RESTORING THE LOST RESACAS: WETLAND RESTORATION IN THE LOWER RIO GRANDE VALLEY, TX

Area of Science:

• Ecological restoration
• Wetland science
• Environmental management

Background:

• Resacas (oxbow wetland lakes) in the Lower Rio Grande region have significantly declined, threatening water quality and quantity in this underserved, largely Hispanic area.
• Altered natural landscapes due to flood control and agriculture have led to decreased biodiversity and bacterial water pollution.
• Urban fragmentation by infrastructure has reduced green space, impacting public health and ecological connectivity.

Purpose of the Study:

• To present ecological strategies for restoring vanished resacas in the Lower Rio Grande region.
• To identify optimal sites for resaca restoration through suitability analysis and vacant land identification.
• To develop resaca-ready programs addressing identified barriers to restoration.

Main Methods:

• Conducted a suitability analysis to identify potential habitat areas and optimal design sites.
• Created a resaca network for wildlife habitat and performed a comprehensive site analysis.
• Utilized the Long-Term Hydrologic Impact Assessment Model (L-THIA) to quantify stormwater runoff capture and pollutant reduction.

Main Results:

• Restored resacas capture an additional 1,486,703 ft3 of annual stormwater runoff.
• Restoration significantly reduces pollutants: 89.5% of phosphorous, 86.4% of suspended solids, and 84.1% of fecal coliform.
• Identified recreational, mobility & safety, and population-based barriers, with corresponding programs developed to address them.

Conclusions:

• Resaca restoration offers a viable ecological strategy for improving water quality, managing stormwater, and enhancing biodiversity in the Lower Rio Grande.
• The project revitalizes vacant land, provides flood control, and contributes to improved public health in a vulnerable region.
• Restoration efforts support vital ecological functions, including serving as critical habitat within migratory bird flyways.