Res 2019-063/Interlocal Agreement with Texas State University for Watershed Protection Plan funding; providing for the reimbursement by Texas State University to the City of San Marcos in the sum of $35,000 for the development of best management practice

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26. Background Inforination: The Upper San Marcos River segment (Segment 1814) is 4.5 miles long and extends from Spring Lake to its confluence with the Blanco River. The River is primarily spring -fed and receives periodic inputs of stormflow from four major tributaries. This segment of the river is classified for contact recreation, exceptional aquatic life use, drinking water supply for downstream users, and is home to five federally listed endangered species. The City of San Marcos and Texas State University have seen unprecedented growth over the past decade. Growth in the watershed and the surrounding area is rapidly changing land use, putting pressure on surface water quality and groundwater resources. Sampling data show that water quality in Spring Lake and the Upper San Marcos River decline after storm flow events, especially with regard to total suspended solids (TSS) and nutrients. Elevated levels of bacteria in the river and its tributaries are also associated with stormflow. In 2010, the Upper San Marcos River was cited on TCEQ's 303(d) list of impaired waterways for exceeding TDS water quality standards. Several other pollutants have also been identified as a concern by stakeholders in the watershed. Because the Upper San Marcos River is spring -fed and has exceptional water quality, stakeholders identified target levels that are more stringent than the state standards and screening levels in order to protect the river. These water quality targets are part of the Upper San Marcos River WPP. The WPP, known locally as the San Marcos Watershed Initiative (SMWI), addresses TDS, E. coli, nutrients, sediment, and other pollutants associated with future growth and development. This WPP is unique in that it was developed in coordination with several other significant watershed -level water quality protection efforts, including a regional Habitat Conservation Plan, City- and University -led Water Quality Protection Plan, City -led Comprehensive Watershed Master Plan and City and University MS4 permitting process. The SMWI Stakeholders worked together to weave these efforts into a holistic management plan to restore and protect water quality in the Upper San Marcos River, complete with long term technical implementation schedules, coordinated educational efforts, and funding strategies. These interwoven initiatives will ensure funding and support for implementation of the WPP. Stakeholders selected a suite of structural and non-structural BMPs to mitigate current and future potential water quality impairments in the watershed. A subset of these BMPs was prioritized for immediate implementation, while others will be implemented over a number of years, as required to mitigate nonpoint source pollution from future development and other activities in the watershed. 27. General Project Description: The 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 WPP for the Upper San Marcos River. The Meadows Center for Water and the Environment and SMWI stakeholders compiled and collected relevant data, identified potential sources of nonpoint source pollution and modeled water quality for existing and predicted future land use conditions. This information was used to prioritize potential locations for implementing selected BMPs over time to preserve water quality (TDS, TSS, nutrients and bacteria) throughout the watershed including: 0 Structural BMPs for new developments and retrofits for existing development (Task 3) 0 Demonstration projects to encourage adoption of water quality protection practices (Task 3) 0 Education and Outreach Strategies (Task 4) 0 Analysis and improvement of Codes & Regulations impacting water quality (Task 5) 0 Information gathering to address remaining data gaps (Task 6) The SMWI stakeholders selected a suite of BMPs to mitigate future potential water quality impairments in the watershed, a subset of these BMPs was prioritized for immediate implementation. The first Implementation Phase will include functional demonstration projects/BMPs, education and outreach activities, review of water quality protection ordinances, and coordination of water quality monitoring activities. These efforts will lead to a modest reduction in NPS pollution (and likely a corresponding improvement in instream concentrations of pollutants) but, more importantly, they will serve as demonstrations, pilots, and educational resources to ensure that the WPP is fully implemented in the coming years. The Stakeholder Committee will play an active role in education and outreach, as well as in determining if the WPP implementation is successful, through the tracking of milestones and objectives. BMPs installed during Implementation Phase I will serve as demonstrations highlighting the effectiveness of BMPs to water resource managers, community leaders, developers, and citizens. Demonstrations will include preventative, stormwater, and LID measures, and will provide critical cost and pollution reduction information to the City and University regarding future implementation of additional Page n of 27