Details of Proposed Lake Houston-Lake Conroe Reservoir Joint Operations Grant

On June 15, the SJRA submitted an abridged application to the Texas Water Development Board (TWDB). The SJRA wants to develop a joint operations plan for Lake Houston and Lake Conroe reservoirs. The grant assumes that FEMA approves construction of additional gates for Lake Houston after completion of preliminary engineering in the second half of next year. The addition of gates could potentially make a pre-release strategy for Lake Houston more viable and that could be a game changer for operations of both dams.

*If the floodgates on the Lake Houston spillway are upgraded to discharge as much water as Lake Conroe’s, there will be a definite need to rethink how these two dissimilar dams can work together.*

About the TWDB Application Process

The TWDB website explains the application process and eligibility requirements for grants from the Flood Infrastructure Fund. State Senator Brandon Creighton’s SB7 made the Flood Infrastructure Fund possible in 2019.

The Flood Infrastructure Fund applications are a two-step process: Abridged Applications provide the TWDB with information needed to prioritize projects. Applicants whose projects rank within the program’s available capacity are invited to submit full financial-assistance applications at a later date. Those provide more detailed financial, legal, engineering, and other information. Once the full review process is complete, the TWDB will consider project funding.

The two stage process ensures:

Projects meet criteria before applicants invest the vast majority of their time and effort
TWDB has enough money to fund the most worthy projects

It’s much like getting a commitment letter from a bank before you fill out a full mortgage application.

Why Joint Operations Plan Needed

Widespread flooding in the Lake Houston Area during Hurricane Harvey underscored the need for a joint operations plan with Lake Conroe. Many downstream residents reported they thought the flood threat had passed. Then the SJRA opened its flood gates and started releasing up to 79,000 cubic feet per second. By itself, that would have been the 9th largest flood in West Fork history.

Those who flooded question the timing and volume of the release, and whether a pre-release strategy could have reduced downstream damage.

Once additional gates are in place at Lake Houston, says the SJRA in its application, a joint operations plan will benefit both water supply and flood mitigation.

Objective of Plan

The main goal of the plan is to determine:

The most efficient and safe operation of the two reservoirs…
… in series …
… by evaluating multiple individual components of operational strategy.

Components of Joint Plan

Informing Future Protocol for Lake Houston Gates

SJRA suggests that information and strategies developed as part of this effort could impact the development of CWA’s operating protocol for the future Lake Houston gates.

Joint Notification Protocol Development

The river authority also says that it is important that both reservoir operators develop joint notification protocols and public communication strategies. These must be consistent with the requirements of House Bill 26 passed during the 86th Texas Legislative Session. During Harvey, many downstream residents claim they received no warning of the SJRA release or the need to evacuate.

Forecasting Tools

Another major part of the grant covers forecasting tools. SJRA is currently developing a reservoir forecasting tool for Lake Conroe, funded partially via a grant from TWDB. It will predict lake levels and release rates from the Lake Conroe dam based on:

Weather forecasts
Observed rainfall
Lake levels
Other data.

A similar tool for Lake Houston could help synchronize forecasting for both reservoirs including the entire Lake Houston watershed (approximately 3,000 square miles). This could provide scientific data that governs pre-release at either reservoir and operations at Lake Houston.

Average Monthly Household Income in Project Scoring

Much of the application discusses demographics of the watershed. The TWDB scoring process gives preference to rural and low-to-moderate income areas. References to AMHI refer to Average Monthly Household Income. Unfortunately (for grant purposes), the AMHI for this watershed is 164% of the state average.

That limits the maximum amount of a grant to 50% of the project cost. A social vulnerability index also acts as a tie breaker.

Next Steps in Application Process

The TWDB is currently screening and prioritizing abridged applications for projects.
Before the end of the summer, TWDB will invite extended applications for the high priority projects.
Extended applications are due this Fall.
TWDB will begin making financial commitments this winter.

For the full text of the abridged grant application, click here.

Posted by Bob Rehak on 7/7/2020

1043 Days after Hurricane Harvey