Illinois State Library

Document Identification

Title

• Fox River streamflow assessment model: 1999 update to the hydrologic analysis

Description

• The Illinois Streamflow Assessment Model (ILSAM) was developed to provideneeded streamflow information to watershed managers and planners. This specialized software program was developed for use on a personal computer to provide estimates of the long-term expected magnitude of streamflow at various frequencies for any stream location along a major stream in a watershed.The purpose of this study was to update ILSAM for the Fox River Basin, a modeloriginally developed in 1988. Over time, climate variability and changes in humanfactors, such as land and water use, and water resource projects, can greatly affect the quantity and distribution (both in space and time) of surface waters in a river basin. For this reason, the data sets used by ILSAM were designed to be updated periodically, perhaps every 5 to 15 years. The frequency of and need for updates are governed by the rate at which streamflow conditions in the watershed change over time. The model update for the Fox River Basin addresses four areas that influence the flow frequencies and their estimation:- Increases in population, overall water use, and the resulting effluent discharges.- A new public water supply withdrawal from the Fox River and increases inmagnitude of existing withdrawals.- General increases in streamflow magnitude caused by climatic variability and the overall increase in average precipitation.- Adoption of improved regional equations from which to estimate flow at ungaged s i t e s .

Access This Publication

1. Fox River streamflow assessment model: 1999 update to the hydrologic analysis (20060929185733_ISWSCR-649.pdf).
Document Size:285029 Software: Adobe Acrobat Version: 7.0