Your Chance to Ask Questions About the San Jacinto Watershed Master Drainage Plan

The San Jacinto Regional Watershed Master Drainage Plan (SJMDP) partners will host a virtual public meeting on August 13, 2020. The purpose: to provide information about study’s progress, and encourage public participation and input. 

Heat map in draft shows where most flood damage has occurred historically by sub-watershed.

Goals of Project

The SJMDP study began in April 2019 to identify flood mitigation projects that can be implemented in the near- and long-term. Their purpose: to reduce flood risks to people and property throughout the San Jacinto River watershed.

The study area includes nearly 3,000 square miles in seven different counties and approximately 535 miles of stream. Overall, the study aims to:

  • Provide an up-to-date technical basis to identify flooding vulnerabilities
  • Understand impacts of future growth
  • Improve flood resiliency within the watershed.

The SJMDP is scheduled for completion in fall 2020. 

Community engagement is an important component of the Harris County Bond Program. The partners want your participation as the program is implemented. 

Details of Virtual Meeting

The virtual community engagement meeting will be held on:

Thursday, August 13, 2020

6:30 p.m. to 7:30 p.m. 

Join online at PublicInput.com/SanJacMasterPlan 

Or by phone at 855-925-2801 with Meeting Code: 9742 

Note: HCFCD says that the “Join Online” link above will convert from a registration to a presentation link on the day of the webinar.

The meeting will begin with a brief presentation to share project updates, followed by a moderated Q&A session with Flood Control District team members.

Residents will be able to submit questions and comments throughout the presentation. Any comments not addressed during the Q&A session will receive a response after the event. 

For Those Who Cannot Attend…

The study partners will post a recorded version of the meeting on the Flood Control District’s website and YouTube channel after the event.

For questions, please contact the Flood Control District at 346-286-4152, or complete the online comment form.

You can also mail comments to:

  • Harris County Flood Control District
  • 9900 Northwest Freeway
  • Houston, Texas 77092
  • Attn: San Jacinto Regional Watershed Master Drainage Plan

For more information about the San Jacinto Regional Watershed Master Drainage Plan, visit www.sanjacstudy.org. 

For Those with Disabilities

Those with disabilities can make special meeting accommodations. If needed, please contact 346-286-4152 at least 48 hours prior to the meeting. 

Project Funding

The SJMDP is jointly funded with 75 percent from the Federal Emergency Management Agency (FEMA) Hazard Mitigation Planning Program and 25 percent from the four local partners: Harris County Flood Control, Montgomery County, City of Houston and the SJRA.

Posted by Bob Rehak on July 30, 2020

1037 Days after Hurricane Harvey

buyouts by SVI quartile

HCFCD Data Shows Socially Vulnerable Zip Codes Receive 80% of Buyouts

Harris County Judge Lina Hidalgo, Precinct 1 Commissioner Rodney Ellis, and Precinct 2 Commissioner Adrian Garcia are pushing the idea of a Community Resilience Task Force focused on helping socially vulnerable neighborhoods receive a higher percentage of the $2.5 billion flood bond.

However, zip codes that rank in the top 50% of the CDC’s Social Vulnerability Index (SVI) already receive 80% of Harris County Flood Control District buyouts and 79% of the District’s active mitigation projects.

FOIA Request Reveals Emphasis on SVI Index

Data obtained from HCFCD via the Freedom of Information Act shows that in Harris County…

…the two most socially vulnerable quartiles are FOUR TIMES more likely to receive a buyout.

HCFCD Buyouts Favor Socially Vulnerable Population 4:1

As of 7/28/2020. Source: Data obtained from HCFCD via FOIA request. Quartiles 3 and 4 are the most vulnerable on the CDC’s Social Vulnerability Index.

Here’s how that looks as a pie chart.

HCFCD Buyouts by SVI Quartile. The two most socially vulnerable quartiles receive 80% of all buyouts.

This is not surprising. For months, Hidalgo, Ellis and Garcia have pushed the District to incorporate the Social Vulnerability Index into its priorities. It has worked.

Do We Need More Balance?

Socially vulnerable neighborhoods get 80% of HCFCD buyouts and 79% of flood bond projects. Do those seem like fair percentages to you?

Tell the County Judge Your Opinion

The County Judge’s office is inviting the public to share their thoughts and ideas on the proposed draft bylaws of the Community Resilience Task Force that encourages even more spending by social vulnerability guidelines. 

You can register your opinion from now until July 30th, 2020, via one of the following methods:

  • Email CRTF@cjo.hctx.net and submit comments digitally, beginning July 21
  • Join a virtual focus group via Zoom. After registering, participants will receive a confirmation email containing information about joining the meeting.

For More Information

For more information on the “equity bias,” see this series on “Where Flood Mitigation Dollars Have Really Gone.” It was developed a year ago so the focus is on historical spending.

Or this series:

Posted by Bob Rehak on 7/29/2020

1065 Days since Hurricane Harvey

San Jacinto River Master Drainage Plan Draft Provides First Look at Final Report Due Out in August

On 7/23/2020, consultants for the San Jacinto River Basin Master Drainage Plan gave the SJRA Board and the public a first look at a draft of the plan. The final report is due out at the end of August. The draft shows the broad outline of the team’s efforts.

Draft Shows Broad Outline of Recommendations

It shows the types of recommendations they will make. However, this draft does not yet include specific recommendations as to prioritization of projects. Those will change before the final report. For instance, much of the draft focuses on upstream detention. But specific detention site recommendations have not yet been finalized.

Funding and Partners

Below are the key slides and a brief explanation of the main point behind each. This drainage study is 75% funded by a FEMA Hazard Mitigation Grant and 25% by four local partners: the SJRA, City of Houston, Harris County Flood Control, and Montgomery County.

Scope of Study

The study area covers almost 3,000 square miles and the tributaries listed on the left.
The SJRA primarily has responsibility for the portion of the watershed in Montgomery County. However, the scope of the drainage study extends to other counties including Waller, Grimes, Walker, Liberty, and San Jacinto.

Heat Map Shows Where Most Damage Occurs

The team started by looking at where flooding has occurred historically. The tan areas above show where the most damage has occurred.

Goals and Methodology

The partners started by looking at vulnerabilities and identifying mitigation possibilities. Their main goals are in red. The final report will make specific recommendations for detention, buy-outs and improving conveyance. Recommendations will also improve flood warning and communication.
The team started by integrating and updating all existing hydraulic and hydrologic models in the watershed as reflected on the latest 2018 lidar terrain data. They now take into account new construction, growth, additions to impervious cover, and Atlas-14 rainfall probabilities (which vary by sub-watershed within the larger watershed).
To calibrate and verify its H&H models, the drainage study team examined four historical storms that, together, impacted the entire study area. They then adjusted the models using radar rainfall data, and USGS high water marks and peak flow data. The objective: to make the models reflect “ground truth.”
The team is also looking at strategies to reduce sedimentation. However, this is not a major focus of this study. Their purpose is not to evaluate the relationship between sediment and flooding. Other studies will do that.

Three Main Areas of Focus

This slide shows the three major thrusts of drainage study effort over the last 1.5 years. The primary focus has been on: a) identifying the best locations for upstream detention that can reduce the volume of water coming downstream to populated areas during floods, b) where to install additional gages to improve flood predictions and warning times, and c) improving communication during emergencies.
This shows the steps the drainage team went through to evaluate and rank-order potential sites for detention.

Areas of Highest Potential for Mitigation

Here’s where they found the highest and lowest potential for mitigation. The box explains the watersheds that see the most effective solutions within the SJMDP study area, as explained in the list to the left of the slide.
Some drainage projects recommended in previous plans are no longer possible today because of upstream development. However, areas that once held potential for a single large project still hold potential for several smaller projects that add up to significant flood reduction.

Mitigation Project Funding

The cost all the drainage projects identified adds up to about $3 billion. They only reduce flooding of structures worth about $756 million dollars. Because costs exceed benefits, FEMA will not likely fund all of these.
However, many of the projects are in areas with low to moderate income (brown and tan areas). See the large concentration in the eastern watershed. That opens up other sources of funding, such as the Department of Housing and Urban Development where the benefit/cost ratio may not be as important.

Harmonizing Regulations Throughout Region

The team will also make recommendations to harmonize floodplain development regs throughout the region. Continuing to allow unmitigated upstream development in floodplains could destroy any new investment made to protect highly populated downstream areas.

Some Problems May Only Be Solved Through Buyouts

Buyouts usually have a high benefit-to-cost ratio relative to construction projects such as detention ponds. Buyout strategies can target the most vulnerable properties, such as those in the 2- and 5-year floodplains. None of the detention projects recommended by the team will likely remove those from danger.

Steps Still Not Completed

The team has finished the steps in red. They in the process of prioritizing projects and developing a phasing plan. The last bullet point is not part of this study.

More Upstream Gages Needed to Eliminate Blind Spots

The team has also identified locations for additional upstream gages and local partners who can help maintain those gages. Think of these like a “distant early warning” system. They give river forecasters visibility into “blind spots.” Forecasters will be able to add up the rainfall on various tributaries and predict the impact and timing of flooding downstream. That could give people more time to evacuate.

Ways to Improve Communication

The team is also looking at ways to communicate better during flood emergencies. They are looking at inundation mapping, evacuation routes, and improved communication protocols.

Timetable for Remainder of Project

This chart outlines the project workflow. It shows completed steps in red, and incomplete steps in yellow.
The final report with specific recommendations should be released at the end of August or in early September.

Every Little Bit Helps

I can’t wait to see this report in its final form. During the presentation, the presenter talked about reducing flooding downstream at the West Fork and I-45 by up to six feet if all upstream projects are implemented.

One thing to keep in mind: there is no single silver bullet that can solve the regions flood problems. All of these steps are additive. In my personal opinion, a foot here and a foot there can help offset future releases from Lake Conroe. People in the Lake Houston Area benefit from any and all upstream improvements.

Posted by Bob Rehak with thanks to SJRA and HCFCD

1064 Days since Hurricane Harvey and 313 since Imelda