Rt-1B Causeway

** Please See & Click the Video Below at the Bottom
Rt 1B Causeway
December 23, 2023


A NH Department of Transportation (NHDOT) report indicates that sea-level rise projections by the year 2050 will make the Rt-1B Causeway, a state highway and one of only 2 access and egress routes for the seacoast island of New Castle to the mainland, impassable and unusable and there are no scheduled state plans for any corrective action.

This is not acceptable to the 1,000 residents of the Town of New Castle.

NHDOT presented an engineering firm's "Draft Feasibility Report" (State Project 29614) of the impacts of sea-level rise on the Rt-1B Causeway that connects the Town of New Castle with the City of Portsmouth. The sea-level rise projections, at a rate of approximately 1 inch per year, would make this major route for vehicles, cyclists and pedestrians, unusable by the year 2050 and perhaps sooner, depending on the severity of coastal storms.

While the engineering firm's report provided 5 alternative corrective actions, with costs, to raise the Causeway, none were identified for implementation in the current NHDOT 10-year plan or the following 10-year plan.

The Rt-1B Causeway is important not just for vehicles, cyclists and pedestrians but it is also a highly-traveled scenic route and, more importantly, the major route for safety concerns ie: mutual fire and police aid from Portsmouth as well as the route for evacuation in the event of a Seabrook Reactor incident or other emergency condition that would require evacuation of, or emergency service to, the island.

The importance of scheduled Causeway improvements in a NHDOT 10-year plan was dramatically brought to the Town's attention on Friday, December 23rd when a coastal Nor-Easter slammed the seacoast (see below) which caused major flooding, temporary closure of the Causeway and limited access to low-lying areas of Rt-1B. Additionally, significant wave action caused the undermining of several areas along the Causeway that could result in a highway washout if not treated.

The Town of New Castle is prepared to recommend one of the 5 corrective actions but there must be an accommodation for this step in a current NHDOT 10-year plan.

The Town requests immediate attention to this issue and Town officials are available for discussion leading to Rt-1B Causeway improvements.

New Castle Town Actions

Of the five alternative corrective actions for causeway improvements, the Town chose Alternative #4 which raises the Causeway 3 feet and widens it for pedestrian and cycle traffic and raises the low spots on Rt-1B by 2.5 feet. The preliminary cost estimate for this corrective action is $5.2M.

Representatives of the Town initiated discussions with local and state government officials with the goal of having the Causeway assigned to a current NHDOT 10-year plan. Communications with state             congressional representatives led to a meeting with the Commissioner of NHDOT and the Chair of the New Castle Select Board.

NHDOT Update

NHDOT Commissioner William Cass indicated that the best way to move the Causeway project on to a priority list was for all Causeway stake holders (New Castleresidents and others) to send emails, letters and other means of communications to the appropriate Governor's Executive Council member, local state senators and representatives, Rockingham Planning Commission executives and abutting town Select Boards and City Councils.

Governor's Executive Councilor Janet Stevens

Governor's Executive Councilor Janet Stevens was the first to respond with an offer to help in any way that she could. Councilor Stevens proactive involvement in the Causeway program opened up possibilities for the re-prioritization of the Causeway to be included in an early upcoming 10-year plan.

The NHDOT Project Development Director noted that “a lot of positives regarding the data/findings came from the feasibility study”. The study clearly defined project goals, project scope, preliminary cost estimate, build recommendation of 3’ increase on 1B Causeway with 2’.5” increase in three other low-lying areas on 1B, meets the needs of mitigating and avoiding impacts to the 1B Causeway due to sea level and storm surges. NHDOT Commissioner William Cass has stated that the “feasibility study is sufficient for initial draft of TYP (ten-year plan”.

Councilor Stevens efforts were rewarded with the Governor's support of moving the Causeway into the 10-year plan.

Next Steps

While much effort has been devoted to this program, there is still much to do. A key element in keeping the Causeway topical in the minds of those who can make this happen is the Governor's Advisory Commission Intermodal Transportation (GACIT) hearings. These hearings will occur in September and October 2023 in Exeter, NH. Dates, times and specific locations will be provided in the next several months.

It is important for New Castle residents to attend these hearings and testify on the value and safety of Causeway improvements for all New Castle residents.

In February 2023, the "Feasibility Report" from engineering firm, McFarland Johnson was approved.

Updates from Councilor Stevens

Councilor Stevens provides regular updates of her projects and programs which will be available here.

The Town wishes to thank all those who have taken an active interest in the Causeway project and asks that you continue that interest and those actions. The work is not done yet!       

Please Click on the Link Below to View Storm Impacts to the RT. 1B Causeway :