Protecting southwest florida's water resources: understanding the contribution of groundwater to surface water quality in the estero BAY watershed institution: florida gulf coast university…

Federal Cooperative Agreement Award Summary

Florida Gulf Coast University received a $750,000 Cooperative Agreement from the National Oceanic and Atmospheric Administration (NOAA) under the Congressionally Identified Awards and Projects program (CFDA 11.469), awarded on March 1, 2025, with a performance period extending through February 29, 2028. The project, "Protecting Southwest Florida's Water Resources: Understanding the Contribution of Groundwater to Surface Water Quality in the Estero Bay Watershed," is led by Dr. Rachel Rotz and Dr. Ahmed Elshall and addresses ecological disturbances in the Estero Bay watershed, including algal blooms and fish kills caused by groundwater-surface water interactions.

The research will deliver a comprehensive hydrological assessment and predictive modeling framework through three integrated approaches: field-based hydrograph separation and baseflow analysis, tracer-based end-member mixing modeling, and three-dimensional numerical groundwater-surface water interaction modeling using MODFLOW and SEAWAT software. The project will quantify groundwater discharge from the surficial aquifer system, measure nutrient loads (total nitrogen and total phosphorus) through systematic sampling across multiple watershed sites, and produce a functional hydrological model to inform nutrient and contaminant management strategies. These outputs will provide watershed managers with decision-support tools to enhance water resource sustainability and ecosystem resilience in the Estero Bay watershed.

Protecting southwest florida's water resources: understanding the contribution of groundwater to surface water quality in the estero BAY watershed institution: florida gulf coast university investigators: DR. Rachel rotz, DR. Ahmed elshall total proposed cost: $750,000 budget period: august 19, 2024 - august 18, 2027 the estero BAY watershed in LEE county, florida, features a hydrological system significantly influenced by shallow groundwater. This influence extends to the quantity and quality of surface waters. Recent ecological disturbances, such as algal blooms and fish kills, underscore the need for an improved understanding of how groundwater affects these surface water bodies. This proposal seeks to quantify the groundwater discharge from the surficial aquifer system into the estero BAY watersheds major rivers through a three-pronged approach: 1) applying field data analysis and hydrograph separation techniques to measure baseflow and estimate groundwater discharge, 2) utilizing tracer analyses alongside field and laboratory methods to develop an end member mixing model for quantifying groundwater discharge, and 3) employing modflow and seawat software to create a 3-dimensional, finite difference numerical model that simulates groundwater-surface water interactions and measures groundwater flux. The study will involve systematic sampling of groundwater and surface waters across multiple sites within the watershed, analyzing for total nitrogen (TN) and total phosphorus (TP). The combined use of empirical data and modeling will provide a comprehensive quantification of nutrient loads, enhancing predictions and management strategies for mitigating pollution impacts in estero BAY. These efforts aim to establish a hydrological model that will not only inform future nutrient and contaminant management strategies but also empower watershed managers with the tools necessary for making decisions that enhance water resource sustainability and ecosystem resilience, thus contributing to the preservation and enhancement of regional and similar ecosystems.