The 61-mile Illinois shore of Lake Michigan is the most populated coastal reach in the Great Lakes and except for the northern 10 miles is fully engineered. North of the City of Chicago is the "North Shore," a 24-mile stretch of urban lakeshore with private and municipal properties typically protected by groin fields and stone revetments.

The North Shore coastal geology includes eroding glacial clay-till bluffs and lakebed containing about 10% sand. Photographs of the North Shore from the 1880s through the 1930s show extensive development of rock-filled wood crib piers. The piers performed like groins, trapping sand on their northern sides. In unprotected areas, bluff erosion rates averaged 1.5 feet per year (approximately 8.3 yd3 of sediment lost per linear foot of lakeshore per year). By the 1950s, most of the piers were replaced with steel sheetpile groins. With the progressive armoring of the lakeshore, the primary source of sand, bluff erosion was cut off. By the 1980s many of the groins were empty. Further, nearshore lakebed erosion began to undermine the ends of the groins as the bottom profile steepened.

In the late 1980s, coastal engineers recognizing the sediment-starved nature of the system began constructing shore-connected stone breakwaters artificially nourished with coarse sand. In two municipal beach systems, regulators required monitoring to assure no negative impacts. At Sunrise Park, Lake Bluff, a single cell breakwater system was monitored from 1992 to 1999. A groin protected "control" beach was also monitored. During two periods of rising lake levels, the project beach gained 0 to 1 yd3 of sand while the control beach lost approximately 0 to 2.6 yd3 of sand per linear foot of lakeshore. During two periods of falling lake levels, the project beach lost 1 to 4 yd3 of sand while the control beach lost 0 to 0.5 yd3 sand per linear foot of lakeshore. At Forest Park Beach, Lake Forest, a four-cell beach system was intensively surveyed from 1991 to 1995. The Illinois State Geological Survey reported a period of sand accretion (during rising lake levels) followed by a period of erosion (during falling lake levels). No adverse impacts on downdrift beaches or shore protection structures were reported in both studies. Monitoring will continue at the Sunrise Park facility to confirm or deny the hypothesis that breakwaters perform (in terms of ability to hold sand) better than groins during rising water levels and worse during falling water levels.

Today more than 18 breakwater-beach systems have been permitted in Illinois. Regulators require a 20% sand overfill to assure that there is no net loss of sand from the littoral drift system.

Great Lakes Water Levels (from the USACE Monthly Bulletin for the Great Lakes):

Save the Date
Coastal Zone '01: Cleveland, Ohio. 15-19 July, 2001. Visit the conference web site at www.csc.noaa.gov/cz2001.
Waves ’01: The 4th International Symposium on Ocean Wave Measurement and Analysis: San Francisco, CA. 3-5 September, 2001.
Shore & Beach Protection (hosted by ASBPA and American Coastal Coalition): Washington, DC. 13-16 May, 2001. Questions or reservations, contact awoodell@rahul.net.

Special Session at Coastal Zone ’01
SAND MANAGEMENT IN THE GREAT LAKES: PAST AND FUTURE
Conveners: Mickael J. Chrzastowski, Illinois State Geological Survey
Donald E. Guy, Jr., Ohio Geological Survey

Sand management practices over the past 150 years have significantly degraded many reaches of Great Lakes’ shoreline. Sand supply to the littoral system has been reduced by capture of sand behind dams on tributaries and by armoring of the coast to prevent shore recession. Sand in the littoral system has been impounded by harbor structures, dredged from navigation channels and dumped in deep-water disposal sites, or mined from beach and nearshore areas. The results of diminished sand supply and volume have been narrower and thinner beaches, localized total loss of beaches, increased shore erosion, and modification of beach and nearshore habitats. Recognition of this degradation has prompted changes in sand management practices and prompted interest in new approaches to restore and enhance beaches. This session will explore the impacts of past practices, the simple innovative efforts taken to improve sand management, and the new focus on a more holistic approach to the stewardship of sand resources along the Great Lakes. If you are interested in contributing a talk to this session, please contact either Michael Chrzastowski (chrzasto@isgs.uiuc.edu) or Don Guy (don.guy@dnr.state.oh.us).

Word from the President: Charlie Shabica (e-mail: charles@shabica.com) Do you have a favorite urban beach or park? ASBPA and other agencies are sponsoring a large format book on urban coasts. The book will be a primer showing how communities have successfully provided human access to the coast. The premise is that the shore represents in human terms the boundary between the land, the sea (also lakes and rivers) and the cosmos. City planners have long recognized the value of public parks for the mental health of their citizenry. In this book, we propose to showcase projects where municipal leaders, planners, architects, engineers and citizens cooperated to produce first class solutions to coastal access. Examples include the Chicago lakefill, Jones Beach NY, Kansas City Riverfront and others. Please e-mail Orville Magoon (omagoon@guenoc.com) or Charlie Shabica if you’d like to nominate a site for the book or present a paper in THE URBAN BEACH INITIATIVE session at Coastal Zone 01. Criteria include, but are not limited to: safe, low cost visual and physical access to clean water and grand vistas. The tentative book format includes: project description, photos, drawings, site information, statistics and construction and maintenance costs. We estimate 8 to 10 pages per site.

GLSBPA
550 Frontage Road
Suite 3400
Northfield, Illinois 60093