2018 Technical Reports

Authors: M. Schramm, T. Broad, T. Arsuffi

Trends in Escherichia coli (E. coli) and dissolved oxygen (DO) at Upper Llano watershed water quality monitoring stations were evaluated for calendar years 2001-2016. E. coli concentrations and loads were evaluated with linear regressions and Weighted Regressions on Time, Discharge, and Season (WRTDS). DO concentrations were evaluated with linear regression and generalized additive mixed models (GAMMs). WRTDS and GAMMs were also used to remove effects of year to year variations of flow on E. coli and annual variations in mean temperature on dissolved oxygen. Linear regression indicated a statistically significant decrease in E. coli concentrations on the main stem of the Llano River immediately downstream of the the North and South Llano River confluence. Linear regression did not indicate statistically significant changes in DO concentrations at any sites in the the watershed. From 2001 through 2016 total E. coli loads decreased by 3.99 × 10⁴ million colonies per day on the North Llano and 1.34 × 10⁷ million colonies per day on the Llano River. Flow-normalized loads decreased by 1.27 × 10⁵ million colonies per day and 5.87 × 10⁶ million colonies per day on the North Llano and Llano rivers respectively. Estimated E. coli load reductions appear substantial; however, the estimations are considerably biased which decreases the certainty that estimated load reductions are indeed real. Despite uncertainty, it is reasonable to infer that land use practices and changes in the watershed have not contributed to increases in flow-normalized E. coli loads between 2001-2016. GAMMs estimate that mean DO concentrations decreased 8.8% on the North Llano and 8% on the Llano during the same time period. Despite the decrease, mean DO concentration remain well within state water quality standards for aquatic life established for the watershed. The GAMMs, as designed in this analysis, are only used only to substantiate underlying trends in DO concentration. Because covariates that are characteristic of eutrophication are not included in this analysis, the GAMMs do not provide causal inference into mechanisms behind the observed responses in DO. If future research is warranted, additional instream monitoring and experimentation would be required to quantify possible eutrophic responses to changes in nutrients and chlorophyll-a.

Authors: T. Broad, T. Arsuffi, M. Schramm

The Upper Llano River (North and South Llano rivers) is currently a healthy ecosystem supporting a variety of aquatic and terrestrial ecosystems, as well as numerous recreational opportunities. However, a number of threats to this critical resource do exist. To address these threats, local stakeholders, through the Upper Llano River Watershed Coordination Committee developed a watershed protection plan (WPP). A WPP for the Upper Llano River above Junction was completed in early 2016 and received final acceptance from the Environmental Protection Agency (EPA) in October, 2016. A full-time watershed coordinator position was considered critical in initiating and carrying out the implementation process by the watershed coordination committee. The watershed coordinator has provided technical assistance to stakeholders, acquired additional funding for implementation strategies, coordinated outreach and education efforts, and monitored water quality data to identify if implementation efforts have been successful. Over the last two years the watershed coordinator has requested over $4 million and has received over $2 million in program funds for implementation efforts in the Upper Llano WPP. Education and Outreach efforts over the last two years included more than 30 workshops, field days, and presentations. Watershed curricula created as part of the WPP implementation through the Llano River Field Station Outdoor School was delivered to 64 Independent School Districts across the region.

Authors: Nikki Dictson, Auburn University, Texas Riparian Association; Clare Entwistle, Texas Water Resources Institute, Texas Riparian Association; Nathan Glavy, Destiny Russell, Texas Water Resources Institute; Hughes Simpson, Texas A&M Forest Service

The State of Texas has more than 191,000 miles of rivers and streams that comprise corridors of great economic, social, cultural, and environmental value. Riparian degradation is a major threat to water quality, in-stream habitat, terrestrial wildlife, aquatic species, and overall stream health. The Texas Riparian and Stream Ecosystem Education Program is funded by the U.S. Environmental Protection Agency (EPA) through the Texas State Soil and Water Conservation Board (TSSWCB). The Texas Water Resources Institute (TWRI) coordinated and partnered with the Texas A&M AgriLife Extension Service, Texas A&M AgriLife Research, TSSWCB, EPA, Texas Parks and Wildlife Department, USDA Natural Resource Conservation Service (NRCS), Texas A&M Forest Service (TFS), TTU Llano River Field Station (TTU-LRFS), the Texas Commission on Environmental Quality (TCEQ), and Texas State University-River Systems Institute to conduct the Texas Riparian and Stream Ecosystem training project. The project supports the Texas Nonpoint Source Management Program’s goal of protecting and restoring water quality. It provides training to land owners, land managers, water and natural resource professionals, and the general public in impaired watersheds through the help of local partners. Only a portion of the attendees responded if they owned or managed land for a total of over 97,846 acres impacted by this project, which does not include the improvements made by professional staff, who in their jobs are impacting even more land management across Texas.

Authors: L. Gregory, T.J. Gentry, M. Mukherjee, R. Rodriguez, E.A. Casarez, J.A. Truesdale

For more than a decade, the Texas BST Program has successfully identified sources of E. coli in dozens of watersheds across Texas. Comprehensive BST has been completed by UTSPH EP and SCSC for the following watersheds: (1) Lake Waco and Belton Lake, (2) San Antonio area, (3) Lake Granbury, (4) Buck Creek, (5) Leon and Lampasas Rivers, (6) Little Brazos River tributaries, (7) Big Cypress Creek, (8) Leona River, (9) Attoyac Bayou, (10) Arroyo Colorado, (11) Navasota River, (12) Big Elm Creek, (13) Plum Creek, and (14) the Trinity River in Tarrant Regional Water District’s service area. A Texas E. coli BST Library has been developed based on known source isolates from these and other (i.e. Upper Trinity River and Upper Oyster Creek) watersheds.

The Texas E. coli BST Library is dynamic, with new isolates being added with each successive BST project. To support maintenance, expansion, and use of the library and other BST tools, TWRI, UTSPH EP, and SCSC collaborated to: (1) further evaluate and refine the Texas E. coli BST library by assessing geographic and temporal stability, composition, average rates of correct classification, diversity of source isolates of the updated library, and working to develop/refine source-specific PCR markers, (2) support BST efforts in high priority watersheds, and (3) provide outreach regarding BST

Authors: M. Schramm, A. Berthold, C. Entwistle, K. Peddicord

The Lavaca River Watershed Protection Plan is a guidance document developed with local stakeholder working to reduce bacteria loads entering the Lavaca River and its tributaries. The Lavaca River and Rock Creek (a major Lavaca River tributary) are on the 303(d) List of Impaired Waterbodies due to elevated indicator bacteria that exceeds Texas water quality standards for recreation. Texas Water Resources Institute facilitated meetings and workgroup sessions with local stakeholders to identify potential bacteria load sources and prioritize locally feasible management measures.

A 9.29 × 10¹⁴ cfu per year reduction in bacteria loads is required in the Lavaca River to meet water quality standards. Rocky Creek requires a 1.39 × 10¹⁴ cfu per year reduction in bacteria loads. In order to achieve these reductions, stakeholders identified a diverse set of management measures and schedule for implementation. This document provides stakeholder guidance for implementing, tracking progress, and measuring success towards achieving improved water quality in the Lavaca River Watershed.

Authors: D. Boellstorff, D. Gholson, D. Kalisek, J. Smith, R. Gerlich, A. Truong, A. Berthold, A. Jantrania

This report highlights the trainings and screenings of the Continued Statewide Delivery of the Texas Well Owner Network project, funded by a state nonpoint source grant provided by the Texas State Soil and Water Conservation Board to the Texas A&M AgriLife Research and Texas A&M AgriLife Extension Service’s Texas Water Resources Institute, in partnership with the Departments of Soil and Crop Sciences and Biological and Agricultural Engineering at Texas A&M University.