Update on Harris County Flood Mitigation Efforts

Today, at a meeting of the Harris County Flood Resilience Task Force, Vanessa Toro of the County Judge’s Office and Leah Chambers, Principal of consulting firm Outside Voices presented several slides about flooding and flood-mitigation efforts in Harris County that you might find interesting. Their presentation started with a series of slides that illuminated the history of flooding in Harris County; types of flooding; mitigation challenges, and mitigation efforts currently underway.

Historical Flooding and Mitigation

The first four slides address historical flooding and build on each other.

Different Types of Flooding Throughout County

The presentation then went into examples of the different types of flooding we experience. While river and bayou flooding are important to the Lake Houston Area, in other parts of the county, street flooding is a bigger issue. During high intensity rainfalls, water can’t get to the bayous.

Down in the southern part of the county, coastal flooding from storm surge is the main concern.

Each type of flooding requires different mitigation strategies.

For instance:

• Flood professionals often address river- and bayou-flooding with detention ponds and channel widening.
• Street flooding may require better maintenance of ditches, bigger storm drains and wider storm sewers.
• Coastal flooding may require dikes and better building codes that elevate homes higher.

Key Challenges with Flood Mitigation

The presentation then segued into key challenges we face and how the county is trying to address them.

The first slide in this section discussed incomplete knowledge.

For instance, FEMA’s flood maps measure river, bayou, major channel and coastal flooding, but not street flooding, which is a major problem in the inner city. Hopefully, the next generation of flood maps (See MAAPNext) will help address that.

There’s a feeling that large scale infrastructure projects by themselves will not solve our flooding problems. Various groups within the county are looking at ways to supplement them. The engineer’s office is looking at subdivision drainage. Several other groups are collaborating to explore nature based solutions, flood proofing, and more.

The title of the slide above refers to difficulty of coordinating flood-control efforts across complex jurisdictional boundaries.

Different areas have different priorities, needs and timetables. No one understands that better than those who live near county lines. For instance, upstream counties often use lax regulation and enforcement as a way to entice developers – much to the detriment of those who live downstream.

Flood Resilience Efforts Now Underway

While the 2018 flood bond gets all the publicity, it’s certainly not the only Harris County effort underway to mitigate flooding. The slide below shows the variety of efforts.

They include:

• The Community Flood Resilience Task Force, a group designed to give voice to communities in developing the next generation of flood mitigation efforts.
• MAAPNext to update flood maps, incorporate the more data sources, and make flood-risk easier to understand.
• Resilience Actions Inventory, an ongoing effort to catalog resilience initiatives, projects and programs throughout the county.
• Infrastructure Resilience Team – an interdepartmental team planning resilience projects. It includes: Flood Control, Engineering, Community Services, Public Health, Emergency Management, and the Toll Road Authority.
• New departments, such as the Office of Sustainability and the Deputy County Administrator for Resilience and Infrastructure.
• Structural efforts that fall under the:
  • 2018 Flood Bond
  • The Flood Resilience Trust established recently.
  • The ongoing Capital Improvement and Maintenance budgets of HCFCD.

All these efforts may not mesh like the gears in a Swiss watch. At least not today. But it’s good to know that efforts are underway on more than one front.

For a high-resolution PDF of the PowerPoint, click here.

Posted by Bob Rehak on 9/25/2021 based on information from the Harris County Judge’s Office

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