White Clay Creek Stream Watch Project


White Clay Creek

The White Clay Creek watershed (107 square miles or 280 km2) is located in Chester County, Pennsylvania and New Castle County, Delaware. It flows into the Christina River near Newport, Delaware, which in turn, flows into the Delaware River near Wilmington. The White Clay Creek (WCC) is composed of three main branches in Pennsylvania (East, Middle, and West) and three main tributaries in Delaware (Middle Run, Pike Creek, and Mill Creek).

In 2000 Federal legislation designated WCC and its tributaries as a National Wild and Scenic River signifying it as possessing outstanding scenic, wildlife, recreational and cultural value. That marked the first time an entire watershed — rather than just a section of river — had been designated.

Approximately 17% of the watershed is protected open space including the WCC Preserve (PA) and WCC State Park (DE). A variety of habitats provide a rich diversity of fish and wildlife: 21 species of fish, 33 species small mammals, 27 species of reptiles and amphibians, and over 90 species of breeding birds.

It is also a cultural and historic location that was originally settled by the Lenape Native Americans and presently has 38 properties on the National Register of Historic Places. In addition, nearly 130,000 people get their drinking water from the WCC and the Cockeysville aquifer that underlies portions of the watershed.

Stream Watch volunteers

The White Clay Watershed Association’s (WCWA) Stream Watch Program was initiated by WCWA volunteers and the Stroud Water Research Center, and later joined by the Delaware Nature Society, because of concerns of rapid land development in the WCC watershed.

Sampling of aquatic macroinvertebrates (insects and non-insects such as worms and mollusks) was chosen because they have been shown to be cost-effective, commonly used, and widely accepted tool in water quality monitoring programs. Macroinvertebrates are advantageous in evaluating water quality because they have relatively diverse assemblages (100-200 species) and as a group are a sensitive measure of environmental change and stress. Their limited mobility and relatively long life spans (a few months to a year) make the presence or conspicuous absence at a site a meaningful record of environmental quality during the recent past, including short-term infrequent events that might be missed by periodic water sampling.

Macroinvertebrate sampling started in 1991 and has continued through 2008 with 15 of the last 18 years sampled. A total of 18 sites were monitored: A total of 18 sites were monitored: 12 sites in PA were sampled ~15 yrs (1991-2008), three sites in DE were sampled ~9 yrs (1995-2008), and three sites were sampled infrequently. The goals of this project were:

  1. to evaluate water quality in White Clay Creek and its tributaries using aquatic macroinvertebrates, and
  2. to make data available to local education outreach and community groups in order to encourage efforts to assess, improve, and/or protect water quality in White Clay Creek.

Project Results

Read more about the study by visiting the following pages. (You can also access pages from the menu in the sidebar).

Want to spread the word about water quality in White Clay Creek? Download a printable brochure.

You can also download the full Stream Watch report.


The data collection and macroinvertebrate identification were accomplished with the help and dedication of multiple volunteers from the  White Clay Watershed Association, Stroud Water Research Center and the Delaware Nature Society.

This report and web pages development were prepared for the White Clay Creek Watershed Management Committee (White Clay Wild & Scenic Program) with funding provided by the National Park Service Wild and Scenic Rivers Program and the Stroud Water Research Center Endowment.  The views and conclusions contained in the document and web pages are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Government. Mention of trade names or commercial products does not constitute the endorsement by the U.S. Government.