DNREC Publishes Report on Wetlands Health
DNREC's Wetland Monitoring and Assessment Program today announced completion of the final report on the health of wetlands located in New Castle County's Christina River Watershed.
To view the full report and the report card, or for more information on assessment methods, click here.
The Christina River originates in Landenburg, Pa., and flows 35 miles eastward through Newark, Christiana and Newport, Del., before emptying into the Delaware River through the Port of Wilmington. One of only five watersheds that make up Delaware's Piedmont drainage basin, the Christina River Watershed covers a little over 49,000 acres and is 60 percent urban development. Wetlands make up approximately 10 percent of the watershed.
“Throughout Delaware's history, the Christina River and its wetlands have seen significant changes, from re-routing the river for transportation, to diking and filling wetlands for industrial development. The remaining wetlands in the Christina River watershed are crucial for protecting communities from flooding and cleaning surface waters,” said DNREC Environmental Scientist Alison Rogerson, program lead for Wetland Monitoring and Assessment.
In the summer of 2011, teams of wetland scientists from DNREC's Division of Watershed Stewardship's Watershed Assessment Section and the Partnership for the Delaware Estuary visited randomly-selected sites within the Christina River Watershed: 32 non-tidal flats, 40 non-tidal riverine wetlands, two non-tidal depressions and 30 estuarine tidal wetlands. The teams used condition assessment checklists and biological metrics to determine how well the wetlands were faring. Indicators such as the presence of invasive plants, ditches that drain wetlands, or sources of pollution adjacent to wetlands are examples of how wetland health can be adversely impacted.
The organizations combined their data to create a 56-page technical report that summarizes not only the health of these wetlands, but also examines how wetland acreage has changed in recent decades, and discusses how trends in land use have and will impact wetlands across the watershed.
“This report includes management recommendations such as incorporating wetland creation into urban planning, encouraging buffers around streams and wetlands, and exploring innovative restoration techniques using dredge materials and living shorelines,” Rogerson said. “In a highly developed watershed, voluntary restoration and protection options, in addition to smart land use planning, will help remaining wetlands perform their natural services for us.”
Compared to other watersheds assessed in Delaware, wetlands in the Christina River Watershed are in considerably poorer condition. The majority were classified as severely stressed wetlands, which means the wetlands had numerous alterations to vegetation, hydrology, and/or soils. These changes diminish the wetlands' ability to minimize flooding, control erosion, improve water quality and provide a biologically rich habitat for plants and animals.
To combat disturbances to wetland health and loss of acreage, the groups produced seven management recommendations:
- Preserve remaining Delmarva Bays (coastal plain ponds), a regionally-unique wetlands classification.
- Incorporate wetland creation and restoration into urban planning.
- Explore opportunities to use clean dredge material for wetland creation/restoration.
- Encourage alternative shoreline protection designs, such as Living Shorelines.
Develop incentives and encourage maintaining vegetated buffers along riverine and tidal wetlands. Control the extent and spread of the non-native, invasive common reed (Phragmites australis).
The Christina River Watershed Report has been summarized into a report card and presentations for targeted audiences. This report is the sixth in a series of directed watershed studies throughout the state. These reports and the work of the Wetland Monitoring and Assessment Program are made possible by EPA Region 3 Wetland Program Development funding.