2025 Technical Reports

Authors: Audrey McCrary, Janelle Wright, Ward Ling

This project targeted several watersheds with existing total maximum daily load implementation plans (I-Plans) or watershed protection plans (WPPs) within the Texas Coastal Zone, including: Tres Palacios Creek, Lavaca River, Arroyo Colorado, Lower Nueces River, Bastrop Bayou, Cedar Bayou, Double Bayou, and San Bernard River watersheds. These watersheds are typified by rural communities with small population centers.

Each WPP identified a need to implement management measures to tackle the bacterial and nutrient loadings from stormwater runoff in their area. In addition to common stormwater concerns (household waste, pet waste, etc.), reduction of bacteria via on-site sewage facilities (OSSFs or “septic systems”) improvements was a common goal. In the Texas Coastal Zone, it is extremely important to properly maintain and not allow untreated waste to travel through the permeable soil to sensitive waterbodies and coastlines nearby. To this end, poorly maintained and failing OSSFs became an additional target for the proposed project.

Authors: Duncan Kikoyo, Lucas Gregory, Saboor Rahmany, Tina Hendon, Janelle Wright, Aabha Khanal

Routine water quality monitoring indicates that several waterbodies in the Proctor Lake watershed (Duncan Creek, Rush-Copperas Creek, Sabana River, Sweetwater Creek, and Leon River below Leon Reservoir) do not meet water quality standards for recreation use because of elevated concentrations of bacteria. Leon River below Leon Reservoir is also considered impaired for aquatic life use due to depressed dissolved oxygen concentrations. Several use concerns due to depressed dissolved oxygen, elevated concentrations of chlorophyll-a, bacteria, and nitrates also exist in the watershed. With water quality impairments comes a need to plan and implement actions that restore water quality and ensure safe and healthy water.

To meet this need, the Texas Water Resources Institute, in partnership with the Texas State Soil and Water Conservation Board, is working with local stakeholders to characterize the watershed by identifying sources of pollution in the watershed contributing to water quality impairments and related concerns.

This report describes the analysis of existing data and information on water quality impairments and pollutant loading in the watershed. Existing data and information are used to the extent possible to characterize water quality conditions, watershed characteristics, and potential sources of pollution contributing to water quality impairments and concerns.

Authors: Luna Yang, Tina Hendon, Ward Ling, Sarah Stannard, Kate Watson, and Lucas Gregory

This document presents a plan to restore and protect water quality in the Middle Yegua Creek watershed. By approaching water quality issues within a drainage area rather than political boundaries, this plan holistically identifies potential pollutant sources and solutions. This approach also incorporates the values, visions, and knowledge of individuals with a direct stake in the water quality conditions of the creek.

Water quality monitoring indicates that segments of the Middle Yegua Creek do not meet water quality standards for primary contact recreation use because of elevated levels of Escherichia coli (E. coli) in the 2022 Texas Integrated Report of Surface Water Quality for the Clean Water Act Sections 305(b) and 303(d). Because of these water quality impairments, there was a need to plan and implement measures that restore water quality and ensure safe and healthy water for stakeholders. To meet this need, an assessment and planning project was undertaken to develop the Middle Yegua Creek
Watershed Protection Plan (WPP).