Hurricane Harvey brought record rainfall to the Houston-Galveston region and the Texas coast. After making landfall near Rockport, Texas as a Category 4 storm on August 25, 2017 and lingering for more than four days, Harvey dropped more than 50 inches of rain in parts of Houston, leaving behind a devastated region.
On a Houston Canoe Club outing on Double Bayou, a scenic two-fork stream on the eastern side of Galveston Bay, participants “watched reflections from the water’s surface as they danced on overhanging oak branches.”
For a typical recreational visitor from Houston, close to the city but seemingly far removed, this picturesque rural setting might not conjure thoughts of a problem like water pollution. But Double Bayou’s West Fork has been officially listed by state environmental officials as “impaired” since 2004, with bacteria levels that are considered too high and oxygen levels that are too low.
Excess bacteria can pose risks for people who contact the water. Too little oxygen can threaten aquatic life.
The East Fork of Double Bayou, while not officially classified as “impaired” like the West Fork, is still officially listed as a waterway of “concern” for both bacteria and oxygen readings.
To help mitigate those problems, HARC is partnering with the Texas State and Soil Water Conservation Board (TSSWCB), U.S. Geological Survey and Shead Conservation Solutions in a collaborative, multi-year project to work with stakeholders in developing a Double Bayou Watershed Protection Plan.
“If bacteria levels in Double Bayou are too high, there is a potential for illness, and this can impact not only public health but also the local economy,” said Stephanie Glenn, a senior research scientist at HARC and manager of the Double Bayou project.
“The Watershed Protection Planning process has brought the stakeholders together to talk about implementing voluntary measures to mitigate elevated bacteria levels in Double Bayou,” she added.
One important example of the collaborative nature of the cleanup project for Double Bayou involves a computer-modeling effort to estimate potential amounts and locations of possible bacterial sources. They include livestock (such as cattle, horses and goats), wildlife (such as deer) and feral hogs, wastewater treatment plants and septic systems.
The computer model was developed at Texas A&M University and is called SELECT (for Spatially Explicit Load Enrichment Calculation Tool). It uses data assembled from a wide range of government sources – for example, statistics about wastewater treatment plants, agriculture, wildlife, soils and land uses.
“The SELECT model spatially characterizes potential bacteria loads within a watershed,” Glenn explained. “Stakeholder contributions for identifying potential sources are crucial in developing accurate inputs to the model. Stakeholder meetings are held to discuss the amounts and locations of potential sources, and to review the model outputs.”
Three stakeholder workgroups were convened to focus on possible categories of sources for bacteria entering the bayou – one addressing agriculture, wildlife and feral hogs, one for recreation and hunting, and one for wastewater facilities and systems.
These workgroups helped researchers tap stakeholders’ knowledge and insights to help insure that the modeling results would be an accurate simulation of real-world conditions. Based on their close familiarity with the Double Bayou watershed, members did things like improving population estimates for livestock and wildlife and estimating failure rates for septic systems.
With funds provided through the TSSWCB and EPA, the Watershed Protection Plan process began in 2012. The plan’s blueprint for improving the bayou’s water quality is expected to be finished in 2016, setting the stage for possible implementation if subsequent funding is available. More information is available at the partnership’s website, www.doublebayou.org.