Fairfield – Benefit Cost Analysis for Climate Resilience

Project Summary

The Town of Fairfield, south of the I-95 corridor, was originally marshy land, that has been largely filled in and developed over time. Today, roughly 3000 structures sit in the Town’s flood plain, including many town buildings and historical sites, 5 churches and three schools, as well as roughly 15 % of the town's residential housing.

In 2019, The Army Corp of Engineers (USACE) conducted a study that resulted in a multi section plan to protect the Fairfield shoreline. They assessed the risk as hundreds of millions of dollars in total estimated damages and a potential loss of life (referencing the 1938. 1954 and 1955 storm event loss of life) based on a 1% Annual Exceedence Probability (AEP) flood. Their plan, a plan that would protect most of the town infrastructure and residences from high flood events, had a projected cost of $546 million and while it had a positive cost benefit ratio of 1.7, it ultimately was not expected to meet the cost benefit thresholds to be approved for federal funding. The cost was considered too high for the town to proceed on its own.

The Town has assessed the USACE plan and identified “critical” sections that, if implemented, have the potential to mitigate the majority of the damages and impact from major storm events. The Town is hoping to investigate lower cost alternatives to produce a more competitive BCR and then would be able to propose to move those projects forward. The town would expect to apply for individual grants for each of these sections as grant funding becomes available. In order to do that, the town needs to update the USACE costs (USACE had provided “Project Costs” in 2019 dollars) and to perform a Benefit Cost Analysis, BCA.

CIRCA's MRGP grant in the amount of $30,000 covers updated costs and a BCA for two to three of the sections of the town plan to confirm these are highly beneficial projects.

Product

Available May, 2023

Project Description

The USACE plan and Fairfield comprehensive resiliency projects have identified project segment areas. The first three priorities include:

First priority – update the USACE costs to provide for 2 “T- wall” sections of the plan from Jennings Beach, past the marina section and to create a 7 ft “T-wall” section that will tie into Ash Creek Open Space. The town would like to investigate more cost effective mitigation such as earthen berms/dikes and utilizing tidegate(s) instead of pump station. A core part of this will be determining the BCA for this part of the plan in order to move towards a grant ready project that would involve detailed design and eventual construction.

Second Priority – If funds permit, the Town would propose to work with a consultant to update the USACE costs for the Salt Meadow Road “T – wall” run. Cost saving and effective alternatives would also be investigated. A core part of this will be determining a BCA for this section in order to move towards a grant ready project for more detailed design and eventual construction.

Third Priority – The Town of Fairfield has shovel ready plans (completed final design plans) for a combined self regulating tidegates, culvert and sewer siphon project. Unfortunately so far, the complex nature of the project has had limited grant opportunities. By developing a BCR, the Town could be able to determine if project meets various grant criteria that includes environmental benefits.

Although the Town feels all three priorities are beneficial, projects have been identified as Priority One, Two and Three. By obtaining the Benefit Cost Analysis, the Town can further prioritize its project pipeline efforts and identify relevant funding programs for those segments. The Town hopes to continue to make significant progress in improving resiliency in targeted or beneficial areas.

Fairfield priority BCA areas

Fairfield priority BCA areas

Topic Areas

This project is a part of the following topical areas:

Coastal Flooding & Waves