The Brazos River Authority Board of Directors, at its bimonthly meeting, approved upcoming projects to help extend the life of the agency's oldest dam.
Located on the main stem of the Brazos River, northwest of Fort Worth, resides Possum Kingdom Lake, a water supply reservoir built by the BRA in 1941. Holding back 540,000 acre-feet of water in that reservoir is the lake's Morris Sheppard Dam.
Possum Kingdom Lake and its more than 200 miles of cliff-flanked shorelines provide water to cities, water districts, water supply corporations, agricultural users, irrigators, steam electric generating facilities, manufacturing entities, and mining operations. This means that maintaining the structural integrity of and extending the life of the Morris Sheppard Dam is of utmost importance to the BRA.
At their meeting in September 2025, the Board approved a roughly $1.7 million contract with Walter P. Moore for engineering services for the dam.
Flashback to 1987, when an inspection of the dam discovered the buttresses at the south end of the spillway had
moved downstream up to 4.5 inches, said BRA's Chief Projects Officer Mike McClendon. As a result, a myriad of actions were taken to fix the issue. One of those measures included the addition of a monitoring device called a weir box to measure the small flow through the dam, McClendon said. That flow is collected in a pipe, measured monthly at the weir box, and then discharged downstream. The flow equates to a very small amount of water, roughly 2 cubic feet per second, he said. Seepage through a dam is normal and not considered a safety issue, provided conditions remain unchanged, McClendon said. The measurement of cubic feet per second represents the rate of water movement, indicating the volume of 1 cubic foot passing a given point in 1 second.
Since that monitoring system was put in place, there have been no measured or noticeable flow fluctuations, he said. However, it's time to study the structure to see if its age requires modifications or replacement to ensure the continued operation and maintenance of the dam safely and responsibly.
Also at the meeting, the Board approved $728,000 for engineering services with Simpson Gumpertz & Heger for maintenance of the PK dam's Controlled Outlet Conduit, or COC.
In 2012, the BRA installed a large pipe within the dam structure to release smaller amounts of water. There are four ways water can be released from Morris Sheppard Dam, with the COC being one. The three "low flow gates" allow a release of up to 100 cubic feet per second each and are regularly used to pass the required environmental flows downstream. Then there are, of course, the more well-known bear-trap gates, which, depending on the streamflow and lake elevation, allow each gate to pass up to 9,600 cubic feet per second of water when open. Finally, there is also the uncontrolled spillway, a large flat area cut into the rock on the south side of the dam. The uncontrolled spillway is capable of passing floodwaters in amounts larger than the nine spillway gates can handle. In the history of Morris Sheppard, such a flood has not occurred, but the facilities are in place if needed.
The COC allows the BRA to release a maximum of about 3,500 cfs and manage lake levels before and immediately after high-flow events, said Blake Kettler, BRA's chief planning officer. They also offer the ability to release water in amounts between the low flow gates' capability of 150 cfs each and the bear-trap gate's 9,600 cfs. Finally, due to the outlet's location, the COC provides the ability to release water from the Morris Sheppard Dam should the lake level drop more than 13 feet during periods of drought.
The COC incorporates a 42-inch ring jet valve, a 78-inch ring jet valve, and a pipe approximately 200 feet long, varying in size from 42 to 144 inches. During a more recent inspection of the COC, some maintenance needs were identified, and the engineering services with Simpson Gumpertz & Heger will design repairs to extend the life of this vital infrastructure.
Interested in learning more?
- For a complete list of actions the Board of Directors took, go here.
- Watch the full Board meeting here.
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For any additional questions, email us at information@brazos.org.