Tag Archive for: Regional Sedimentation study

SJRA Board Accepts Grant Funding for Three Studies

Yesterday, the San Jacinto River Authority (SJRA) Board accepted three grants from the Texas Water Development Board (TWDB) to conduct studies for various projects. This was expected. The SJRA had applied for each of the grants about a year ago. The vote, however, now obligates the SJRA. It’s somewhat like applying for a loan and then signing the contract after it is approved.

Three Studies Now Teed Up

The SJRA and its partners can now officially start three studies:

  • An upper San Jacinto Watershed regional sedimentation study
  • A conceptual engineering feasibility study for flood-control dams in the Spring Creek Watershed
  • A joint reservoir operations study between Lake Conroe and Lake Houston
Lake Houston Gates can discharge only 10,000 CFS (left), while Lake Conroe’s can discharge 150,000 CFS. To help provide better watershed management, the Coastal Water Authority is studying the addition of 1000 crest gates to Lake Houston, necessitating the joint reservoir operations study.

Why Flood Mitigation Takes So Long

We are all learning together how long flood mitigation takes. It’s somewhat frustrating to see a conceptual engineering feasibility study being kicked off one month from the fourth anniversary of Hurricane Harvey.

I’m not pointing fingers at the SJRA, its partners, the TWDB, or the State. If you took the time to read all of the approximately 1500 posts on ReduceFlooding.com, you would see that:

  • Harvey happened right after the 2017 legislature finished its work.
  • Eighteen months elapsed before the legislature met again.
  • It took another nine months for the legislature and governor to approve flood mitigation funding.
  • Then, the TWDB needed to define rules for the distribution of funds, solicit public comment, refine the rules, solicit grant applications, and evaluate them in a competitive context.
  • Finally, add time for related preliminary studies such as the Lake Houston Spillway Improvement Project, the San Jacinto River Basin Master Drainage Study, a sand trap study, and a siting study for the flood-control dams.
  • And don’t forget the time to find partners and develop political consensus around solutions.

Still Years from Construction

The truly scary thing is that even when these studies are completed, we still could be years from construction and more years from completion of any of these projects.

For instance, we just started final engineering on the Lake Houston Spillway Improvement Project. Best-case projections show completion of the project in mid 2024 – 7 years after Harvey.

The system seems set up to protect money more than people. We certainly don’t want people rushing off, building half-baked projects that endanger people downstream, the environment, or the safety of a dam…especially if they produce no demonstrable benefit.

But we also don’t want people to flood multiple times waiting for flood-mitigation improvements. And some have. Remember Imelda? Just a thought as we head into the heart of hurricane season.

Studies Could Take 18 Months to 4 Years

The Spring Creek Flood-control Dam study will take 18 months. The Joint Reservoir Operations Study will take 3 years. And the Sediment Study is scheduled to take 4 years, though Matt Barrett, SJRA’s flood-mitigation director, is trying to compress that to 18 months.

If you missed the original post about these three studies, you can find more details here. SJRA partners in these projects include Harris County Flood Control, City of Houston, City of Humble, Montgomery County and five utility districts.

Posted by Bob Rehak on July 23, 2021

1424 Days since Hurricane Harvey and 673 since Imelda

SJRA to Consider Three Flood-Mitigation Studies Thursday

SJRA directors will consider accepting grant funding for three flood-mitigation studies at their board meeting on Thursday, 7/22/21. The studies include:

  • A joint reservoir operations study between Lake Conroe and Lake Houston
  • An upper San Jacinto Watershed regional sedimentation study
  • A conceptual engineering feasibility study for flood-control dams in the Spring Creek Watershed

The board will also consider executing escrow agreements related to each grant. TWDB grants work on a reimbursement basis. At the start of the project, TWDB puts the grant money into an escrow account. Then funds are drawn down as vendors submit invoices and TWDB approves them.

I posted previously about grant applications for these projects. Now that the grants have been approved, work can actually begin once the board agrees to accept the money. See details below about each project.

Joint Reservoir Operations Study

The addition of 1000-feet of crest gates to the Lake Houston Dam is a game changer for the way reservoirs on the San Jacinto work together. Right now, the gates on Lake Houston have a discharge capacity of only 10,000 cubic feet per second (CFS). The discharge capacity of the crest gates would increase that by more than 4X to 45,000 cfs. It’s still not the 150,000 CFS of Lake Conroe gates, but percentage-wise it’s much closer.

Thus, operators need to re-examine how best to synchronize their operations and plans. For instance, pre-releasing water in advance of a storm might be more viable now as a flood-mitigation strategy.

Another element of this study is a “flow forecasting tool.” It would predict rises in Lake Houston depending on the flow rates in tributaries during major storms. Matt Barrett, SJRA’s flood-mitigation director, says this tool could be useful for flood warnings and evacuations. If you knew that lake water would rise X feet in Y hours, and that your slab was a foot below X, you’d know exactly how much time you had to pack up your valuables and get out.

This study is being conducted with help from the Cities of Houston and Humble.

Upper San Jacinto Basin Sedimentation Study

The upper basin of the San Jacinto River includes everything above Lake Houston. This study has three goals:

  • Understand where the sediment is coming from
  • Learn where it ends up
  • Develop a management plan to handle it.

For the record, here is the scope of work. Note that stakeholder input and public meetings will be a big component of this project (Task 2). Tasks 3 and 6 include evaluation of sand mines. And Task 7 includes “Sand and Gravel Mining Best Management Practices.”

The San Jacinto West Fork has more than 20-square miles of sand mines in the 20-mile stretch between I-69 and I-45, exposing a swath of sediment averaging a mile wide.

The sedimentation study is being conducted with financial help from the Cities of Houston and Humble, and the Harris County Flood Control District.

A related sand-trap study is nearly complete. The SJRA should release it next month for public input.

Spring Creek Flood Control Dam Feasibility Study

About a year ago, SJRA applied for a TWDB grant to study the feasibility of building two flood control dams in the upper Spring Creek Watershed. The partners identified two preferred locations from a previous siting study that considered dozens. The two included Walnut and Birch Creek tributaries.

The objective now: to see whether the benefits justify the costs. Said another way, will the dams reduce flooding and protect enough structures to make the cost of building them worthwhile?

Together, they would have a combined capacity of 20,000 acre feet. That’s significant. But it would provide more benefit to people in the upper Spring Creek watershed than the Lake Houston Area.

The scope of work includes:

  • Environmental due diligence
  • Site investigations
  • Literature and mapping review
  • Permitting requirement investigations
  • Desktop surveys/assessments
  • Preliminary coordination with permitting agency
  • Conceptual design of dams to determine feasibility – geotechnical borings, alternative configurations development, H&H modeling analysis, etc.
  • Cost estimate development – dam construction costs, as well as costs related to land acquisition, utility conflicts and relocations, environmental mitigation, O&M, etc.
  • Update benefit/cost ratios (BCR) from SJRWMDP using data developed as part of this effort.

Partners in this effort include the SJRA, HCFCD, City of Humble, and five municipal utility districts. To learn more about these projects and others, consult pages 19 and 21 of this PDF.

To View or Participate in the Board Meeting

The SJRA board meeting starts at 8am.

If you choose to participate via webinar, register at this link and use webinar ID 950-202-179.

If you use the GoToWebinar App, you will have the opportunity to provide public comments.

To view the Agenda, visit SJRA’s website at: 07-22-21 Agenda and Coversheets.

Posted by Bob Rehak on 7/22/21

1423 Days after Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

TWDB Advances 4 of 5 SJRA Grant Applications for Flood Infrastructure Funding

The Texas Water Development Board (TWDB) has advanced four of five San Jacinto River Authority (SJRA) abridged grant applications to the next round for consideration. TWDB named them as priorities for the 2020 Flood Infrastructure Fund (FIF) cycle. That advances SJRA one step closer to funding for the projects. 

SJRA Now Invited to Submit Full Applications

With these rankings, SJRA will now submit full grant applications for four projects for approval. In the two-stage process, applicants first submit an abridged application. TWDB then prioritizes them within the overall available funding capacity. 

Senate Bill 7 last year made the Flood Infrastructure Fund (FIF) possible. Senator Brandon Creighton sponsored it. The Legislature passed it and Texas voters approved it through a constitutional amendment. FIF provides financial assistance in the form of loans and grants for flood control, flood mitigation, and drainage projects. 

Why SJRA Seeks Grants, Partnerships

As with most Texas river authorities, SJRA is not a taxing entity, therefore these large-scale flood mitigation projects require regional and local partnerships as well as grant funding.

“Hundreds of abridged applications were submitted by entities—cities, counties, other political subdivisions—as part of this competitive process. We are very proud SJRA was selected to move ahead in the approval process on four of our five abridged grant applications,” said Chuck Gilman, SJRA Director of Water Resources and Flood Management. “The next step is to find local partners who, along with SJRA, will commit to the local-match funding and in-kind services. These large-scale, impactful projects come with a very high price tag. It will take a regional approach with various funding commitments to see these projects through to completion. The FIF funding is an essential piece of that process.”

Flood Infrastructure Fund Criteria

According to Flood Infrastructure Fund criteria, eligible projects must fall under one of four categories:

  1. Flood Protection Planning for Watersheds
  2. Planning, Acquisition, and Design, Construction/Rehabilitation
  3. Federal Award Matching Funds
  4. Measures Immediately Effective in Protecting Life and Property

TWDB will review the full grant applications and make final selections for grant and loan funding later this year. 


Proposed Projects Advancing to Next Round

Upper San Jacinto River Basin Regional Sedimentation Study 

Would identify and create a plan for implementing potential sedimentation solutions in the Upper San Jacinto River Basin (Lake Houston watershed). It would evaluate the input, output, and storage of sediment for the entire basin as well as for sub-watersheds.  

LMI River Bend Sand Mine on San Jacinto West Fork exposes more than 500 acres of sand to floodwaters. Altogether, sand mines expose approximately 20 square miles of sand along the West Fork to floodwaters in a 20 mile stretch between I-45 and US59.
Spring Creek Watershed Flood Control Dams Conceptual Engineering Feasibility Study 

Would perform a conceptual engineering feasibility study of two potential dam/reservoir locations within the Spring Creek watershed. This is the next phase of the Spring Creek Siting Study, which is currently being completed as part of the San Jacinto Regional Watershed Master Drainage Plan. Harris County Flood Control District leads the Master Drainage Plan effort. SJRA and other regional partners support it.

Lake Conroe – Lake Houston Joint Reservoir Operations Study 

Would develop a joint reservoir operations and communications strategy for Lake Conroe and Lake Houston. 
The City of Houston is currently studying new tainter gates for the Lake Houston dam. They could greatly increase the controlled release capacity. 

The main goal of the plan: to determine the most efficient and safe operation of the two reservoirs in series. The study would evaluate multiple individual components of a joint operational strategy. 

It will evaluate:

  • Operational synergy between the two reservoirs
  • Joint notification and communications protocols
  • Pre-release
  • Impacts on water supply
  • Use of forecasting tools.

This project will benefit both water supply and flood mitigation in the region.

Flood Early Warning System for San Jacinto County 

Would provide for installation of rain and river/stream gages at three locations identified as critical by San Jacinto County to provide early warning information to the county during storm events.  


  • Winters Bayou at State Highway 150
  • East Fork San Jacinto River at FM 945
  • Peach Creek at FM 3081. 

Rain and river/stream stage data obtained at the sites would be transmitted to SJRA’s ALERT2 network and displayed on SJRA’s Contrail system. The data could be viewed online via SJRA’s website. That lets San Jacinto County staff and residents view the data at any time.

Not Advancing to Next Round

The SJRA had also submitted a first-round grant application to develop preliminary designs for sand traps. The sand traps were supposed to reduce the amount of sediment moving downstream. SJRA confirmed that this grant application will not move forward.

Posted by Bob Rehak on 9/24/2020 based on input from SJRA

1122 Days since Hurricane Harvey

Details of SJRA Grant Application for Upper River Basin Sedimentation Study

SJRA has applied for a $375,000 grant from the Texas Water Development Board’s (TWDB) Flood Infrastructure Fund to study sedimentation in a six county area:

  • Liberty
  • Waller
  • Grimes
  • San Jacinto
  • Harris
  • Montgomery

The City’s of Conroe and Houston also support the effort.

Sedimentation Known to Limit Floodway Conveyance

Sedimentation in the Upper San Jacinto River Basin says the SJRA, “…is known to impact floodway conveyance capacity.”

SJRA Grant Application

In order to create a plan for implementing potential sediment solutions, this study will develop “sediment budgets” by evaluating the input, output, and storage of sediment for the entire basin, as well as for sub-watersheds within the basin.

Identifying Largest Problem Areas

This process will identify which sub-watersheds in the basin:

  • Produce the most sediment
  • Store the most sediment.

With this information, the SJRA says it can prioritize locations for improvements, mitigate loss of floodway conveyance, and develop best management practices. In regard to the latter, changes of regulations could be considered.

Much Has Changed Since Last Study

KBR conducted the last study on this issue in 1998. Since then, we’ve seen exponential growth of sand mining and development in this watershed. Both have the capacity to change conclusions from the KBR study. So a new study is highly warranted.

Confluence of Spring Creek and West Fork. TCEQ alleges that Liberty Mines discharged 56 million gallons of white waste water into the West Fork.

What’s Included in Study?

Specific tasks anticipated to be included in the scope of work include, but are not necessarily limited to:

  • Upper San Jacinto River Basin watershed characterization
  • Inventory of available existing data
  • Annual sediment output determination
  • Annual sediment storage determination
  • Sediment transport modeling
  • Individual sediment source or storage locations determination
  • Individual site investigations
  • Key stakeholder and permitting agency coordination
  • Development of conceptual solutions and overall implementation strategy
  • Development of Upper San Jacinto River Basin sediment management plan

If approved, the grant would also include development of cost estimates, preliminary exhibits, and preliminary permitting requirement evaluation.

All identified projects, efforts, and practices will be ranked and included in an implementation plan. Ultimately all information will be compiled into a regional sediment management plan, which can guide mitigation efforts in the future.

Building on Other Recent Efforts

The project will take advantage of data and tools developed recently as part of the San Jacinto Regional Watershed Master Drainage Plan project (SJRWMDP) now nearing completion.

Harris County Flood Control District (HCFCD) leads that project. It utilizes Atlas 14 rainfall. The project will also utilize data developed by the U.S. Army Corps of Engineers (USACE) and Harris County while dredging sediment from the mouth of Lake Houston.

SJRA feels the proposed project will increase benefits gained from state and federal dredging efforts which total approximately $125 million.

Finally, this project will also build on a sand trap development project currently being performed by SJRA in coordination with HCFCD along the West and East Forks of the San Jacinto River. SJRA already submitted a separate abridged application for the next phase of the sand trap development project.

FOUR YEARS to Complete!@#$%

SJRA anticipates that this study will take 4 years to complete! It says the work will only take 18 months or less, but budgeting uncertainties related to COVID-19 will delay the start of the project. With seven partners, the matching funds demanded from each would only about to about $50,000.

However, this delay, says the SJRA, will allow completion of the sand trap preliminary design study so that the SJRA can use that information as input for the sedimentation study.

While this grant application covers only planning and study, it will identify sedimentation solutions, and guide future sedimentation reduction projects, efforts, and practices.

Helping Preserve Water Storage Capacity in Lake Houston

Any sedimentation reduction activity in the Upper San Jacinto River Basin (Lake Houston watershed) should reduce the sediment load entering Lake Houston. That would help preserve volume for water storage. Lake Houston is the main water supply reservoir for approximately 2 million people.

Until SJRA identifies sedimentation solutions, it cannot quantify sedimentation reduction benefits. One of the main goals, however, would be to restore, maintain, or expand storm flow capacity, which could potentially remove structures from the floodplain.

Flood mitigation provided by these future projects/efforts/practices could benefit areas impacted by Hurricane Harvey and Tropical Storm Imelda as well as other major storms such as Hurricanes Ike and Rita, and storms in 1994, 1998, 2015, and 2016.

To review the full application, click here.

To review related applications submitted by SJRA to TWDB, click the Reports page and scroll to the bottom of the SJRA tab.

Four Years Is WAAAAY Too Long

The only thing I don’t like about this study is the three year delay due to COVID. It’s already been three years since Harvey.

Of five recent grants that SJRA applied for, this is the only one that mentions such a delay.

If six counties, the Cities of Conroe and Houston, and the SJRA can’t come up with $50,000 each in matching funds, something’s seriously wrong. It would take more than that to repair ONE flooded home in each of those municipalities and counties. And that makes me wonder whether hidden hands are intentionally delaying this important study.

West Fork Sand Mine cited by TCEQ for unauthorized discharge of 56 million gallons of sediment-laden waste water into West Fork San Jacinto.

If you get in a helicopter and fly around for a day, it’s pretty obvious where the problems are.

Posted by Bob Rehak on 7/11/2020

1047 Days after Hurricane Harvey

Details of Four SJRA Grant Applications for TWDB Flood Infrastructure Funds

Yesterday, I ran an article about Texas Water Development Board (TWDB) Flood-Infrastructure-Fund Grant Applications. It incorrectly stated that the City of Houston had applied for six flood infrastructure fund grants. However, five of those listed were actually submitted by other entities, such as the San Jacinto River Authority (SJRA). Below is more information about those grant applications.

Elm Grove Project Correctly Attributed to City

The City did apply for a grant to fund construction of a detention basin on the Perry Homes’ Woodridge Village Property north of Elm Grove Village in Kingwood. It was correctly attributed.

Four Projects Should Have Been Attributed to SJRA

The SJRA submitted four of the five applications that were incorrectly attributed.

  1. San Jacinto River Sand Trap Development
  2. Spring Creek Watershed Flood Control Dams Conceptual Engineering
  3. Upper San Jacinto River Basin Regional Sedimentation Study
  4. Lake Conroe-Lake Houston Joint Reservoir Operations Study

Mayor Pro Tem and District E Council Member Dave Martin personally supported those projects, hence the confusion. TWDB rules for Flood Infrastructure Fund Grants place a premium on support by all affected governmental entities within a watershed. Those include cities, counties, MUDs, river authorities, townships, etc.

Details of SJRA Grant Applications

Here’s more information about those four proposals.

  1. The Sand Trap Study currently underway has to do with identifying acceptable locations for the sand traps. Once identified, the new grant would cover the cost of their detailed design. The proposed study would extend work currently underway.
  2. The Spring Creek Watershed Flood Control Dams Conceptual Engineering Grant would cover the cost of partially designing dams. The San Jacinto River Basin Study identified locations for the dams. But it did not look at construction details. The new study would look at things, such as environmental impacts, utility conflicts, height of embankments, size of reservoir, etc. It continues work to date in the Spring Creek Watershed. San Jacinto River Basin Study partners have not yet released the locations.
  3. The Regional Sedimentation study builds on KBR’s work in 2000. KBR studied portions of the watershed that drain into Lake Houston, but not the East Fork, Caney Creek and Peach Creek. The new study has two objectives: understand where sediment is coming from and what can be done to reduce it. For instance, if the sediment is coming from new developments or sand mines, there may be a need to look at regulations that affect those.
  4. The Lake Conroe-Lake Houston Joint Reservoir Operations Study would look at the best ways to operate the two dams under different storm scenarios. It would assume the construction of additional floodgates on Lake Houston. It would also model storms approaching from different directions. The study will answer questions, such as “What would the effect of pre-releasing water into Galveston Bay be on Cities such as Baytown if a hurricane approaches from the south?” The deliverable: an operations plan.

Sedimentation and Its Role in Flooding

Two large sources of sediment: sand mines and new developments. Here the drainage for the Artavia development tries to find a path to the West Fork, through or around two sand mines. One of the mines was cited by the TCEQ for discharging 56-million gallons of sediment-laden wastewater into the West Fork.
The City, County, State and Federal Government are still working to remove the West Fork Mouth Bar, 1040 days after Hurricane Harvey. This bar is partially the result of excess sedimentation. During Harvey, this bar formed a partial dam that contributed to the flooding of more than 4000 homes and businesses.

More East Fork Gages in San Jacinto County

In addition, the SJRA has applied for a grant to purchase several more stream gages in San Jacinto County. San Jacinto County lies between Cleveland and Lake Livingston.

San Jacinto County partnered with the SJRA on that grant and would provide ongoing maintenance and operations if the application is successful.

Benefits of Additional Gages

Those additional gages would extend the flood-warning time for people in the East Fork Watershed. Such information is crucial for developing evacuation plans in emergencies.

The gages would also help inform the gate operations at Lake Houston. During Imelda, the East Fork received ten times more rain than the West Fork, but the West Fork has far more gages. That hindered understanding of where the danger was coming from and when it would strike.

As news becomes available about other grant applications in the San Jacinto Watershed, I will post it here.

Posted by Bob Rehak on 7/4/2020

1040 Days after Hurricane Harvey