Lake Whitney Comprehensive Study

Project Title: Lake Whitney Comprehensive Assessment: Phase IA – Physical Limnology
Funding Agency & Period: EPA, 2005-2007
Project Management: Sharon Daugherty (EPA), Robert Doyle, John Dunbar, Peter Allen, Bruce Byars (Baylor)
Funding Summary: Phase IA (05-07) $396,400; Future phases- pending

Task 1. Bathymetry and sediment surveys.  The goal of the bathymetric and sediment surveys is to generate maps of the current water depth and sediment thickness within LakeWhitney to serve as the foundation for future evaluations and modeling efforts.  Dr. John Dunbar is working with collaborators at the TX Water Development Board to conduct this work.

Task 2. Salinity Assessment. This task will conduct a spatially and temporally robust salinity assessment of the reservoir. Quarterly sampling of LakeWhitney to determine fine scale salinity profiles utilizing the electrical resistivity method.  The electrical resistivity method is used to remotely determine horizontal and vertical variations of electrical resistivity from measurements made along surface profiles.  Additionally, three permanent buoyed stations will provide continuous information on the principle factors related to lake salinity (conductivity and temperature) as well as pH and dissolved oxygen.

Task 3. Development of Watershed and Reservoir Hydrodynamic Models.  Provide models that can be used to provide deterministic predictions of salinity levels and patterns on LakeWhitney under various climatic conditions.  Review available models and select an existing model for use. Input data as available and calibrate the model based on known water quality at selected locations.   Verify model with a second data set collected as part of this study.  Predict conditions in water quality and quantity based on possible management and climate scenarios.

Task 4. Conduct a preliminary water quality and plankton community assessment. [TASK TO BE COORDINATED WITH BRA, TPWD AND TCEQ] Monthly sampling will be conducted at three permanent stations on LakeWhitney.  Field parameters (temperature, conductivity, DO, pH, turbidity and phytoplankton fluorescence) will be measured at 1 m intervals through the water column with a YSI 6600 (multiparameter datasonde including 2 optical ports for turbidity and chlorophyll fluorescence).  Water samples will be collected and analyzed by CRASR for a suite of chemical and biological parameters including chlorophyll a, SRP, TP, NO2 + NO3, NH4, TN. Phytoplankton and zooplankton samples will be collected and preserved for analysis by TPWD personnel.  A water sample will be collected and stored for TPWD analysis of Prymnesium parvum toxins by TPWD.

Task 5. Environmental Education.  The status of knowledge of local residents and stakeholders of LakeWhitney will be measured by implementation of a watershed/water quality knowledge instrument developed and tested by Dr. Ken Dickson at the University of North Texas. The instrument will be modified slightly to address unique factors related to LakeWhitney, including salinity and golden algae.  This survey will be done by trained pollsters using appropriate random phone interviews.   Based on the results of this survey, we will design appropriate educational opportunities to be implemented under future funding.