Lake Granbury
Watershed Protection Plan
Hood County is experiencing rapid growth occurring in areas that do not have a centralized
sewage collection system. The majority of the established and some new developments are
relying on septic systems in close proximity to the lake.
A substantial portion of this development around the lake is located
on man-made canals and coves which provide very little water interaction with the reservoir's
main body. Additionally soil conditions in much of the area are not suitable for on-site
septic systems and many on-site systems around the lake include absorption fields that do
not provide capacity to adequately treat sewage.
Lake Granbury is experiencing elevated concentrations of E. coli
bacteria in these coves and canals that are impairing state water quality standards for
contact recreational use such as swimming or water skiing. E. coli is a bacteria normally
found in the intestines of humans and other warm-blooded animals. EPA studies have shown
E. coli is a good indicator of fecal contamination of water and the presence of pathogens
which can cause intestinal illnesses and gastroenteritis. One study done by Dufour (1984)
demonstrated a direct relationship between the rate of gastroenteritis among swimmers and
the concentrations of E. coli in freshwater. Frequent sources of E. coli can include sewage
overflows, polluted storm water runoff and malfunctioning septic systems.
For the last several years, regular water quality testing has found elevated concentrations
of E. Coli in the coves of Lake Granbury resulting in water quality to exceed criteria set
for contact recreation use. A substantial portion of the developed area around Lake Granbury,
which lies wholly within Hood County, consists of unincorporated subdivisions that do not have
sewage collection systems and centralized sewage treatment facilities.
Approximately 9,000 septic tanks are located around Lake Granbury with
absorption fields installed on small lots in close proximity to the lake. Most of the
inhabited areas around the lake exist on man-made coves. These coves are shallow, dead-end
bodies of water with little mixing or interaction with the main body of the reservoir. New
development in the areas without collection and treatment systems rely on individual on-site
septic tanks and absorption fields.
The Lake Granbury Watershed Protection Plan Project is funded by federal grant dollars
provided to the Texas Commission on Environmental Quality (TCEQ) by the United States
Environmental Protection Agency (EPA). The TCEQ has contracted with the Brazos River Authority
to develop a Watershed Protection Plan (WPP). This project will provide an assessment of existing
and potential water quality threats from on-going nonpoint source (NPS) pollution within the
Lake Granbury watershed. The project will also provide a WPP to improve and protect water
quality within Lake Granbury.
Information obtained from this project will provide federal, state and
local decision makers with a variety of mechanisms that can be employed to promote the orderly
restoration of the lakes aquatic environment and to prevent additional degradation.
- Identify causes and sources of pollution affecting the lake's coves and canals;
- Identify management strategies based on sources of pollution;
- Estimate the load reductions expected to be achieved through management strategies;
- Estimate the amounts and sources of technical and financial assistance needed to implement management strategies;
- Develop an implementation schedule; and
- Develop a set of criteria that can be used to determine whether loading reductions are being achieved and
that over time substantial progress is being made toward meeting the WPP goals.
A Stakeholder Advisory Group has been set up to establish project communication among stakeholders.
Specific tasks that will be undertaken by the stakeholders group include: identification of areas
with the greatest concerns; making recommendations for additional monitoring; and making
recommendations on BMPs. Meetings will be held to enhance and support participation of stakeholders
(including the general public and other interested parties), enhance public understanding of the
project, and encourage early and continued participation in selecting, designing, and implementing
management measures.
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