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Control-Structure Ratings on the Fox River at McHenry and Algonquin, Illinois

January 1, 2009

The Illinois Department of Natural Resources-Office of Water Resources operates control structures on a reach of the Fox River in northeastern Illinois between McHenry and Algonquin. The structures maintain water levels in the river for flood-control and recreational purposes. This report documents flow ratings for hinged-crest gates, a broad-crested weir, sluice gates, and an ogee spillway on the control structures at McHenry and Algonquin. The ratings were determined by measuring headwater and tailwater stage along with streamflow at a wide range of flows at different gate openings. Standard control-structure rating techniques were used to rate each control structure.

The control structures at McHenry consist of a 221-feet(ft)-long broad-crested weir, a 4-ft-wide fish ladder, a 50-ft-wide hinged-crest gate, five 13.75-ft-wide sluice gates, and a navigational lock. Sixty measurements were used to rate the McHenry structures. The control structures at Algonquin consist of a 242-ft-long ogee spillway and a 50-ft-wide hinged-crest gate. Forty-one measurements were used to rate the Algonquin control structures.

Publication Year 2009
Title Control-Structure Ratings on the Fox River at McHenry and Algonquin, Illinois
DOI 10.3133/sir20095186
Authors Timothy D. Straub, Gary P. Johnson, Jon Hortness, Joseph R. Parker
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2009-5186
Index ID sir20095186
Record Source USGS Publications Warehouse
USGS Organization Illinois Water Science Center