By Jonathan Merwin, Founder and CEO, Licensed Insurance Advisor
New Castle is a town made of islands, with about 7.5 miles of coastline wrapped around less than a square mile of land. Its 2022 hazard plan says that shoreline is exposed to storm surge, to groundwater flooding and to heavy rain, and that floods could limit access on and off the island (New Castle hazard plan, 2022). Route 1B, crossing a causeway and bridges, is the only road in.
Our office is on Islington Street in Portsmouth, just across the back channel. Portsmouth Atlantic Insurance is independent and family-owned, has worked with Seacoast homeowners since 2005, and checks 40+ carriers for the homeowners policy before matching flood coverage to it. Phone (603) 431-4020, or write to insure@portsmouthatlanticins.com.
Key takeaways
- New Castle had 42 NFIP policies at the time of its 2022 plan, with five paid losses and no repetitive losses.
- The town’s maps show VE, AE and X zones. Its current maps and flood study are dated January 29, 2021.
- River Road, the Route 1B causeway and Pit Lane at Route 1B flood most often.
- NFIP limits of $250,000 and $100,000 are often too low for New Castle homes. Private or excess flood can add more.
- About one home in three in New Castle was built before 1940.
What New Castle’s maps show
New Castle has three main flood zones. VE zones face the open water, where the 100-year flood comes with storm waves. AE zones flood in the 100-year event and have a base flood elevation printed on the map. X zones sit outside that line (hazard plan). The town joined the NFIP on August 5, 1986, and its digital maps and flood study took effect January 29, 2021. Check your address on the FEMA Flood Map Service Center.
Ledge is everywhere on the island, so two neighboring houses can sit at very different heights. The plan counts eight active Letters of Map Amendment, FEMA’s formal finding that a particular building sits above the base flood elevation. If you think your house is high enough, an elevation certificate is the first step.
Where the water comes up
| Location | What the town reports |
|---|---|
| River Road and the sewer lift station | Frequent flooding. The lift station flooded in the March 2–3, 2018 nor’easter. |
| Route 1B causeway | Frequent flooding, and one of the two access points the plan calls at risk. |
| New Castle/Rye Bridge (Wentworth Bridge) | The southern access point, also at risk of flooding. |
| Pit Lane at Route 1B | Frequent flooding. A regional road study cited in the master plan ranks NH 1B near Pit Lane among the higher Seacoast priorities. |
The town’s 2024 master plan adds that the generator platforms at the Steamboat Lane and River Road pump stations are being raised two feet, which should hold until about 2050 (New Castle Master Plan 2024). It also notes that many homes still use private septic systems, and that groundwater rising with the sea may push the town to extend sewer service along the south side of Route 1B, from Main Street to Wild Rose Lane.
Old houses and high rebuild costs
Census estimates for 2020–2024 count about 149 of New Castle’s 466 housing units as built before 1940, close to one in three, against about one in five statewide (Census B25034). The master plan explains that the old wharves and commercial buildings became modest homes on small lots, mostly in the Historic District, while the Wentworth redevelopment of the 1990s added about 107 homes on quarter-acre lots.
Both kinds of houses tend to cost much more to rebuild than the NFIP will pay. Historic homes add another question: whether the flood policy and the homeowners policy will pay to repair to the original materials and detail. We review both policies together so the answers line up.
NFIP, private flood and excess flood
For a New Castle home, flood coverage usually comes in one of three shapes:
- NFIP alone. Federal limits cap the structure at a quarter million dollars and belongings at a hundred thousand. That fits smaller homes and condos, and it is the base many lenders ask for.
- Private flood instead. Higher limits, and sometimes additional living expense, which the NFIP leaves out. Underwriting depends on elevation and distance to the water.
- Excess flood above the NFIP. The NFIP policy stays in place and a second policy picks up where its limits end. This works well for a large house that already has a federal policy.
We write new NFIP policies through Selective and quote private and excess flood from Aon Edge, Flow Flood, Neptune, CatCoverage, Beyond Floods and TFIA. FloodSmart lists what the federal policy covers and what it leaves out, including temporary housing (FloodSmart). Expect a waiting period on a new policy, usually 30 days for the NFIP.
Wind, water and the island
In a nor’easter or hurricane, the homeowners carrier handles what the wind breaks, and island properties commonly carry their own wind or named-storm deductible. Storm surge and waves pushing water into the house belong to the flood policy. Water from a backed-up drain is a third coverage again. Because the causeway can close, seasonal owners should also arrange for someone to check the house after a storm, since prompt reporting and mitigation matter on any claim.
More on New Castle: New Castle high-value home insurance and the New Castle insurance agency page. Nearby: Portsmouth flood insurance. Our New Hampshire coastal home insurance page explains the wind side, and high-value homes in Rye, New Castle and Hampton covers the larger houses.
Ask for a New Castle flood quote
Describe the house for us and we will compare federal, private and excess flood options in one summary. There is no broker charge: we don’t charge any fees. Our 1,000+ Google reviews and over 2,000 testimonials come largely from Seacoast families, and our BBB rating is A+. Most quotes, about 90% of them, are ready inside 24 hours. Request a quote. There’s no obligation to buy.
The quote form is directly below. Phones ((603) 431-4020) are answered from 9 to 5 Monday through Thursday and from 8 to 4 Friday, Eastern time, and insure@portsmouthatlanticins.com reaches us any day.
Frequently asked questions
Does New Castle have many flood claims?
Very few so far. The town’s 2022 hazard plan reports 42 NFIP policies, 11 claims made since 1975, five paid losses and no repetitive losses (New Castle Hazard Mitigation Plan Update 2022). A short claims history on a rocky island does not mean low exposure, especially for houses close to the water.
Why would a New Castle home need private or excess flood?
The NFIP stops at $250,000 for a home’s structure and $100,000 for its contents. Many New Castle houses would cost far more than that to rebuild, so owners either buy a private flood policy with higher limits or add an excess flood layer above the NFIP policy.
What is a Letter of Map Amendment?
A LOMA is FEMA’s official finding that a specific building or lot sits above the base flood elevation, even though the map shows it inside the high-risk zone. The plan notes eight active Letters of Map Amendment in New Castle. A LOMA can remove a lender’s flood requirement, though the owner may still choose to keep coverage.
Which parts of New Castle flood most often?
The 2022 plan names River Road and its sewer lift station, the Route 1B causeway, and Pit Lane at Route 1B. During the March 2018 nor’easter, the town avoided major road damage, but the River Road lift station flooded.
What happens if the causeway floods?
Route 1B is the only road on and off the island, according to the 2024 master plan. Flood insurance covers water damage to your building and belongings, not the inconvenience of a closed road, but owners of seasonal homes should plan for how the house will be checked when access is cut.
What do you need to quote flood coverage for my New Castle house?
The address, an elevation certificate or LOMA if you have one, the foundation and basement details, the year built, a rough idea of rebuild cost and any earlier claims. Start with the form on this page or ring (603) 431-4020.
Sources
- Town of New Castle, Hazard Mitigation Plan Update 2022
- Town of New Castle Master Plan, 2024
- Census Bureau ACS five-year estimates (2020–2024), year built, New Castle (B25034)
- FloodSmart: flood policy coverage
- FEMA’s flood map viewer (Map Service Center)
Written as general background for New Castle owners. Nothing here is a quote or legal advice; the wording of your own policy settles what is covered. FEMA maps, town plans and the numbers quoted above get revised, so give us a ring at (603) 431-4020 about a particular house.