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:
- San Jacinto
The City’s of Conroe and Houston also support the effort.
Sedimentation Known to Limit Floodway Conveyance
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.
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.
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.
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