Presque Isle, Pennsylvania

About six million people per year visit the State Park at Presque Isle, near Erie, Pennsylvania. The park is a sandspit, nearly 10 kilometers long, that has built out from the Lake Erie shore. The narrow neck connecting it with the mainland is eroding as fast as 2.5 meters per year. Large harbor jetties built in the 1800's along the Lake Erie coast in Ohio may have trapped much of the sediment that is carried eastward by longshore currents. The U.S. Army Corps of Engineers has spent millions of dollars over the past century to stabilize the area, but the problems continue. In the mid-1970's, an attempt was made to replenish the beach on Presque Isle; unfortunately, the dark sand chosen as fill contained too much calcium carbonate, which cemented the sand particles to form an escarpment as much as 1 meter high. Below the sand scarp, the natural beach sand continues to erode. Recently, the Corps of Engineers has begun a project to construct a series of 58 segmented breakwaters at a cost of $30 million to protect Presque Isle.

Top: Erosion threatens the highway along the neck that connects Presque Isle to the Pennsylvania shore. Bottom: Darker sand used for beach replenishment at Presque Isle forms a 1-meter-high scarp.