City Gets Favorable Ruling on BCR for Lake Houston Gates Project

During Harvey, 16,000 homes and 3,300 businesses in the Lake Houston Area flooded. Local leaders identified the disparity in release capacities between the Lake Conroe and Lake Houston Dams as one of the contributing factors to the severity of flooding. The floodgates on Lake Conroe can release water 15 times faster than the gates on Lake Houston. So, adding more floodgates to Lake Houston became one of the area’s primary mitigation goals.

New gates would let the City rapidly lower the water level of Lake Houston in advance of a storm to prevent or reduce upstream flooding.

gates for Lake Houston and Conroe — *Lake Houston (l) and Lake Conroe gates (r). Conroe release capacity is 15X greater.*

While the City of Houston initially obtained a $50 million grant from FEMA to add gates, two problems became apparent. The project cost more than anticipated and the benefits delivered did not justify the cost – at least the way FEMA was initially calculating them. However, a huge hurdle has been cleared.

The City of Houston has finally secured a favorable ruling from FEMA on a benefit-to-cost ratio, according to a press release from Mayor Pro Tem Dave Martin’s office on 12/7/2022. The key was the FEMA administrator’s decision to allow the inclusion of social benefits, for instance, avoidance of disruptions to business, commerce, schools and the area’s tax base. Those brought the BCR up to 2.88, according to Martin.

Hurdle Removed: Project Now Federally Compliant

Earlier this summer, Martin announced challenges related to the Lake Houston Spillway Dam Improvement Project. The City needed to secure a benefit to cost ratio (BCR) between .75 and 1 and had examined multiple alternatives to find a favorable balance between costs and benefits.

Martin, Mayor Sylvester Turner and Chief Recovery Officer Stephen Costello met with the Federal Emergency Management Agency (FEMA) Administrator to discuss the inequities of the Federal BCR formula associated with incorporation of social benefits.

As a result, Martin and Turner have announced that a large hurdle has been removed. The revised draft BCR for the Lake Houston Spillway Dam Improvement Project has been determined to be “federally compliant and is very favorable.”

The change affected the Lake Houston Gates and several other Houston stormwater projects including the massive, new Inwood Forest detention basin.

New BCR Based on Eleven Gates

Atkins, a City of Houston consultant, revised the BCR for an eleven-gate structure. The eleven gates will be built into the existing embankment on the east side of the Lake Houston Spillway Dam.

*New gates would be added to the earthen portion of dam in foreground, not spillway at far end as originally planned.*

Building the new gate structure in the east embankment removes the high construction risk of modifying the existing gate structure. It also allows continued use of the existing gate structure during construction, and eliminates the need for a coffer dam in the lake, according to Martin.

*The new gates would likely align with the original course of the San Jacinto River, the channel on the left.*

Cost Quadruples: Additional Funding Sources Now Necessary

The new preliminary cost estimate of $200 million exceeds the City’s original FEMA grant of $48 million.

Martin, Costello, and State Representative Dan Huberty have already met with the Texas House of Representatives Speaker Dade Phelan’s Director of Finance regarding additional funding. They have positioned the project as a “life and safety initiative” that affects the survival of the community and economy of the Lake Houston Area.

Martin has bi-partisan support already lined up for financing. Key partners this legislative session include:

Congressman Dan Crenshaw
State Senator Brandon Creighton
State Senator John Whitmire (who has already announced his intention to run for Houston mayor after Turner retires)
Speaker of the Texas House Dade Phelan
State Representative & Chair of Appropriations Dr. Greg Bonnen
State Representatives Charles Cunningham and Armando Walle.

Martin plans to work with Federal and State partners to ensure the cost of the Lake Houston Spillway Dam Project is fully funded before he leaves office in December 2023.

Said Martin, “Today a significant obstacle has been surpassed as this project moves forward through the financial process.” The new BCR should let federal, state, and local partners work toward fortifying the Lake Houston Area against future storms.

It would be unfair to call this a “start over.” A huge amount of engineering and analysis has gone into the project. However, challenges turned out to be greater than anyone anticipated after Harvey.

The original timetable from 12/16/19 showed the project completed by now. The fact that it is still alive is a tribute to the persistence of Martin, Turner, Costello and others.

Let’s look forward to the benefits, not backwards to the problems. People are working in the right direction. A huge obstacle has been eliminated. We just need to keep tackling new obstacles as they occur. Next step: the House and Senate.

I will post construction plans for the 11 gates and the Atkins’ BCR analysis as soon as the City supplies them; they promised they would.

Posted by Bob Rehak on 12/7/22

1926 Days since Hurricane Harvey