Lavaca River Watershed Protection Plan A guidance document developed by the stakeholders of the Lavaca River watershed to address water quality in the Lavaca River Tidal (Assessment Units 1601_01, 1601_02, 1601_03), Lavaca River Above Tidal (1602_02, 1602_03), Big Brushy Creek (1602A_01), Rocky Creek (1602B_01, 1602B_02), and Lavaca River Above Campbell Branch (1602C_01, 1602C_02) April 2018 TWRI TR-507 Lavaca River Watershed Protection Plan A guidance document developed by the stakeholders of the Lavaca River watershed to address water quality in the Lavaca River Tidal (Assessment Units 1601_01, 1601_02, 1601_03), Lavaca River Above Tidal (1602_02, 1602_03), Big Brushy Creek (1602A_01), Rocky Creek (1602B_01, 1602B_02), and Lavaca River Above Campbell Branch (1602C_01, 1602C_02) Authored and prepared by: Michael Schramm, Allen Berthold, Clare Entwistle and Kirby Peddicord Texas Water Resources Institute Texas Water Resources Institute Technical Report – 507 April 2018 College Station, Texas Funding support for this project provided by the Texas Commission on Environmental Quality. Cover photo: Lavaca River in Hallettsville, TX, by Michael Schramm, TWRI Acknowledgments The Lavaca River Watershed Protection Plan (WPP) presents the strategy developed by stakeholders of the Lavaca River watershed to restore water quality. Stakeholders dedicated considerable time and effort in discussing the watershed, influences on water quality and potential methods to address water quality concerns, and selecting appropriate strate- gies to improve water quality. The ultimate success of the Lavaca River WPP achieving its goals depends heavily on the current and continued support from these individuals and agencies. Special appreciation is extended to the many watershed landowners and residents who attended the numerous meetings and events to provide direct input to the plan. The direct involvement of landowners and residents was critical to ensuring the plan included feasible management measures that address sources of water quality impairments in the watershed. The time and effort of landowners and residents are greatly appreciated and are reflected in the contents of this plan. Local and regional government agencies and organizations also played key roles in plan development. Representatives provided insight regarding their specific focus areas and ensured the inclusion of content in the plan that is appro- priate for the watershed. Local and regional agencies that contributed to the development of this WPP include: • City of Yoakum Public Works • City of Edna Public Works • Jackson and Lavaca counties • Jackson and Lavaca Soil and Water Conservation Districts • Lavaca-Navidad River Authority Agency support and input was an integral part of the WPP development process. In particular, the following agencies provided technical guidance and willingness to provide spe- cialized knowledge on a number of topics: • Texas A&M AgriLife Extension Service • Texas A&M AgriLife Research • Texas Commission on Environmental Quality • Texas Parks and Wildlife Department • Texas State Soil and Water Conservation Board • USDA Natural Resource Conservation Service i Lavaca River Watershed Protection Plan Table of Contents Acknowledgments .......................................................................................................................................i Table of Contents ........................................................................................................................................ii List of Figures ..............................................................................................................................................v List of Tables ...............................................................................................................................................vi List of Abbreviations .................................................................................................................................vii Executive Summary ................................................................................................................................... 1 Problem Statement ........................................................................................................................................................................ 1 Action Taken ...................................................................................................................................................................................... 2 Watershed Protection Plan Overview ...................................................................................................................................... 2 Pollutant Reductions .................................................................................................................................................................. 2 Recommended Actions ............................................................................................................................................................. 2 Education and Outreach ........................................................................................................................................................... 3 Tracking Progress and Measuring Success........................................................................................................................ 4 Goals of the Plan ......................................................................................................................................................................... 4 Chapter 1: Introduction to Watershed Management............................................................................. 5 Watersheds and Water Quality .............................................................................................................................................. 5 The Watershed Approach ........................................................................................................................................................ 6 Watershed Protection Plan ...................................................................................................................................................... 6 Adaptive Management ............................................................................................................................................................. 7 Education and Outreach ........................................................................................................................................................... 7 Chapter 2: Watershed Description ........................................................................................................... 8 Lavaca River and Watershed Description .......................................................................................................................... 8 Soils and Topography .............................................................................................................................................................10 Land Use and Land Management .......................................................................................................................................12 Climate ..........................................................................................................................................................................................12 Demographics ............................................................................................................................................................................13 Chapter 3: Water Quality ......................................................................................................................... 15 Bacteria ..........................................................................................................................................................................................17 RUAA ..........................................................................................................................................................................................19 Dissolved Oxygen......................................................................................................................................................................19 UAA .............................................................................................................................................................................................19 Nutrients .......................................................................................................................................................................................19 Flow ................................................................................................................................................................................................20 Potential Sources of Water Quality Issues .......................................................................................................................23 Domestic Livestock ...............................................................................................................................................................23 Wildlife and Feral Hogs .......................................................................................................................................................23 Domestic Pets .........................................................................................................................................................................23