On average, nearly 6 million acre-feet of water flow past the last monitoring station on the river into the Gulf each year. The permit helps the BRA use that water more efficiently.

System Operation Permit

The SysOps Permit is based on three key points. First, coordinating how water is stored or released in the BRA’s reservoirs to help reduce losses and increase the available supply. Second, augmenting natural flows downstream of the reservoirs with reservoir releases during dry times to create a reliable supply. Third, incorporating treated wastewater effluent entering rivers and streams throughout the basin.

The BRA holds water rights for 11 existing reservoirs - Possum Kingdom, Granbury, and Limestone, which are owned by the BRA, and Proctor, Whitney, Aquilla, Belton, Stillhouse Hollow, Georgetown, Granger, and Somerville, which are owned and operated by the Corps. The SysOps Permit is the BRA’s newest water right and, among other things, integrates the storage and use of the reservoir supplies.

The SysOps Permit may have been the first of its kind in the state, but system operations aren’t anything new. In fact, the BRA was granted the System Order in 1964, which allows the BRA to operate its reservoirs as a system – meaning that the BRA can preferentially use reservoir storage in wetter parts of the basin to meet downstream water demands while holding water in drier parts of the basin.

“The System Order allowed us to manage the system holistically,” said Peyton Lisenby, BRA senior water planner. “Instead of counting usage from each reservoir separately, we account for it against the total system supply.”

“The name of the game is reducing the losses, right? When it comes to system operation, what you are trying to do is instead of operating each of your reservoirs independently, like their own island of water, for whatever supplies are needed from that location, you can operate reservoirs acknowledging the existence of other reservoirs,” Lisenby said.

That means understanding each reservoir’s unique features, such as its size, how much water flows in from upstream, and whether it’s in an arid or humid part of the basin.

Water that flows into these reservoirs can be lost if it must be released due to a lack of storage space. SysOps tries to use the water stored in the reservoirs that fill more readily, like those in rainy areas, first to reduce water losses. Hydrologists then apply that concept across the 11 reservoirs in the BRA’s Water Supply System. By prioritizing the use of reservoirs that fill frequently, this process reduces system losses and optimizes supply across the BRA’s 11-reservoir system.

Additionally, reservoir supplies can leverage the water already in rivers – the natural, run-of-the-river flows. This natural flow that originates downstream of the BRA's reservoirs during wet times is not reliable on its own during dry times. However, these flows can be augmented by releases from BRA reservoirs upstream during dry times to make them reliable throughout the year.

It wasn’t until the TCEQ developed sophisticated water availability models that the BRA could demonstrate the availability of additional water generated by system operations.

Wastewater treatment plant return flows

The SysOps Permit incorporates treated return flows that are released back into rivers and tributaries by wastewater plants.

“Now, as soon as it's discharged, as soon as it's dumped back into a river, that's the state's water again,” Lisenby said. “And naturally, you have to ask the state permission if you want to use it.”

There are thousands of wastewater treatment plants in Texas, so at any given time, some amount of the flows in a major waterway are sourced from wastewater treatment plant return flows. These return flows create another reliable source of water. The permit lists which return flows can be counted towards BRA’s supply.

Of course, things change over time. Wastewater treatment plants are expanded, decommissioned, or relocated. This is, in part, why the update of the BRA’s Water Management Plan is important.

The Water Management Plan

The SysOps Permit requires a Water Management Plan and a Technical Report to explain the details of the permit. These documents describe the rules, analysis, and background for how everything works.

The BRA’s website features a dedicated section for the SysOps Permit and Water Management Plan, recently updated with documents, FAQs, and an easy-to-follow timeline of the Permit’s initial permitting process.

Since the initial Water Management Plan was developed in 2012, there’s a wide variety of technical information, like hydrology, customer demands, system infrastructure, and so forth, that needs updating.

The updated version will also include a water dedication. In 2024, the BRA dedicated 6,035 acre-feet of the SysOps Permit’s firm water supply to the Texas Parks and Wildlife Department to support environmental needs.

Once the updates are completed, the BRA will submit them to the TCEQ. The updated documentation will be reviewed by TCEQ, a process that could take up to three years. After that, a full notice of the application will be issued to the entire Brazos basin.

For more information on the System Operation Permit and the Water Management Plan, go here.