A Sustainability-Driven, Zoning Approach to Flood Mitigation by Woodley Burrow

Floods and Zoning in Houston, Texas

My hometown, Houston, is the preeminent non-zoning city of America. While most other large cities have adopted zoning ordinances, Houston cherishes its anti-zoning policy as an achievement. Even in the wake of Hurricane Harvey, a time in which Houston leaders were considering all flood preparation strategies, Mayor Sylvester Turner dismissed zoning: “Zoning wouldn’t have changed anything. We would have been a city with zoning that flooded.”[1] I think Mayor Turner is giving up too fast.

Every year, the United States loses lives and communities to storms like Irma, Sandy, and Harvey. I would challenge Mayor Turner, or any coastal community leader, to make flood resilience a core component of city design. Local leaders should implement zoning policies that ensure flood-resilient infrastructure within susceptible areas.

Why should We address Hurricanes and Flooding?

Before discussing my recommended course of action, I will outline why hurricanes are an issue that we must prioritize.

First, Hurricanes are extraordinarily costly. Hurricane Katrina cost around $161 billion. Hurricane Sandy inflicted an estimated $70 billion in damages.[2] Hurricane Harvey had a total cost of around $125 billion.[3] Devastating storms cause severe economic losses.

Second, storms contribute to air and water pollution. Floods typically carry nonpoint source pollutants, like pesticides, fertilizers, plastic grocery bags, and sediments. These pollutants contribute to ocean dead zones, or areas with low oxygen.[4] These dead zones are unsafe for aquatic life. Flooding in industrialized regions risks additional pollution. A report by the Environmental Integrity Project discusses the impact of Hurricane Harvey on air and water pollution. Power outages and equipment malfunctions caused by Harvey resulted in the release of 2.2 million pounds of air pollution over 48 hours in the Houston area.[5] Similarly, the report details the release of over 150 million gallons of wastewater during the storm, a figure that may even underestimate the total amount.[6]

Third, hurricanes perpetuate and expose environmental injustice. Hurricane Katrina demonstrated this trend. In New Orleans, a collection of white neighborhoods, coined the “White Teapot,” were positioned at a relatively high elevation and they did not flood. Meanwhile, nearby predominantly black neighborhoods suffered from unprecedented flooding. As the black neighborhoods flooded, they endured floodwaters that contained oil, chemicals, and fecal bacteria.[7] Inadequate federal assistance further compounded these equity issues. FEMA refused to provide benefits to individuals who shared housing during the storm. FEMA also refused to rebuild rental housing or aid owners of non-insured vehicles.[8] These recovery practices left behind the poorest communities, the communities that needed aid the most.

A comprehensive flood mitigation strategy, focused around city-planning, could help resolve these three critical issues.

Zoning Strategies for Coastal Communities

Zoning allows the local government to determine the use of a parcel of land. [9] Zoning also allows local governments to apply regulations and enact infrastructure initiatives in specified areas. Governments can use zoning to encourage green infrastructure development in the middle of urbanized cities. For example, zoning can limit the width of roads or require native vegetation on a residential site.[10] Both of these regulations would reduce flood risk. In a similar vein, zoning can protect larger-scale greenspace development. Greenspaces, or public areas that predominantly contain vegetation, absorb rainwater and have a large impact on flood mitigation. The city of Milwaukee, for example, plans to create approximately 143 new acres of greenspace by 2030. The city claims this program will reduce flooding by half an inch of rainwater per storm.[11] This type of proactive strategy combined with zoning could work for many communities.

Zoning ordinances can also guide development by placing regulations on buildings. Norfolk, Virginia has included clever provisions in their recently updated zoning ordinance. To keep flooding mitigation at the forefront of development, Norfolk’s zoning ordinance now requires each development project to meet a resilience quotient. Developments are awarded points for how well they achieve flood risk reduction, stormwater management, and energy resilience.[12] Developments that do not reach the point threshold must pass through further scrutiny. Finally, Norfolk applies different regulations to different zones. For projects within the 500-year floodplain, developers are required to elevate buildings at least 1.5 feet above the 500-year flood level. Meanwhile, areas safely outside of floodplains do not have to meet these stricter regulations.[13]

To resolve equity issues, I think we can look to New York City’s zoning for coastal resiliency initiative. New York aims to provide flexibility to buildings inside of the 500-year floodplain because they expect more intense flooding events in the future. A recently proposed zoning policy would allow New York to lift reconstruction regulations during times of crisis. During a flood recovery, the process of obtaining New York Department of Buildings permits would become greatly simplified within the flood zone.[14] This expedited process would help the city reach and work with all of its citizens in an efficient manner.

I think the initiatives taken by Milwaukee, Norfolk, and New York are initiatives that would reap immediate and long-term benefits for coastal communities. Flood mitigation must be baked into city design, or else we will continue to see extreme losses and costs. To summarize my zoning action plan:

  1. Include green infrastructure and greenspaces as part of zoning plan.
  2. Impose regulations that encourage flood-resilient practices within 500-year flood plains.
  3. Alleviate burdens related to reconstruction process.


[1] Henry Grabar, “Don’t Blame Houston’s Lax Zoning for Harvey’s Destruction,” Slate, Aug 31, 2017, accessed June 23, 2020, https://slate.com/business/2017/08/how-houston-and-harris-countys-zoning-approach-affected-hurricane-harvey-flooding.html.

[2] Sarah Gibbens, “Hurricane Sandy, explained,” National Geographic, Feb 11, 2019, accessed June 23, 2020, https://www.nationalgeographic.com/environment/natural-disasters/reference/hurricane-sandy/.

[3] National Oceanic and Atmospheric Administration, Hurricane Costs, June 18, 2020, accessed June 23, 2020, https://coast.noaa.gov/states/fast-facts/hurricane-costs.html.

[4] National Oceanic and Atmospheric Administration, Watersheds, flooding, and pollution, accessed June 23, 2020, https://www.noaa.gov/education/resource-collections/freshwater/watersheds-flooding-and-pollution.

[5] Environmental Integrity Project, Preparing for the Next Storm, August 16, 2018, accessed June 22, 2020, https://environmentalintegrity.org/wp-content/uploads/2018/08/Hurricane-Harvey-Report-Final.pdf.

[6] Ibid.

[7] Reilly Morse, “Environmental Justice through the Eye of Hurricane Katrina,” Joint Center for Political and Economic Studies, 2008, accessed June 22, 2020, https://inequality.stanford.edu/sites/default/files/media/_media/pdf/key_issues/Environment_policy.pdf.

[8] Ibid.

[9] Benjamin Schneider, “CityLab University: Zoning Codes,” Bloomberg CityLab, Aug 6, 2019, accessed June 22, 2020, https://www.bloomberg.com/news/articles/2019-08-06/how-to-understand-municipal-zoning-codes.

[10] Pioneer Valley Planning Commission, Green Infrastructure In Zoning, accessed June 23, 2020, http://www.pvpc.org/sites/default/files/files/PVPC-Green%20Infrastructure%20and%20Zoning.pdf.

[11] City of Milwaukee Environmental Collaboration Office, The City of Milwaukee Green Infrastructure Plan, June 2019, accessed June 22, 2020, https://city.milwaukee.gov/ImageLibrary/WCC/Images/GreenLots/FINALGIPLAN–reduced_2.pdf.

[12] Pew Charitable Trusts, Norfolk’s Revised Zoning Ordinance Aims to Improve Flood Resilience, November 19, 2019, accessed June 22, 2020, https://www.pewtrusts.org/en/research-and-analysis/issue-briefs/2019/11/norfolks-revised-zoning-ordinance-aims-to-improve-flood-resilience.

[13] Ibid.

[14] NYC Department of City Planning, Zoning for Coastal Flood Resiliency, May 2019, accessed June 22, 2020, www.nyc.gov/zcfr.

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