In late November, more than 630,000 gallons of raw sewage overflowed across Dallas, the result of record-setting rainfall over the weekend.
The sheer volume of stormwater transmitted by roads and parking lots into sewers overwhelmed the capacity of the system and sewage was released across five Dallas locations.
Unfortunately, this wasn't an isolated incident. More than 2 million gallons of raw sewage overflowed across Houston, the result of Halloween weekend rains swamping the sewage system. And in late May, 250,000 gallons of wastewater flowed through East Austin after severe flooding.
In addition to bacteria and pathogens, stormwater carries litter, heavy metals and construction debris into our creeks, bayous, lakes and into our rivers, ultimately ending up in Galveston Bay. In fact, stormwater pollution is a major reason the state has designated the DFW stretch of the Trinity as unsafe for basic uses such as swimming or fishing.
Dirty water and garbage not only blight scenic waterways, but can make people sick. Swimmers exposed to this pollution can suffer a range of waterborne illnesses including stomach flu, skin rashes and other serious health problems. For senior citizens, small children and people with weak immune systems, the results can be fatal.
Our existing water infrastructure is not up to the task of dealing with these threats. In 2012, the American Society of Civil Engineers assigned a grade of D to Texas for flood control and drainage infrastructure.
Texas has natural ways to control stormwater — when it rains, water can soak into fields and forests. But, as the state grows, more and more of these fields and forests are replaced with hard surfaces like rooftops, parking lots and highways. Rain runs down these surfaces, picks up animal waste, pesticides, motor oil and trash and sends this pollution down storm drains and ultimately into creeks, lakes and bays.
The best way to protect Texans from this pollution is to prevent it. A key solution is mimicking natural techniques for absorbing rain through smarter, greener infrastructure, like porous pavement, green roofs, parks, roadside plantings and rain barrels.
Green infrastructure stops rain where it falls, storing it or letting it filter back into the ground naturally. This keeps it from running off dirty streets and carrying pollution to our waterways while also helping reduce flooding.
And we can look around the country for good models on how to make that happen.
Seattle has a plan to reduce stormwater runoff by 50 percent from downtown by 2030 and offers generous rebates for homes and businesses to harvest rainwater.
Ann Arbor, Mich., requires new or rebuilt roads be "green streets," using vegetation and engineering strategies to allow stormwater to soak into the soil, get filtered and then leave the street at a greatly reduced volume.
Los Angeles has set a goal to achieve zero trash to the Los Angeles River by 2016 by installing trash capture devices on storm drains, enhancing enforcement of litter laws and increasing street sweeping.
Here in Texas, we’ve seen some cities take the initial steps to curb stormwater pollution, mitigate flooding and protect public health and our environment.
The City of Houston has taken some steps to promote green infrastructure, like reducing its drainage fee for property owners who increase pervious cover, install porous pavement, or do other low impact development best practices.
Austin requires commercial properties direct half of stormwater runoff to landscaped areas and is placing rain gardens in the middle of roads that double as traffic-calming devices.
And, in 2013, the North Central Texas Council of Governments released a plan to clean up pollution in the Trinity, including recommendations for DFW-area cities to adopt green infrastructure standards for development in their comprehensive plans and to eliminate any prohibitions on cisterns, rain barrels or permeable pavement.
These program don't just help the environment and public safety, but also make fiscal sense. A study by the U.S. Environmental Protection Agency found lower total costs for 11 of 12 green infrastructure projects when compared to equivalent "grey" infrastructure projects, leading them to recommend its use to the "maximum extent possible".
As we search for ways to accommodate major population growth across the state, work to protect our communities from water pollution and flooding and beautify our cities, green infrastructure ought to remain among the top of our list as an effective and affordable solution.
Sara E. Smith is the staff attorney for Environment Texas, a statewide nonpartisan nonprofit advocating for clean air, clean water and open spaces.