Colchester to Southeast Shoal

Colchester to Southeast Shoal Littoral Cell

The Colchester to Southeast Shoal Littoral Cell Investigation was commissioned by the Essex Region Conservation Authority with funding from Parks Canada and the Ontario Ministry of Natural Resources, and undertaken by W.F. Baird and Associates. The study is a proactive investigation to look at sand supply and sand movement along the shoreline and the impacts of shoreline protection and harbours. The investigation was initiated to understand the potential for sand exchange between the east and west sides of Point Pelee National Park and as a result of shoreline erosion concerns from landowners in the area.

Historically, the recession of the bluffs, beaches and the lake bottom provided a continuous supply of new sand and gravel to the Lake Erie shoreline located between Colchester and the tip of Point Pelee National Park. For thousands of years, sand and gravel eroded from the shoreline and was transported in an east then south direction towards the National Park. This material, combined with the sediment transported in a southerly direction along the east side of the peninsula, built the long trapezoid shaped pile of submerged sand known as the southeast shoal.

Today, approximately 87% of the shoreline is armoured with shoreline protection structures between Colchester and Point Pelee National Park. These shore protection structures have reduced the supply of new sand and gravel. In addition, it has been determined that the natural transport of sediment along this reach of shoreline has been disrupted by the construction of harbours and sediment management practices at these sites over the past 100 years. Collectively, the harbours have trapped or permanently removed approximately 4.3 million cubic metres of sand and gravel.

This decreased supply of sand and gravel has resulted in lakebed erosion and the loss of beaches within the study area. In addition, the overall reduction of sediment supply from both the east and west sides of Point Pelee has contributed to the reduced size of the national park in the last several decades. It is recommended that a sediment management plan be developed for this reach of shoreline to slow or stop these adverse trends.

ERCA and its partners want to ensure that landowners were well aware of the information so that all parties can work together to be proactive in trying to address these erosion problems. It is critical that solutions are investigated before the problems become as serious as the conditions on the east side of the peninsula.

A working group that includes representatives from the three affected municipalities, Federal and Provincial agencies and organizations associated with the harbours has been established to jointly determine a course of action. Future investigations could consider the potential for sand bypassing at harbours and artificial sand nourishment along this shoreline.

For a full copy of the report, click here.