Spotlight on Presque Isle

Spotlight on Presque Isle
With the annual Best Restored Beach Awards going mainly to projects on the coasts engineers at the Corps Buffalo District decided that a Great Lakes project in general and their Presque Isle project in particular would be a good candidate. Michael Mohr of the District’s Coastal and Geotechnical Engineering Section who had been the Presque Isle project engineer was tapped to write the proposal to the ASBPA and the project was one of the winners for 2011.

The Presque Isle project was begun in October 1989 and finished in November of 1992. The district was the design engineer on the project and directed construction. The sponsor was Commonwealth of Pennsylvania Department of Conservation and Natural Resources. The contractor Durocher Marine with Stan Neff as project manager nourished the badly-eroded beach with 373000 cubic yards of sand from an offshore borrow site. They also barged in the rock for the breakwaters from Edward Kraemer & Sons Inc. Clay Center Ohio. The sand along this stretch of beach was continually eroding with the littoral material traveling eastward with enough ending up in the Erie Harbor entrance channel to require annual maintenance dredging. Mohr began his project submittal to the ASBPA with two quotes that pointed to the importance of the peninsula:

“We have met the enemy and they are ours – two ships two brigs one schooner and one sloop.” Oliver H. Perry Battle of Lake Erie 1813. (Recognized as an excellent location as some of Perry’s ships were constructed at Erie sheltered by Presque Isle Bay.)

“The peninsula of Presque Isle at Erie Pennsylvania is in many respects one of the most interesting localities… and indeed there is probably nowhere else about Lake Erie a locality where undisturbed vegetation may be studied.” O. E. Jennings Botanist 1907.

An ancient Lake Erie feature the peninsula is a National Natural Landmark which presents five different series of primary plant succession from beach to forest. It contains a greater number of endangered threatened and rare species than any other area of comparable size in Pennsylvania. As earlier military commanders had appreciated – first the French then the British and finally the Americans – the sheltered harbor behind Presque Isle gave the community strategic importance.

During the War of 1812 many American vessels were built at Erie safe from raids or attacks from the British. Perry’s vessel the U.S.S. Niagara is the only ship of her type which is still in existence from the War of 1812 and is still safely sheltered within Presque Isle Bay. The River and Harbor Act of 1824 authorized improvement of Erie Harbor and protection of the peninsula which by its position forms the harbor.

In 1986 Congress authorized the construction of 58 offshore rubblemound breakwaters and initial beach restoration. The breakwaters constructed parallel to the shore mimic nature and act as a barrier reef. They reduce storm damage encourage beach growth and allow sediment to travel through the system naturally to reach the ecologically sensitive distal end known as Gull Point which is critical habitat for nesting and migrating shorebirds.

At the time construction of this type and size of project for shore preservation was unknown in North America. Reservations concerning the project were partially allayed by the construction of three prototype breakwaters and the completion of two hydraulic model studies at the Waterways Experiment Station. These showed the breakwater size and configuration to be the most cost- effective solution.

Presque Isle is a national resource with tremendous historical significance that the Corps of Engineers and the Commonwealth of Pennsylvania are working to preserve. Limited beach replenishment is performed annually to restore sediment that moves through the system to Gull Point.

Periodic surveys aerial photographs and ecological assessments continue to show that the project is working well. The breakwater system has reduced erosion of the shore to the point where less than one-quarter of pre-project beach nourishment quantity is needed. The project is now providing a functional natural solution to protect and preserve this historic landmark. With the annual addition of sand wide beaches are maintained. The uniqueness of the plan is that while maintaining a beach the project also allows littoral material to pass through the system to nourish the environmentally sensitive distal end. The eastern end of the peninsula has been designated Piping Plover habitat. This has not been fully successful as funding constraints have limited the nourishment program below the required amount.

In 1968 there was limited acceptance of the rubblemound breakwater technology by the public and scientists and engineers within the Corps of Engineers. Common practice preferred at the time was the construction of groins bulkheads or beach nourishment. These solutions had been used in the past with moderate success. The shore of Presque Isle was littered with the skeletons of failed groins and bulkheads.

The need for large amounts of nourishment resulted in the use of sand from upland quarry pits. This sand proved to be unattractive to beach users and its flat grain shape was not conducive to nesting by shore birds. During a Coastal Engineering Research Board (CERB) meeting at Presque Isle Denton Clark of the Buffalo District presented the segmented breakwater alternative.

While there was opposition to the concept by some an eminent coastal engineer Morrow O’Brien was supportive of investigating this alternative. Three prototype breakwaters were constructed on the peninsula in 1978. Data collected at these structures was instrumental in calibrating a 3-D physical model at the U.S. Army Engineer Waterways Experiment Station. The design was accepted as effective and the project proceeded. The breakwaters are 250 to 350 feet from the shore along 5 ½ miles of shoreline in approximately eight feet of water.

Part of the design of the project was to estimate how much nourishment would be needed in succeeding years and this project needs 38000 cubic yards of sand per year. Presque Isle State Park has 3.5 to 4 million annual visitors who come to savor a relaxing day at one of the few wide and long sandy shores on Lake Erie.

The soothing image of a summer day at Presque Isle makes them return time and again helping generate $920 million in tourist spending in Erie annually.