Cumulative Impacts and Coastal Changes

The cumulative impacts of coastal erosion are influenced by a cascade of drivers compounding in space and time that have physical, social, and community ramifications. Risk to coastal communities caused by increasingly intense physical changes threaten people, their livelihoods, and environmental health. Coastal erosion costs the U.S. over $500 million in damages, over $150 million in infrastructure and over 80,000 acres of wetlands every year.  In the Great Lakes, fluctuating water levels and more intense storms have created a physical environment that appears to be consuming the shoreline. Erosion of coastal assets such as bluffs and dunes can be observed at the bottom (toe) up to the top (crest), often nearby human infrastructure, namely people's homes. The current practice to defend against this perceived threat is armoring the shore with conventional building materials, which have been shown to adversely affect neighboring properties. The cumulative impacts of these structures under fluctuating water levels and more intense storm waves have yet to be quantified. Additionally, indirect risks – such as elevated erosion occurring on properties adjacent to coastal structures – associated with coastal bluff erosion have not been comprehensively characterized. Furthermore, the role of local and global decision-makers has not been integrated with an analysis of the physical drivers to coastal erosion. These gaps in knowledge pose social, economic and environmental challenges that fuel community conflict, incur heavy costs, and jeopardize local and regional ecosystems.

A resilient coast tackles these gaps through a transdisciplinary approach of characterizing and responding to the compound risks linked to cumulative coastal erosion. Sustainable shore protection with Nature-Based Coastal Solutions integrated with the human dimension is a missing link in traditional coastal management practice. Southeastern Wisconsin experiences accelerated rates of bluff erosion under historically high-water levels and increased levels of human-development. As bluffs become less stable, the need for comprehensive sustainable shore protection that addresses the cumulative impacts of coastal erosion becomes more pressing.