National Water-Quality Assessment Program,
Lower Illinois River Basin Overview
Kelly L.Warner
The U.S. Geological Survey National Water-Quality Assessment
(NAWQA) study of the lower Illinois River Basin began in 1994. The study
area includes 17,960 square miles of central and western Illinois. The
basin begins at Ottawa, Illinois and extends to the confluence of the Illinois
and Mississippi Rivers at Grafton, Illinois. The study focuses on water-quality
as related to three disciplines: surface water, ground water, and biology.
The ground-water component of the study includes large-scale reconnaissance
(study-unit survey), regional land-use relations (land-use survey), and
characterizations of local ground-water conditions (flow-path or reach
study).
U.S. Geological Survey
221 N. Broadway
Urbana, IL 61801
(217) 344-0037
klwarner@usgs.gov