Hurricane HarveyFlooding from Hurricane Harvey causes a host of public health concerns

By Neil S. Grigg

Published 31 August 2017

Houston’s drinking water system is being stressed by overflowing water reservoirs and dams, breached levees and possible problems at treatment plants and in the water distribution system. Failure of drinking water systems could lead to water shortages. Raw sewage, dead bodies in the water and release of dangerous chemicals into the floodwaters could lead to the spread of disease through contact with contaminated water and to infection through open wounds. Houston has at least a dozen sites that have been designated environmentally hazardous, so there is a risk of petrochemical contamination. Indeed, companies have reported that pollutants from refineries have already been released. As if those are not bad enough, the “unprecedented” amount of water leads to the perfect breeding opportunities for mosquitoes, which are vectors of Zika and many other infectious diseases.

The historic rainfall dumped by Hurricane Harvey has already led to deaths by drownings and the destruction of many homes.

Houston’s drinking water system is being stressed by overflowing water reservoirs and dams, breached levees and possible problems at treatment plants and in the water distribution system. Failure of drinking water systems could lead to water shortages.

As a civil engineer who has studied how flooding affects water systems, I also see a number of public health concerns. Raw sewage, dead bodies in the water and release of dangerous chemicals into the floodwaters could lead to the spread of disease through contact with contaminated water and to infection through open wounds.

And because Houston has at least a dozen sites that have been designated environmentally hazardous, there is a risk of petrochemical contamination. Indeed, companies have reported that pollutants from refineries have already been released.

As if those are not bad enough, the “unprecedented” amount of water leads to the perfect breeding opportunities for mosquitoes, which are vectors of Zika and many other infectious diseases.

Flood response systems
Flood impacts hit hardest on the most vulnerable and exposed people, especially children, the elderly and disabled, and the poor.

In Houston, several authorities are involved in flood mitigation and rescue efforts, beginning with city government, which handles street runoff and storm drains as well as emergency response. The Harris County Flood Control District, which was organized in response to devastating Houston-area floods in 1929 and 1925, has a regional flood control program. It works with the U.S. Army Corps of Engineers, which operates local reservoirs that were built in the 1940s to prevent flooding.

The National Guard and the Federal Emergency Management Agency also are helping, along with local shelters and community members.

Toxic soup
The scenes of rescues during and immediately after the storms from Harvey may suggest that relief has arrived, but these images hide the aftermath of disease and misery. This includes the risk of contamination from floodwaters from many unsavory sources, beginning with raw sewage from failing sewer pipes. Other sources of bacteria and disease agents are landfills, septic tanks, medical wastes, feedlots, cemeteries and portable toilets.

This toxic soup can lead to a host of infectious diseases, diarrhea and wound infections, among other medical problems, when bacteria and parasitic organisms in floodwaters penetrate the body.