NewsDrop-February-2025

HEALING A SCAR

By: Brent Doty Research Manager, Aquifer Science

Project SCAR features the long-term observation of land management practices designed to diffuse stormwater energy and reduce sediment loading, potentially revers ing erosion and improving water quality. EAA scientists and contractors worked together to design and install simple NBS structures within and around the scar channel and local watershed. A team featuring EAA scientists, interns, and contractors carefully built rock and brush structures along the length of the scar feature and nearby tributary channels. Over time, as plants grow within the NBS structures, EAA scientists hypothesize that additional natural water filtering will occur as the site matures. An automated trail camera, routine drone captures, and boots-on-the-ground monitor ing will keep track of any physical and eco logical changes to the site over time. Looking forward, EAA scientists will also deploy automated water quality samplers to evalu ate sediment loading at the start and end of the scar area. Over the course of numerous rain events, EAA researchers hope to gather and evaluate quantifiable evidence of ero sion reduction and reduced sediment loading from incoming runoff. Stay tuned for future updates!

Drone imagery of the ‘scar’ area at the EAA’s Field Research Park (map by Jewell Lee Cozort).

Jewell Lee Cozort and Derek Hausman, EAA Environmental Scientists, monitor vegetation along the “Scar” feature at the EAA Field Research Park.

EAA scientists, interns, and contractors work together to install simple rock and brush structures at the Scar site.

HEALING A SCAR NATURE-BASED SOLUTIONS FOR WATER QUALITY AND EROSION PROTECTION

Derek Hausman and Jewell Lee Cozort carefully take measurements while assessing channel depth and vegetation at the EAA’s Field Research Park (FRP). Derek calls out a depth on a leveling rod, “three-point-two meters”, while Jewell Lee records his measurement and takes note of plant species at each interval. The two scientists are monitoring an erosional feature caused by combination of head cuts and channel incision from excessive stormwa ter runoff. EAA scientists call this erosional head-cut feature a ‘scar’, as it resembles a scar in the land scape and is markedly visible from satellite imagery.

The scar was formed and continues to increase in size due to urban development and impervious cover within the watershed upstream of the FRP. Impervious cover are surfaces in a landscape that cannot absorb or infiltrate rainfall (e.g., concrete, asphalt). During heavy rain events, stormwater run off increases as it is unable to infiltrate impervious cover. As such, it carries more energy and sediment downstream and may carry potential pollutants. The faster moving stormwater runoff erodes channel banks, thus causing the scar to grow more quickly overtime, leading to added erosion and potential contaminant transport across the sensitive Edwards Aquifer Recharge Zone.

Nature-Based Solutions and Project SCAR

SCAR (Sustainable Channel Assessment and Restoration). The development of the scar fea ture at the FRP has provided an opportunity to research two other potential benefits of NBS features – water quality improvement and ero sion protection. In concept, high energy and sediment-laden stormwater will be dissipated by the combination of natural obstacles posed by the various NBS structures. Rock structures provide armoring from erosion and offer pock ets for sediment trapping, while brush struc tures also help to reduce stormwater velocity and allow additional sediment trapping.

The completed SCAR land management features awaiting rainfall testing.

Several research projects at the FRP have featured nature-based solution (NBS) features with the goal increasing recharge to the aquifer. Rock sills, berms and swales, and other simple rock structures dot the landscape of the FRP. to slow, spread, and sink runoff, potentially increasing natural recharge. While the devel opment of the scar was at first a concern, EAA scientists quickly viewed it as an opportunity for investigation and embarked on a research effort that is coincidentally named Project

Tune in as Mollie Walton, an expert Restoration Ecologist, gives us a sneak peek into one of the amazing restoration projects happening at the Field Research Park!

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