The Delaware Department of Natural Resources and Environmental Control has given Delaware’s portion of the Brandywine watershed a C-plus and has offered recommendations for improvement.

Published by the Wetland Monitoring and Assessment Program, the report covers the eight sub-watersheds that compose the Brandywine in New Castle County. It encompasses 72,969 acres.

During summer 2019, environmental scientists collected data on the plants, hydrology and wetland buffer disturbances from 68 random sites within the watershed. Using stressor checklists and biological metrics, they determined the wetlands in the watershed to be in moderate condition, falling in the lower end of those previously rated.

The scientists found the most common stressors to be fill and structures interrupting water flow, as well as invasive species, development, roads and mowing in the surrounding landscape.

More details can be found here.

The report also found that approximately 3% of the land area of the Brandywine watershed is covered by wetlands. The watershed also contained some Category One wetlands, which are rare in Delaware.

The data was used to create a technical report and a more user-friendly “watershed report card,” which condenses general information on the watershed, summarizes environmental indicators of wetland health and showcases what the public can do to help the Brandywine.

Mapping analysis estimated that, by 2017, 26% of wetland acreage in the watershed had been lost, mostly due to human impacts.

These impacts reduce wetlands’ ability to perform fully, diminishing their role in controlling flooding and erosion, improving water quality, storing excess rainwater and providing ecosystem services for both people and wildlife.

Based on the results of this study, the department made recommendations targeting scientists, public decision-makers and landowners, including maintaining adequate wetland buffers, restoration activities, increasing education and outreach, using best management practices and suggesting that landowners protect wetlands on their properties.