Photo: Jerrye & Roy Klotz, MD · CC BY-SA 3.0On FEMA’s figures, Riverdale faces more hazard damage per building than 89% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Riverdale gets a D for hazard risk: higher expected damage per building than 89% of U.S. towns, #429 of 468 in New Jersey. Most of that expected damage is river and rain flooding (95%). Flood insurance has paid 102 claims here since 1979.
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 Riverdale’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Riverdale 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 Riverdale’s grade
River and rain flooding is 95% of the building damage FEMA expects in Riverdale, and Riverdale’s rate of river and rain flooding damage is in the top 4% of U.S. census tracts.
D #429 of 468 in New Jersey; higher expected damage per building than 89% of U.S. towns (21,298).
All of Riverdale’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, Riverdale has more expected damage per building than 92% of New Jersey towns.
In dollars, FEMA expects about $2.9M a year in losses across Riverdale: $2.6M to buildings, the rest to people and crops.
Does Riverdale flood? Yes: 102 flood claims since 1979
Every paid claim on a federal flood insurance policy in Riverdale, from FEMA’s records: 53.2 per 1,000 homes, more than 93% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Irene29 claims · $435K
- The March 2010 nor’easter21 claims · $137K
- The April 2007 nor’easter10 claims · $46K
Riverdale is in FEMA’s Community Rating System (class 8) for its flood-proofing work.
Insurance rates: Morris County.8 federal disasters brought FEMA money to Riverdale
Disasters that paid out in Riverdale itself (aid to households or repair grants to the Borough of Riverdale), newest first, with that year’s flood claims.
- 2021Remnants of Hurricane Ida13 households applied for aid$3K aid approved
- 2020Tropical Storm Isaias$25K to the Borough of Riverdale for repairs
- 2018Severe Winter Storm and Snowstorm$19K to the Borough of Riverdale for repairs
- 2012Hurricane Sandy15 households applied for aid$44K to the Borough of Riverdale for repairs
- 2011Hurricane Irene39 households applied for aid$111K aid approved$36K to the Borough of Riverdale for repairs29 flood claims paid for it, $435K
- 2010Severe Storms and Flooding18 households applied for aid$11K aid approved$24K to the Borough of Riverdale for repairs21 flood claims paid that year
Show all 8
- 2007Severe Storms and Inland and Coastal Flooding2 households applied for aid$2K aid approved10 flood claims paid that year
- 1999Hurricane Floyd Major Disaster Declarations$6K to the Borough of Riverdale for repairs3 flood claims paid for it, $6K
Morris County has had 25 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 Riverdale after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Riverdale archive →Riverdale and its neighbors
Riverdale is 4th of the 6 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 |
|---|---|---|---|
| Kinnelon | C+more damage than 57% | river and rain flooding | 2 |
| Butler | C−more damage than 78% | river and rain flooding | 29 |
| Pequannock Township | C−more damage than 85% | river and rain flooding | 2,037 |
| Riverdale | Dmore damage than 89% | river and rain flooding | 102 |
| Bloomingdale | Dmore damage than 92% | river and rain flooding | 68 |
| Pompton Lakes | D−more damage than 96% | river and rain flooding | 2,301 |
| Pompton Plains | — | 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 Riverdale 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.
- Riverdale residents get 10% off flood insurance.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Riverdale
Is Riverdale at risk for natural disasters?
On FEMA’s National Risk Index, Riverdale has higher expected damage per building than 89% of U.S. towns: D for hazard risk, #429 of 468 in New Jersey. Most of the expected damage is river and rain flooding (95%). 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 Riverdale flood?
Flood insurance has paid 102 claims in Riverdale since 1979, $885K in all, or 53.2 per 1,000 homes, more than 93% of U.S. towns with a flood insurance record. 19 properties have flooded more than once. The most claims came from Hurricane Irene (29).
Is Riverdale 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 Morris County, 1.4% of all homes carry federal flood insurance.
How much is flood insurance in Riverdale?
Riverdale is in FEMA’s Community Rating System (class 8), which takes 10% off federal flood insurance policies for its flood-proofing work. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Riverdale?
By FEMA money that reached Riverdale, Hurricane Irene (2011): 39 households applied for aid, $111K approved, and $36K to the Borough of Riverdale for repairs. By flood claims, Hurricane Irene: 29 paid, $435K.
Is Riverdale at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (95%), and Riverdale’s rate for it is in the top 4% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Riverdale.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Riverdale’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.