Sea Level Rise

CIRCA Sea Level Rise Projects & Products

CIRCA’s current research projects in the area of sea level rise are listed on the Sea Level Rise Projects & Products site. There you can find a description of ongoing projects and any products from the project, including tools, reports, data, presentations, etc.

CIRCA local sea level rise projections: ODonnell 2017 Technical Report Executive Summary and Presentation (with audio) and slides only.

Below is a general description of sea level rise impacts.

CIRCA works to enhance coastal resilience to sea level rise in Connecticut. Sea level change is caused by a number of factors summarized in the figure on the right (click to enlarge), but in recent decades ocean warming and ice sheet loss due to global warming have contributed significantly to global sea level rise. Along the east coast, including Connecticut, sea level rise rates are more rapid than the global average rate because of subsidence or sinking of the coastline.

CIRCA Local Sea Level Rise Scenarios for the State of Connecticut

In 2012 NOAA released global sea level rise scenarios that were referenced in Connecticut state statute requiring that sea level rise be considered in state and local plans of conservation and development and natural hazard mitigation plans. That same statute charged UConn CIRCA with updating the scenarios to be local for the state of Connecticut. On October 19, 2017 CIRCA presented the local sea level rise scenarios in a public meeting. On March 27, 2018 CIRCA released the full Draft Report, Sea Level Rise in Connecticut. View the Presentation and Report.

Based on the scenarios CIRCA recommends that Connecticut plan for the upper end of the range of values projected of sea level rise or up to 20 inches (50cm) of sea level rise higher than the national tidal datum in Long Island Sound by 2050 and that it is likely that sea level will continue to rise after that date. The Institute also recommended that the scenarios be updated at least every 10 years to incorporate the best available science and new observations.

Connecticut Legislation

CIRCA's report, Sea Level Rise Projections for the State of Connecticut (below) published in 2018 provides the basis for sea level rise projections in Governor's Bill S.B. 7, which was introduced into the 2018 legislative session and was enacted into law as Public Act 18-82.

Senate Bill No. 7, Public Act No. 18-82

PA 18-82

Substitute Senate Bill No. 9, Public Act No. 18-50

PA 18-50

Final Report

Sea Level Rise and Coastal Flooding and Inundation in Connecticut

Sea level rise has multiple impacts on the Connecticut shoreline, including increased erosion rates, increased frequency of flooding, and coastal inundation. As sea levels rise the shoreline responds and beaches get eroded away and the coastline moves back. Other coastal features, like salt marshes, also migrate landward. With a relative higher sea level, a storm surge or high tide, that would not have been a problem in the past, now results in flooding. Inundation is the permanent drowning of our coastline. In the short-term the increase of 8 inches in sea level that we have already experienced since the mid-1800s is not as noticeable against the daily tides, however if sea level continues to rise at a rapid rate, the shoreline can expect to see somewhere between 1.9 and 6.6 feet of sea level rise by the end of the century based on the CIRCA local sea level rise projections.

Suggested citation for sea level rise graphic:

O’Donnell J., (2017) Sea Level Rise and Coastal Flood Risk in Connecticut. Draft Report to the CT Department of Energy and Environmental Protection


White Papers

Released by CIRCA and UConn's Center for Energy and Environmental Law (CEEL)

Floodplain Building Elevation Standards

Height Restrictions on Elevated Buildings

Oceanfront State Coastal Management Programs

Statutory Adoption of Updated SLR Scenarios

(Credit: CT DEEP)

sea level rise illustration
(Click image to enlarge) The factors that contribute to sea level change, both on land and in the sea. Source: IPCC (2001)