smwi-logoThe San Marcos Watershed Initiative is a multi-year research and information gathering process with the end goal to create and implement a community-based and state/federally accepted Watershed Protection Plan (WPP) for the Upper San Marcos River. Click here for a project summary.

Vision Statement

A healthy watershed that supports a clean, clear, and flowing San Marcos River for the future as it was in the past.


Watershed Protection Plan

The Watershed Protection Plan is currently being drafted. Sections are available for review and comment as they are completed. Please click here for completed sections and additional information


Upper San Marcos Watershed – to download a high resolution version of the above map, click here (2MB PDF).

About the Upper San Marcos River & Aquifer Species Habitat Designation

In 2010, the Upper San Marcos River was cited on Texas Commission on Environmental Quality’s 303(d) list of impaired waterways, for exceeding total dissolved solids (TDS) water quality standards. The River is currently in compliance with the Clean Water Act Standards, but several pollutants have been identified as a concern.

The San Marcos Watershed Initiative (SMWI) began in 2012 as a multi-year process of research and information gathering with the end goal of implementing a community approved and federally accepted Watershed Protection Plan for the Upper San Marcos River. The Meadows Center for Water and the Environment and SMWI Stakeholders collected relevant data, identified potential sources of nonpoint source pollution and modeled water quality for existing and predicted future land use conditions. Because the Upper San Marcos River is spring fed and previously had exceptional water quality, stakeholders identified target levels that are more stringent than state standards and screening levels to protect the river.

Using this information, best management practices (BMPs) were selected to be implemented over time to preserve water quality throughout the watershed, including:

  • Structural BMPs for new development and retrofits for existing development
  • Demonstration projects to encourage water quality protection practices
  • Education and Outreach Strategies
  • Non Structural Management Measures including land management and preservation of undeveloped land
  • Enhancement and support for codes & regulations impacting water quality
  • Information gathering and monitoring to address data gaps

Efforts resulted in a comprehensive, voluntary and stakeholder-driven plan to manage surface water resources in the Upper San Marcos River watershed. The WPP addresses Total Dissolved Solids (TDS), E. coli, nutrients, sediment (TSS) and other pollutants associated with future growth and development and is expected to be accepted by TCEQ and US EPA in the Spring of 2017.

Implementing the WPP: Click here to read more.

Revised Critical Habitat Designation for Three Comal Springs Invertebrate Species [PDF]

See what the spring flows are doing:

USGS Gauge for the San Marcos River at University Drive

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smwatershedinitiative.org | smwatershed@txstate.edu

meadows-vertical-txstate-blue-goldThe Meadows Center for Water and the Environment
Texas State University
601 University Drive
San Marcos, TX 78666

The preparation of this website was financed through grants from the U.S. Environmental Protection Agency through the Texas Commission on Environmental Quality