Green infrastructure can clean up stormwater

Last month’s deluge was a good example of how rains hurt environment through germs, pollution

Last month, more than 2 million gallons of raw sewage overflowed across Houston, the result of Halloween weekend rains swamping the sewage system.

The sheer volume of stormwater transmitted by roads and parking lots into sewers overwhelmed the capacity of the system and sewage was released to nearby bayous and ultimately to Galveston Bay.

Unfortunately, this wasn’t an isolated incident — there are more than 40,000 sewer overflows every year in the United States. These events, along with other pollution picked up by stormwater, contribute to 80 percent of the major waterways in Greater Houston not being safe for swimming or fishing.

In addition to bacteria and pathogens, stormwater carries litter, heavy metals and construction debris into our waterways. In its 2015 Galveston Bay Report Card, the Galveston Bay Foundation gave the Bay a “D” for overall pollution and identified stormwater-carried litter and spilled motor oil as threats to its overall health.

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 fact, in 2012 the American Society of Civil Engineers assigned a grade of C- to Houston 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.

The city of Houston has already taken some steps to promote green infrastructure, like reducing its drainage fee for property owners who implement low impact development best practices. But more needs to be done to reduce pollution and trash in our waterways, reduce flooding and beautify the city. And we can look around the country for good models.

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.

Austin requires commercial properties to direct half of stormwater runoff to landscaped areas and is placing rain gardens in the middle of roads that double as trafficcalming devices.

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.

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”.

Over the past several months, the mayoral candidates have, rightfully so, talked a lot about the importance of improving Houston’s infrastructure. The next leader of Houston should deliver a bold vision to address sewage overflows, potentially deadly flooding and dangerous pathogens and litter in our waterways. Any truly comprehensive vision should prominently include green infrastructure as an affordable, effective and environmentally friendly way to keep the city safe, healthy and beautiful. Without a major commitment to solutions, as the city grows, so will the problem of stormwater.