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 Groundwater hydrology of a naturally occurring, forested wetland adjacent to the site in Redden State Forest for comparison.

Objectives

Monitor Groundwater 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.