Comparison of Constructed and Natural Wetlands in Delaware

WRD PROJECT #: MD134
PROJECT CHIEF: Hudson, David C.
BEGIN DATE: 01-October-1996
END DATE: 30-September-2003

Customers currently supporting the project:

Delaware Department of Transportation
Delaware Geological Survey

Problem

A 100-acre farm site in southern Delaware, known as the Eskridge property, was utilized by the Delaware Department of Transportation (DelDOT) from 1992 to 1996 as a borrow pit to supply sand and fill dirt for the renovation and widening of U.S. Route 113. During road construction, the U.S. Army Corps of Engineers granted DelDOT a permit to fill in 45 acres of natural, forested, wetlands, but mandated that replacement wetlands be created at a minimum 2:1 ratio to mitigate for the loss. DelDOT created a wetland at the Eskridge site, which is being monitored by the USGS. The USGS is working with DelDOT through the Delaware Geological Survey (DGS) to monitor shallow ground-water hydrology of a naturally occurring, forested wetland adjacent to the site in Redden State Forest for comparison.

Objectives

Monitor ground-water levels in the created wetland at Eskridge, and in nearby Redden State Forest over a period of 7 years from 1997 to 2004. Provide data annually to DelDOT.

Approach

A series of 50 shallow wells have been installed at Eskridge and Redden. Manual tape-down water-level measurements are taken monthly at 42 of these wells, and the remaining 8 have continuous data recorders installed. Precipitation data are also collected from a Delaware State Forest Service gage in Redden State Forest.