Public Works

Stormwater Management

Erosion Control Project

Charlotte County placed, via hydraulic dredge and pipeline, approximately 500,000 cubic yards of beach compatible fill material along approximately 2.7 miles of critically eroding coastline on Knight Island and Don Pedro Island. The beach fill areas correspond to two of the County's State-designated Critical Erosion Areas, specifically from Florida Department of Environmental Protection (DEP) monuments R-22 to R-26 and R-29 to R-39. Stump Pass, located immediately updrift of Knight Island, is one designated borrow area. In August 2001, Charlotte County completed the "Stump Pass Inlet Management Study" (IMS) in accordance with DEP guidelines to identify a plan to "mitigate the erosive impact of the inlet". The IMS evaluated the inlet system data and concluded that Stump Pass is a significant cause of erosion on the downdrift beaches of Knights Island and Don Pedro Island. The sediment budget determined that the current bypass quantity is negligible as the majority of sand is being trapped within the Manasota Key spit, updrift of Stump Pass, or within the inlet shoals. County objectives for the project include restoring/enhancing storm protection, natural resource habitats, and recreation beach areas to offset these historical inlet impacts.

Inlet shoaling and spit growth have adversely affected navigation through Stump Pass. The Manasota Key spit continues to elongate, deflecting the inlet channel resulting in beach erosion along the northern interior shoreline of Knight Island. Consistent with the IMS, the secondary purposes of this project is to:

  1. Restore and maintain safe navigation through Stump Pass;
  2. Provide erosion control measures by relocating the channel to its original 1980 location thus reducing the erosional stresses along Knight Island's northern interior shoreline; and
  3. Provide long-term maintenance of the downdrift beaches including transferring sand equal to the bypass quantity of 50,000 cubic yards per year (average) defined in the IMS, adjusting the beach fill areas to accommodate shifts in the nodal zone as the inlet system responds to channel relocation, and mitigating for any adverse impacts resulting from channel relocation.

Phase I of this project was completed in July 2003.