Lessons from Hurricane Harvey

Posted by on Aug 30, 2017

Hurricane Harvey on August 25, 2017. Composite satellite image: NASA

When my wife and I were in Houston several years ago—I believe for a green building conference—I was surprised to discover that a modest afternoon rainstorm, which had dumped perhaps an inch of rain, flooded the streets with five or six inches of water. The water didn’t impede drivers too much—I suppose they were used to it—but that vehicles left wakes was a bit disconcerting.

I was reminded of that minor flooding as I’ve followed the devastation occurring in Houston and the surrounding region this week. It is a massive storm: the first Category 4 hurricane to strike the Texas Gulf Coast since 1967. The massive volume of rainfall dumped on a broad swath of Texas, including Corpus Christie and Houston, has already exceeded 50 inches in some areas (the most ever by a storm in the Continental U.S.), and it’s still raining!

While the casualties so far total about 30, that number is likely to rise—as it did with Hurricane Katrina in New Orleans—in the coming days and weeks. As of Tuesday morning, 300,000 homes were without power; seven coastal counties in Texas and Louisiana have issued mandatory evacuation orders; dozens of emergency shelters are filling up; and eight rivers are at or near record flood levels.

This historical photo shows flooding of downtown Houston in December, 1935. Flooding has been a recurring problem in this region. Photo: J.R. Gonzales

Adding to the risks in Houston are aging flood-control levees and floodwater impoundments that rely earthen dams. If one of those impoundments above Houston were to catastrophically fail, a very bad situation could become far worse very quickly.

Like Superstorm Sandy in 2012 and Hurricane Katrina five years earlier, Hurricane Harvey provides important lessons that will no-doubt influence planning and design for years to come. It will also provide lasting inspiration for the heroic and selfless efforts by thousands of emergency response personnel and volunteers to rescue residents trapped in their flooded homes and vehicles.

Relative to the widespread flooding, one issue that has been brought up a lot this week is the fact that Houston, a city with over 2.3 million residents, doesn’t have zoning—and that lack of regulation may have contributed to the flooding. According to a New York Times article on August 29th, there was a 24% increase in impervious surface in Houston in the 15 years from 1996 to 2011. Without zoning laws, coordinated infrastructure planning is difficult.

Rainfall from Hurricane Harvey in the Houston area as of August 29, 2017. Image: New York Times

Given these realities, I offer the following specific recommendations—not only for Houston, but for any city that is vulnerable to natural disasters:

  1. Invest in resiliency planning

Understanding a region’s vulnerabilities and planning for them should be a top priority for any city today. Fortunately, resiliency planning is gaining traction. The 100 Resilient Cities Program of the Rockefeller Foundation has done a great deal to encourage that by funding chief resiliency officers in cities worldwide—though only 23 U.S. cities were included in that program. Houston is the largest U.S. city that did not receive funding for a chief resiliency officer from the Rockefeller Foundation, and I am not aware that the City has addressed resiliency planning in any way.

Resiliency planning is partly about where to build, but it’s also about ensuring that state-of-the-art knowledge is used in updating building codes and other municipal regulations. Houston desperately needs such planning.

  1. Avoid flood-prone building sites

While Houston is located some distance from the Gulf Coast and the downtown sits about 50 feet above sea level, it is a very flat city, which makes drainage very difficult. Flooding has been a recurrent problem over the City’s history. Fortunately, Houston isn’t directly affected by storm surges—as occurred with Hurricane Katrina in New Orleans—but storms surges at the Gulf Coast do slow the flow of waterways that carry stormwater runoff away from Houston and surrounding areas.

The lesson of where we build is a complicated one. Houston began its dramatic population growth after the Great Galveston Hurricane of 1900—to date the worst natural disaster in U.S. history with 6,000 to 12,000 fatalities. Located away from the Gulf Coast, Houston was a much safer place than Galveston. So Texans had the right idea to expand there rather than Galveston, but successfully developing a swampy, flat area requires well-designed stormwater infrastructure, and Houston doesn’t have that.

  1. Elevate buildings and equipment

Hurricane Harvey won’t be the last flooding event to strike the Houston region. The City should immediately impose strict requirements for elevating living spaces in new buildings. Thorough analysis should be made, in the coming months, of the depth of flooding that has occurred with Harvey, and reasonable first floor heights above the base flood elevation (BFE) should be mandated. I’m guessing that a reasonable requirement would be BFE+5 (five feet above the base flood elevation), which is well above current FEMA recommendations, but that decision should be based on what is learned about the current flooding.

Within buildings, there should be building code requirements to raise mechanical and electrical equipment to provide reasonable flood protection. Roof-mounting of air conditioners, heat pumps, and other mechanical equipment probably makes sense, but at a minimum that equipment should be elevated above the first floor level. Electrical panels should similarly be elevated.

  1. Build with wettable materials

When flooding occurs, damage can be greatly reduced if the materials that get wet are able to dry out without suffering permanent damage. In regions prone to flooding, such as the Gulf Coast of Texas, building codes should mandate the use of wettable materials. Paper-faced drywall, wood or laminate floors, and wall-to-wall carpeting do not belong in such buildings—or at least not on the lower floors of such buildings.

  1. Provide for passive survivability

Passive survivability is the idea that buildings should be designed and built to maintain habitable conditions in the event of an extended power outage or interruption in heating fuel. This is achieved with such features as a highly insulated building envelope, cooling-load avoidance strategies, natural ventilation, and passive solar design. In locations that are vulnerable to natural disasters, such as Houston, ensuring passive survivability is a high enough priority that it should be incorporated into building codes.

Final thoughts

There will be a lot of talk over the coming months about the Houston area bouncing back. I’d rather see the City and region bounce forward. We can end up with something better in the renovation and rebuilding that occurs in the aftermath of this disaster. Tens of billions of dollars of federal funds will be spent rebuilding in this chronically flood-prone region of South Texas. That rebuilding should be done in a way that not only reduces vulnerability to future damage, but also saves energy, increases comfort, and protects residents from all sorts of disturbances and interruptions.

These lessons don’t just apply to Houston and that region, but in most of the United States. Other cities should be paying close attention and learning from happening in Texas (and now Louisiana) this week.

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Along with founding the Resilient Design Institute in 2012, Alex is founder of BuildingGreen, Inc. To keep up with his latest articles and musings, you can sign up for his Twitter feed. To receive e-mail notices of new blogs, sign up at the top of the page.

9 Comments

  1. Great piece, Alex, that I hope gets widely circulated to Houston decisionmakers, as well as federal, state and local decisionmakers involved in designing, funding, engineering and constructing anti-fragile localities.

  2. Spot on article. We never learn and continue to build on flood plains right next to levees. Complete insanity to have the nations oil refineries in a flood zone. The Army Corps of Engineers knows better but they are weak and will not fight politics. The only way I would live there is to build floating structures similar to the Cajun homes now being built in bayou country. God bless the victims and the rescuers.

  3. Well said! I stumbled upon your website some time ago and signed up for the blog immediately! It sounds like we have similar mindsets as we are working hard everyday to show builders and folks in general a better way to build. We would sure like to meet you sometime.

  4. We visited Florida last winter and were surprised to see such building considerations being taken into account, even for coastal state park structures such as bath-houses. It’s a visible, and realistic, response to changing and anticipated water events.

  5. Thank you for this forward thinking article. I’ve shared it with people in my coastal city. We haven’t had much hurricane threats on the west coast, but flooding from winter rainstorms are real here.

    Earlier this year, I’ve read “The Great Derangement: Climate Change and the Unthinkable” by Amitav Ghosh and found his observations and analysis to be thought provoking. Have you read this?

    • Chie, I haven’t read The Great Derangement. I should do that. Hope you are well.

  6. Great article voicing considerations for best building practices in many parts of the country. The New England Hurricane of 1938 along with hurricanes Sandy and Irene remind us that other coastal areas are not immune. I have a meeting set with my local town administrator to learn what our disaster plan is.

  7. Alex, Thanks for these guidelines without it sounding like an admonition. No city could have handled this amount of rainfall, yet if this is to be a new normal, then we know we need to listen. Houston did apply for the Rockefeller Foundation’s 100 Resilient Cities Program (I think they applied in two of the three rounds)and Houston was not accepted. I’m curious to know why given our history of issues.
    There has been some planning. The city appointed a Flood Czar in April 2016. Also, there are ongoing discussions about how to deal with storm surge – either build a dike/River Thames style gate in the ship channel or greatly increase coastal wetlands for a buffer.

    • Thanks Tom for this information. I’m glad to hear that Houston has a Flood Czar. I agree that expecting stormwater infrastructure to fully handle 40-plus inches of rain is unrealistic.

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