ABSTRACT: Connecting the Link between Land Use and Stream Health in the

University of Delaware Experimental Watershed

DWRC 2001 – 2002 Intern: Tara Harrell

Project Advisor: Gerald Kauffman

Although people depend on water for their everyday lives, its source is

generally taken for granted. The geographic area of land that drains into

a waterway, regardless of size, is known as a watershed. Although the

larger bodies of water may seem more significant, it is the compact

watersheds where research can be focused. Student researchers of the

University of Delaware Water Resources Agency (UDWRA) have delineated an

experimental watershed through the University of Delaware campus which

includes both the northern Piedmont Plateau and the southern Coastal

Plain. The land use in these areas is rapidly changing, and the amount of

impervious services, such as roads and driveways, is increasing. A

negative relationship between land use and stream health was found in the

Piedmont Plateau, and a report card for establishing a user-friendly way

of tracking watershed health through the years was developed. The purpose

of this project is to continue to research the link between stream health

and land use and update the watershed report card for the Piedmont Plateau

and the Coast Plain while exploring different methods and procedures. In

order to answer this pressing issue, stream sampling and chemical surveys

were completed at each of the sampling stations through the watershed. The

University of Delaware Water Resources Agency (UDWRA) was fortunate enough

to have contacts in New Zealand. The National Institute of Water and

Atmospheric Research (NZNIWA) has donated a Stream Health Monitoring and

Assessment Kit to the WRA. A comparison between the two habitat

assessment procedures will illustrate the differences and perhaps call for

a modification of the current UDWRA assessment technique. Geographic

Information Systems (GIS) software was used in order to determine the

amount of land use and impervious surface in each sub-basin. The

information gathered was analyzed by the application of the report card.

Because the report card is such a standardized method, it is very easy to

compare and contrast the streams and areas. The GIS software was analyzed

using standard techniques and aerial maps in public circulation. GIS

software is the most reliable and best method of land use and area

research. The results were as expected. In the NZ-NIWA method, all of

the measurements are extremely quantitative, whereas the USEPA methods

were more subjective. The Overall Watershed Health Grade of the Piedmont

Watershed was a C+, which has fallen from a B- in 2001. The stream in

this watershed with the highest percentage of impervious cover had the

lowest stream quality, in conclusion with the thesis of this report. The

Coastal Plain in 2002 received an Overall Watershed Report Card Grade of

C, which is another decrease in total watershed health. The Coastal Plain

Watershed received a C+ in 2001. Tributary 3, which had the lowest

percentage of impervious cover, had the highest water quality grade. The

stream with the lowest overall grade had the highest amount of negatively

impacting land uses and highest percentage of impervious cover. Future

researchers will be able to update and modify the Experimental Watershed

Report Card to monitor temporal changes in the surrounding land.