 Sites chosen for surface-water sampling
include indicator and integrator sites. Indicator sites are located at
outlets of drainage basins with homogeneous land use and physiographic
conditions. Basins are chosen to be as large and representative as
possible while still encompassing primarily one environmental setting. An
environmental setting is a land area characterized by a unique, homogenous
combination of natural and human-related factors. Integrator sites are
located downstream of drainage basins that are large and complex and often
contain multiple environmental settings. Most integrator sites are on
major streams with drainage basins that include a substantial portion of
the study unit area.
La Moine River at Colmar,
Illinois
The La Moine basin is 655 square miles and is in the
Galesburg physiographic subsection. The land use is mostly corn and
soybean row crop agriculture, and 12% of the basin is forested. The
forested areas are mostly within the riparian zone. There is little urban
land use.
Panther Creek near El Paso,
Illinois
This basin (94 square miles) lies in the
Bloomington Ridged Plain physiographic province. It is approximately
90% corn and soybean row crop agriculture with almost no urban land use.
Historical discharge and water-quality data are available.
Mackinaw
River at Green Valley, Illinois
This large basin (1,073 square miles) is downstream from the Panther
Creek near El Paso indicator site. The basin lies entirely within
the Bloomington Ridged Plain subsection of the Till Plains section of the
Central Lowlands Physiographic Province. The land use in the basin is over
90% corn and soybean agriculture. The Mackinaw Basin is the
model for a Illinois Nature Conservancy Project to enhance cooperation
among land owners to maximize the best management practices by farmers
and other land owners. Woodford County, in the Mackinaw Basin, has
the highest rate of no-till farm management in Illinois.
Sangamon River at
Monticello, Illinois
The Sangamon basin is 550 square miles.
This basin lies entirely within the Bloomington Ridged Plain physiographic
subsection. The land use in the basin is roughly 90% corn and soybean row
crop agriculture with insignificant urban area. Historical discharge and
water-quality data are available as well as historical intensive pesticide
data from the Mid-Continent Herbicide Initiative.
Sangamon River near
Oakford, Illinois
The Sangamon River is the largest tributary
(5,093 square miles) to the Illinois River within the Lower Illinois
River Basin (LIRB). The Sangamon River Basin is roughly one-third of the
LIRB area and is the largest tributary integrator. The basin contains all
of the LIRB major urban areas outside of the Peoria area (Springfield,
Decatur, and Bloomington-Normal). The basin is roughly 90% corn and
soybean agriculture, and it includes the drainage for the intensive
indicator basin - Monticello.
Illinois River at Ottawa
(Starved Rock), Illinois
This is the major input of water and
sediment to the LIRB. The watershed above the LIRB covers 11,000 square
miles. Land use above this site is urban (Chicago Metropolitan area) and
agricultural (Wisconsin, Indiana, and Illinois). A former National Stream Quality Accounting
Network (NASQAN) site that operated through 1995 is located about 10
miles upstream.
Illinois River at
Valley City, Illinois
The basin covers 27,000 square miles and
is the only surface-water outlet from the LIRB. This site was used by the
USGS Mid-Continent Herbicide initiative for extensive and intensive
herbicide data collection.
Indian Creek near Wyoming,
Illinois
This basin (63 square miles), a part of the
Spoon River basin, lies in the Galesburg Plain physiographic province
subsection. It is roughly 90% corn and soybean row crop agriculture, and
has no significant urban area. Historical discharge and water-quality data
are available.
Personnel to contact about a specific subject are listed
on the staff page.
U.S. Department of the Interior
U.S. Geological Survey
221 North Broadway, Urbana, IL 61801, USA
URL: http://il.water.usgs.gov/proj/lirb/sw/site_descrip/index.html
Maintainer: djfazio@usgs.gov
Last modified: 13:41 CST Thurs 11 May 2000
|
Home
Surface
Water
Site
Descriptions
