Scoping of Dredge Material Islands and Wetlands for Green Infrastructure Resiliency Projects Along the Connecticut Shoreline in Fairfield and New Haven Counties

Project Summary

Studies show that wetland habitats act as natural buffers against waves and powerful storm surges. With funds from the Connecticut Department of Housing CDBG-DR Sandy Recovery Program, this project determined the feasibility of the process of utilizing dredge materials to restore, create, or enhance tidal marshes to decrease erosion and improve drainage. This project produced a feasibility assessment, design parameters, a regulatory framework, and an evaluation of the impact of the creation of wetlands on the health and safety of vulnerable populations.

Products

Beneficial Use of Dredge Material

Appendix A - Ecosystem Services

Appendix B - History Marsh Management

Appendix C - CaseStudyAppendixfinal

Appendix D - Policy Framework Dredge Wetands

Appendix E - September Workshop Proceedings_Report

Appendix F - Users Guide

Appendix G - Coastal Resilience and Wave Attenuation

Appendix H - Mosquitos Other Pests

Project Description

The highly developed shorelines of Fairfield and New Haven Counties were among the most heavily impacted by Superstorm Sandy (2012). If these counties had more marshland along its coast, it is possible that some of those impacts may have been avoided as studies show that wetland habitats act as natural buffers against waves and powerful storm surges. With funds from the Connecticut Department of Housing CDBG-DR Sandy Recovery Program, this project determined the feasibility of utilizing dredge materials to construct artificial marshes and wetland islands to decrease erosion and improve drainage, which would effectively increase an area’s resilience to the impacts of sea level rise and severe storms. Dually, the utilization of dredge materials could provide a productive end-use of a product which is typically disposed of at a cost.

Creating marshes along shorelines also has the potential to enhance the sustainability of communities by providing public access to natural amenities and maintaining or increasing ecosystem services. This project focused on a feasibility assessment, design parameters, a regulatory framework, and an evaluation of the impact of the creation of wetlands on the health and safety of vulnerable populations.

The project team completed a literature review and conducted research on the physical and engineering features required to establish artificial wetlands and wetland islands using the most cost-effective dredge materials. Through this process the team determined design parameters, like wetland gradient, site exposure, and soil type, necessary for on-the-ground construction. The team met with state and federal regulatory agencies and review existing policies to outline the regulatory framework, including permitting guidance, underpinning this type of project in Connecticut. This helped determine the regulatory bounds of this approach. Recognizing that there may be health and safety impacts of developing wetlands and islands on vulnerable populations, the research team also evaluated possible project impacts. This evaluation included outreach to stakeholders (including members of housing, public health, and emergency preparedness and response groups) to determine criteria and guidance for working with these groups on a potential artificial wetland creation projects in the future.

Now that the project is complete, the assessment, design parameters, regulatory framework, and evaluation criteria for the impacts on vulnerable populations has formed guidance for the state and municipalities for future projects.

Completion date: September 2018


Researchers and Staff Supported on Project

Jennifer O’Donnell, UConn Department of Marine Sciences

Jamie Vaudrey, UConn Department of Marine Sciences

Craig Tobias, UConn Department of Marine Sciences

Carolyn Lin, UConn Department of Communications

Paula Schenck, UConn Health

Rebecca French, UConn CIRCA

Kimberly Bradley, UConn CIRCA

Dredge Project cover photo

“What We Do” Areas

 

 

This project is a part of the following topical areas:

 

Critical Infrastructure

Living Shorelines

Policy and Planning