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Surface Water Quality Monitoring to Support Implementation of the Plum Creek Watershed Protection Plan


Problem/Need Statement

Plum Creek rises in Hays County north of Kyle and runs south through Caldwell County, passing Lockhart and Luling, and eventually joins the San Marcos River at their confluence north of Gonzales County. Plum Creek is 52 miles in length and has a drainage area of 389 mi2. According to the 2014 Texas Water Quality Inventory and 303(d) List, Plum Creek (Segment 1810) is impaired by elevated bacteria concentrations (category 4b) and exhibits nutrient enrichment concerns for ammonia, nitrate+nitrite nitrogen and total phosphorus.

TSSWCB and AgriLife Extension established the Plum Creek Watershed Partnership (PCWP) in April 2006. The PCWP Steering Committee completed the “Plum Creek Watershed Protection Plan” in February 2008. Information about the PCWP is available at Sources of pollutants identified in the Plum Creek WPP include urban storm water runoff, pet waste, failing or inadequate on-site sewage facilities (septic systems), wastewater treatment facilities, livestock, wildlife, invasive species (feral hogs), and oil and gas production.

Through TSSWCB projects 03-19, Surface Water Quality Monitoring to Support Plum Creek Watershed Protection Plan Development, and 10-07, Surface Water Quality Monitoring and Additional Data Collection Activities to Support the Implementation of the Plum Creek Watershed Protection Plan, and project 14-11 of the same name. GBRA collected water quality data to fill data gaps. During these projects, sampling of water quality data was severely hampered by drought that covered the watershed, causing the tributaries to run dry and the springs to slow to almost negligible flow.

Facilitated by a local watershed coordinator, implementation of the Plum Creek WPP is currently underway. TSSWCB projects provide technical and financial assistance through the local SWCDs to agricultural producers in developing and implementing water quality management plans (WQMPs). In order to reduce feral hog impacts on the stream, education and technical assistance is being provided by AgriLife Extension to landowners in the watershed on strategies to reduce and manage feral hog populations.

General Project Description

Through this project, GBRA will continue to collect surface water quality monitoring (SWQM) data to characterize the Plum Creek watershed, including the contributing wastewater effluents. Monitoring data will be used to assess and evaluate the effectiveness of the BMPs that have been or will be implemented in the watershed as a result of the Plum Creek WPP. The sampling regime will include diurnal, spring flow, and targeted monitoring under more elevated and typical base flow conditions over 9 months in 2017. This will provide a more complete and representative data set to characterize the Plum Creek watershed and document water quality improvements.

GBRA will conduct the work performed under this project including technical and financial supervision, preparation of status reports, and coordination with local stakeholders, surface water quality monitoring sample collection and analysis, and data management. GBRA will participate in the PCWP in order to communicate project goals, activities and accomplishments to affected parties. GBRA will continue to host and maintain an Internet webpage for the dissemination of information. GBRA’s Public Communication and Education staff will present information on Plum Creek, nonpoint source pollution and environmental education to schools in the watershed as well as at other environmental outreach opportunities.

GBRA will develop a Quality Assurance Project Plan (QAPP) for monitoring activities to ensure data of known and acceptable quality are generated in this project. The QAPP will be consistent with EPA Requirements for Quality Assurance Project Plans (QA/R-5), the TSSWCB Environmental Data Quality Management Plan, and TCEQ Surface Water Quality Monitoring Procedures, Volume 1: Physical and Chemical Monitoring Methods, 2012 (RG-415) and Surface Water Quality Monitoring Procedures, Volume 2: Methods for Collecting and Analyzing Biological Assemblage and Habitat Data, 2014(RG-416). GBRA will submit monitoring data to TCEQ for inclusion in the TCEQ Surface Water Quality Monitoring Information System (SWQMIS).

Total Costs: $126,535

Workplan: 17-58

QAPP: 17-58

"Protecting and Enhancing Natural Resources since 1939."

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