Monitoring littoral sediment accretion and erosion at Forest Park Beach, Lake Forest, Illinois

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:7069823

Trask, C B; Chrzastowski, M J ^[1]

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1. Illinois State Geological Survey, Champaign, IL (United States)

Forest Park Beach, a coastal-development project on the shore of Lake Michigan at Lake Forest, Illinois, consists of a series of segmented, rubble-mound breakwaters that form four beach cells and a small-boat launch basin. The project was designed to have minimal impact on local littoral-transport processes. The 9-hectare footprint extends no more than 107 m lakeward of the preconstruction shoreline; the arcuate plan for the project was designed to facilitate littoral sediment bypass. In order to evaluate the project's impact on littoral processes, the City of Lake Forest is required to conduct a monitoring program to identify any adverse effects such as updrift accretion and downdrift erosion. Annual and semi-annual monitoring has been underway since project completion in 1987. In 1991, the Illinois State Geological Survey (ISGS) began independent data collection and review of the annual monitoring data. As of the 1992 ISGS monitoring, the project is allowing for the development of natural bypass by the littoral-sediment stream. A bar occurs in 0.9 to 1.2 m of water on the north side of the project and continues as an accretionary wedge along the lakeward side of the breakwaters for approximately two-thirds of the project length. One adverse impact is that the beach cells are acting as traps for fine sand, with the greatest entrapment in the three northern (updrift) cells. Comparison of 1987 and 1992 profiles from the beach cells indicates nearshore accretion of as much as two meters. To date no detrimental effects to shoreline properties have been documented downdrift of the project.

• OSTI ID: 7069823
• Report Number(s): CONF-9303210--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:3
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
COASTAL REGIONS
CURRENTS
DEPOSITION
DEVELOPED COUNTRIES
EROSION
GEOLOGIC DEPOSITS
GREAT LAKES
ILLINOIS
LAKE MICHIGAN
LAKES
NORTH AMERICA
SEDIMENTATION
SEDIMENTS
SHORES
SURFACE WATERS
USA
WATER CURRENTS