363 flood insurance claims·$4.7M paid·11 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Grafton County, New Hampshire. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
River flooding and flash flooding from heavy rainfall dominate the flood risks in Grafton County, New Hampshire, backed by 158 flood events, 107 flash flood events with 2 deaths, and 5 tropical storm events over the last 30 years. Heavy precipitation events, such as the July 2024 rainfall when the remnants of Tropical Storm Beryl combined with a Great Lakes low-pressure system, can drop 3 to 5 inches of rain over a 36-hour period onto already saturated ground.
NFIP claim data demonstrates that properties in Zone A experience the most frequent and costly impacts, accounting for 251 claims with an average payout of $20,578 and an average recorded water depth of 7 inches. However, properties outside high-risk zones are also vulnerable; 38 claims were recorded in Zone X with an average payout of $19,823 and an average water depth of 4 inches, 25 claims in Zone X_UNSHADED with an average payout of $9,736 and an average water depth of 5 inches, and 3 claims in Zone X_SHADED with an average payout of $15,048 and an average water depth of 3 inches. An additional 46 claims occurred in Zone UNKNOWN with an average payout of $4,341 and an average water depth of 3 inches.
Homeowners, real estate agents, and journalists should pay the closest attention to properties located within Zone A, while recognizing that properties in Zone X and other unshaded or shaded zones also face recorded flood damage and financial loss.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
10% of Grafton County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
279 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 6 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 2011, with 99 claims and $2.3M paid, the year of Severe Storms and Flooding, Hurricane Irene and Severe Storm.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
120 NOAA storm reports from Grafton County describe what happened, in the words of the forecasters who covered it. Read the New Hampshire flood stories →
40 federal disaster declarations since 1973, 11 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storm And Flooding | Jul 10, 2024 |
| Severe Winter Storm And Flooding | Apr 3, 2024 |
| Severe Storms And Flooding | Jan 9, 2024 |
| Severe Storm And Flooding | Dec 17, 2023 |
| Severe Storms And Flooding | Jul 9, 2023 |
| Severe Storm And Flooding | Dec 22, 2022 |
| Severe Storm And Flooding | Jul 11, 2019 |
| Severe Storm And Flooding | Oct 29, 2017 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
270 since 1996: 107 flash floods and 158 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2024 | — |
| Flash Flood | Jul 30, 2024 | — |
| Flood | Apr 12, 2024 | — |
| Flash Flood | Jul 10, 2024 | — |
| Flash Flood | Jul 6, 2024 | — |
| Flash Flood | Jun 28, 2023 | — |
| Flash Flood | Jun 25, 2023 | — |
| Flash Flood | Jul 18, 2023 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 31, 2024. An area of low pressure supported widespread showers and thunderstorms on July 30th and 31st. Slow storm motions allowed heavy rain to fall over the same area, with high rainfall rates over 2 inches per hour. The most significant flooding occurred over Grafton County where saturated ground conditions and steep terrain supported flash flooding in Piermont.
Flash Flood · Jul 30, 2024. An area of low pressure supported widespread showers and thunderstorms on July 30th and 31st. Slow storm motions allowed heavy rain to fall over the same area, with high rainfall rates over 2 inches per hour. The most significant flooding occurred over Grafton County where saturated ground conditions and steep terrain supported flash flooding in Piermont.
Flood · Apr 12, 2024. A cold front brought widespread soaking rainfall to the area. This rainfall combined with significant snowpack loss and saturated grounds to produce minor to moderate river flooding, with isolated flash flooding across the mountains. Repeated rounds of rain compressed, warmed, and ripened the area snowpack in advance of the heavier rain on Friday the 12th. The combination of rain, strong winds, and high dew points…
Flash Flood · Jul 10, 2024. On July 10th the remnants of Tropical Storm Beryl phased with a low pressure system out of the Great Lakes to bring multiple rounds of heavy rainfall to northern New England, including Maine and New Hampshire. The previous 3 days had brought a swath of heavy rain just north of the White Mountains, saturating the ground and making it ideal for runoff. During the roughly 36 hour period, 3 to as much as 5 inches of r…
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Grafton County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.