site of proposed gates for Lake Houston on east side of dam

CWA Beginning to Explore New Dam for Lake Houston

2/3/25 – Minutes from the November and December board meetings of the Coastal Water Authority (CWA) suggest that the group is beginning to explore a new dam for Lake Houston, even as it plans repairs and additional gates for the old dam. This post explores the projects and how they fit together.

Discussion in November Board Meeting

During a Board discussion on 11/13/24 about repairs to the old dam, David Miller, PE, the CWA’s Operations Manager, “noted that the Lake Houston Dam is near the end of its design life and CWA is planning for a dam replacement project,” say the minutes.

Don Ripley, PE, the CWA’s General Manager, subsequently noted that repairs to the old dam “would keep the Lake Houston Dam in compliance with State of Texas dam safety requirements.”

Mr. Miller noted that repairs to the Lake Livingston Dam after May floods last year could cost the Trinity River Authority as much as $40 million.

December Minutes Offer More Detail

Then, during the 12/13/24 board meeting, the subjects of repairs to the old dam, a new dam, and additional gates arose again.

Repairs to Old Dam

The December minutes state: “The Lake Houston Dam Repair Project is the $10 million Pre-Disaster Mitigation Grant Project that is being implemented for immediate repairs, including grouting voids below and around the dam structure and repairing the spalled concrete on spillway buttress walls.”

“CWA and CWA’s project engineer, Freese and Nichols, Inc., are currently working on the scope and fee for additional field investigations and design/ engineering work and expect to bring this item to the Board for consideration in January 2025.” (However, the January minutes have not yet been posted.)

“The engineering work will specify the repair locations and approach to be implemented during construction. It is estimated that investigation and engineering work will take approximately six to eight months and construction will take approximately six to nine months in duration.”

Potential Dam Replacement

December minutes also state that, “Planning is also underway for a larger project to replace the existing 75-year old Lake Houston Dam. CWA will have Black & Veatch begin a high-level Lake Houston Dam Replacement Study in 2025.”

Additional Gates

A third Lake Houston Dam project that Directors discussed was additional gates. CWA is planning to add eleven new tainter gates to the dam for an additional 79,000 cubic feet per second of controlled discharge capacity.

site of proposed gates for Lake Houston on east side of dam
New gates would go toward the far end of this earthen embankment, near the existing spillway.

“The design work is underway,” say the December minutes, “and will run through 2026. Current field activities underway include ground and bathymetric surveys. The geotechnical soil borings, environmental investigations including wetlands, endangered species and archeological sites will begin next week.”

“The design team is also scheduling meetings with all of the permitting agencies, including Texas Commission on Environmental Quality (TCEQ), United States Army Corps of Engineers (USACE-Galveston) and Texas Parks and Wildlife Department (TPWD), regarding project details and schedules.”

“CWA met with the TCEQ last week and will meet with USACE-Galveston and TPWD in the coming weeks to inform them of the project details and to obtain an understanding of their respective review schedules and the possibilities of expediting those review schedules.”

“In response to questions from Director Sjolander and Director Huberty, Mr. Ripley stated that this project will increase discharge capacity during flood events which will provide upstream benefits.”

Putting Multiple Projects in Perspective

I reached out to the Coastal Water Authority for more information about the repairs, gate expansion and replacement. I wondered why they just didn’t move full steam ahead on the replacement?

Ripley responded, “CWA does not [currently] have a project to replace the existing dam. CWA is only preparing very preliminary information concerning the possible costs to replace the dam at some time in the future.  Replacement of the dam will involve years of planning and permitting before an actual project could be proposed.”

When you supply drinking water to two million people, you want to make sure you get the engineering right.

Posted by Bob Rehak on 2/3/25

2715 Days since Hurricane Harvey