June 3, 2025, the Sierra Club attended a meeting of the Double Bayou Watershed Partnership to hear about progress in the implementation of the Double Bayou Watershed Protection Plan (WPP). The Sierra Club has been involved with the creation of the Double Bayou WPP since the mid-2010s. The Plan was approved in 2016. The Double Bayou Watershed (DBW) has an East and West Fork and provides water for municipal, agricultural, commercial, and recreational uses.
Reasons to implement a WPP are to protect public health, prevent water quality from going below state standards, and treat pollution sources so that fishable and swimmable uses occur without undue harm to people and the environment. A WPP is a voluntary plan that a community puts together for a watershed or part of a watershed (a watershed includes all land and drainage that flows into a certain stream/river) for better water quality.
In the case of DBW, the concern is human disease-causing bacteria. The use of fecal indicator bacteria, which live with disease-causing bacteria, determines if public health is threatened. We found out at the meeting that in the DBW, indicator bacteria levels are 3 to 3.5 times the water quality standard. This has been determined via a water quality monitoring program which measures fecal indicator bacteria, nutrients, water flows, and other water quality indicators. This sampling is funded by theTexas State Soil and Water Conservation Board and has been extended through 2027.
The tidal segments of Double Bayou have had rising bacteria levels, although the rate of increase has slowed and sometimes stabilized recently. There is a lot of variability in bacteria levels seasonally and over the years.
During the meeting presentations we heard that about 46% of the bacteria comes from wildlife. It was revealed via questions that this figure includes feral hogs, which the State of Texas doesn’t consider to be wildlife. Therefore the probable impact of wildlife (mammals and birds – warm-blooded animals) is less than this figure. The DBWP is working with Texas A&M in an effort to tease out what percent of fecal indicator bacteria is related to wildlife and what is related to feral hogs.
Statistics also show that domestic animals are the source of 25% of the indicator bacteria. The West Fork has more domestic animal sources and the East Fork has more wildlife sources of fecal indicator bacteria. There is a small amount of fecal indicator bacteria from human sources (2%) but since this indicates sewage, possibly from leaking septic tanks, it’s impacts are greater and need additional investigation.
We also heard from the Wildlife Habitat Federation, which is an organization dedicated to restoration of natural habitats like native prairies and riparian and other wetlands. One speaker talked about “green infrastructure”, which includes forest restoration, prairie restoration, vegetated filter strips, and wetland restoration.
The Sierra Club intends to continue to monitor the DBWPP and water quality in Double Bayou so that all people, wildlife, and ecosystems have healthy streams and Galveston Bay waters to enjoy, value, and benefit from in the future.