North and Central Watersheds Characterization Phase II
Steering Committee Workshop
Clean Water Act’s Section
319 Nonpoint Source Pollution Program
Funding provided by the Texas Commission on Environmental Quality through a Clean Water Act § 319(h) grant from the U.S. Environmental Protection Agency.
To address non point source (urban runoff, stormwater runoff) pollution problems
Phase I: Watershed Characterization
2019-2021- UTRGV Thesis and Publication 2021,
Phase II: Water Quality Data Collection
2022-Present- RATES Principal Investigator
Deliverable: Stakeholder Meeting
Requirement for Project Tasks in Quarter 4
Project Status, Scope of Work, Data Applications, QAPP, Timeline
Objective
Characterize primary watersheds in the Lower Rio Grande Valley to address and assess levels of impairments.
Three Primary Waterways:
- Raymondville Drain
- Hidalgo Willacy Main Drain
- IBWC North Floodway
Background
North and Central Watersheds
The is designated as an impaired waterway for high concentrations of bacteria and low dissolved oxygen (DO). North and Central (NC) primary waterways (Raymondville Drain, Hidalgo Willacy Main Drain, and IBWC North Floodway) in the Lower Rio Grande Valley (LRGV) have not been characterized which can potentially be the flow water carriers of these contaminants into the LLM.
Importance
Recreation activities: Fishing and Swimming
Aquatic Life
Laguna Atascosa Wildlife Refugee: Protects nearly 100k acres of habitat
Low- Dissolved Oxygen Information:
TCEQ REPORTS
Scope of Work
Phase II Water Quality Data Collection
Continuous Water Quality Data Collection by leveraging TWDB FWF monitoring stations and conducting quarterly water quality samples and flow measurements.
- Extend Phase I Lower Rio Grande Valley-North and Central Watershed Characterization (UTRGV).
- Provide a combination of continuous and event-based monitoring
- RTHS: Leverages 3 monitoring stations commissioned by TWDB-FWF
- Quarterly- water quality and hydrodynamic measurements
- Dissolved Oxygen, Water Temperature, Conductivity, pH, Nitrate/Nitrite, Total Phosphorus, Total Nitrogen (TKN), and E. coli
- ADCP discharge transects and flow measurements to develop discharge rating curves as a function of stage height
Raymondville Drain
- City of Edinburg, Raymondville, San Perlita
Raymondville Drain
Rodriguez Road
Hidalgo Willacy Main Drain
- Alton, Palmhurst, Mission, McAllen, Pharr, Edinburg, Elsa, Edcouch, La Villa, Lyford
Hidalgo Willacy Main Drain
South of Willamar, FM 1420
:
IBWC North Floodway
- San Juan, Alamo, Donna, Weslaco, Mercedes, La Feria
IBWC North Floodway
Data Applications
Data Applications
Example:
Raymondville Drain Water Samples and Flow Measurements
Total Phosphorus levels increased up to 1.8 mg/L
Water Quality for Phosphorus. The red line represents the screening level of 0.7 mg/L as per TCEQ standards. CRP collected 8 Samples, and TWDB-FWF collected six samples.
Quality Assurance Project Plan Development (QAPP)
Contract between TCEQ and RATES
Guidelines and framework of the monitoring activities and data management
Value
- Continuous water quality and stream stage heights.
- Address measurement bias
- Can be combined with derived flows to quantify contaminant loads
- Ability to characterize episodic events (e.g. spills, extreme weather)
18 months of monitoring.
Start date pending approved QAPP.
Project duration: 24-36 months
- ADCP Calibration
Project Time Line
9/1/2022
Contract Executed
3/1/2023
QAPP Draft
5/1/2023
Received QAPP Revisions
6/2023
Sent QAPP
7/2023
Received 2nd batch of comments from TCEQ
8/7/2023
Final QAPP Review to TCEQ
9/1/2023
Begin Field Observations
10/31/2024
End Field Observations
8/30/2025
Final Report
Questions
TWDB 2 and TWDB 1 Stations
RTHS Platform to view data results
