Photo: User:Ekem · Public domainOn FEMA’s figures, Green Brook Township faces more hazard damage per building than 85% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Green Brook Township gets a C− for hazard risk: higher expected damage per building than 85% of U.S. towns, #403 of 468 in New Jersey. Most of that expected damage is river and rain flooding (92%). Flood insurance has paid 268 claims here since 1981.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What stands out about Green Brook Township’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Green Brook Township faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Green Brook Township’s grade
River and rain flooding is 92% of the building damage FEMA expects in Green Brook Township, and Green Brook Township’s rate of river and rain flooding damage is in the top 8% of U.S. census tracts.
C− #403 of 468 in New Jersey; higher expected damage per building than 85% of U.S. towns (21,298).
All of Green Brook Township’s residents live in one census tract; the figures are that tract’s.
The typical New Jersey town has higher expected damage than 56% of U.S. towns; within the state, Green Brook Township has more expected damage per building than 86% of New Jersey towns.
In dollars, FEMA expects about $5.6M a year in losses across Green Brook Township: $4.7M to buildings, the rest to people and crops.
Does Green Brook Township flood? Yes: 268 flood claims since 1981
Every paid claim on a federal flood insurance policy in Green Brook Township, from FEMA’s records: 110.2 per 1,000 homes, more than 97% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Floyd49 claims · $932K
- Hurricane Irene45 claims · $1.1M
- The 2025 July NYC Metro Area Flooding45 claims · $3.2M
Green Brook Township isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Somerset County.9 federal disasters brought FEMA money to Green Brook Township
Disasters that paid out in Green Brook Township itself (aid to households or repair grants to Green Brook Township), newest first, with that year’s flood claims.
- 2021Remnants of Hurricane Ida110 households applied for aid$522K aid approved$616K to Green Brook Township for repairs39 flood claims paid for it, $1.8M
- 2018Severe Winter Storm and Snowstorm$381K to Green Brook Township for repairs
- 2016Severe Winter Storm and Snowstorm$30K to Green Brook Township for repairs
- 2012Hurricane Sandy147 households applied for aid$25K aid approved$560K to Green Brook Township for repairs
- 2011Hurricane Irene128 households applied for aid$280K aid approved$225K to Green Brook Township for repairs45 flood claims paid for it, $1.1M
- 2010Severe Winter Storm and Snowstorm$17K to Green Brook Township for repairs
Show all 9
- 2010Severe Storms and Flooding19 households applied for aid$57K aid approved$240K to Green Brook Township for repairs
- 2007Severe Storms and Inland and Coastal Flooding6 households applied for aid$3K aid approved17 flood claims paid that year
- 1999Hurricane Floyd Major Disaster Declarations$72K to Green Brook Township for repairs49 flood claims paid for it, $932K
Somerset County has had 22 natural disasters declared by the President since 1953, most often severe storms, then hurricanes and tropical storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees; the 2001 World Trade Center declarations.
Old photos of Green Brook Township after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Green Brook Township archive →Green Brook Township and its neighbors
Green Brook Township is 4th of the 8 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Warren Township | B−less damage than 50% | river and rain flooding | 40 |
| Bridgewater Township | C+more damage than 59% | river and rain flooding | 225 |
| Watchung | C−more damage than 83% | river and rain flooding | 24 |
| Green Brook Township | C−more damage than 85% | river and rain flooding | 268 |
| Dunellen | Dmore damage than 89% | river and rain flooding | 362 |
| Plainfield | Dmore damage than 90% | river and rain flooding | 961 |
| North Plainfield | Dmore damage than 91% | river and rain flooding | 523 |
| Middlesex | Dmore damage than 91% | river and rain flooding | 977 |
| Martinsville | — | a Census area inside a town; graded with the town | |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what Green Brook Township faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Green Brook Township
Is Green Brook Township at risk for natural disasters?
On FEMA’s National Risk Index, Green Brook Township has higher expected damage per building than 85% of U.S. towns: C− for hazard risk, #403 of 468 in New Jersey. Most of the expected damage is river and rain flooding (92%). The figures are for the one census tract the town shares with its neighbors. This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Green Brook Township flood?
Flood insurance has paid 268 claims in Green Brook Township since 1981, $8.6M in all, or 110.2 per 1,000 homes, more than 97% of U.S. towns with a flood insurance record. The most claims came from Hurricane Floyd (49).
Is Green Brook Township in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Somerset County, 53% of homes in mapped flood zones carry federal flood insurance, and 1.4% of all homes do.
How much is flood insurance in Green Brook Township?
FEMA’s Community Rating System list shows no discount for Green Brook Township’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Green Brook Township?
By FEMA money that reached Green Brook Township, Remnants of Hurricane Ida (2021): 110 households applied for aid, $522K approved, and $616K to Green Brook Township for repairs. By flood claims, Hurricane Floyd: 49 paid, $932K.
Is Green Brook Township at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (92%), and Green Brook Township’s rate for it is in the top 8% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Green Brook Township.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Green Brook Township’s residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.