Boulder Canyon’s biggest natural hazard is inland flooding
Most of the natural-hazard damage FEMA expects in Boulder Canyon comes from inland flooding, and overall the risk is very high for a U.S. community.
What stands out about Boulder Canyon’s weather risks
Read from FEMA’s records below. The page puts what stands out first.
Does Boulder Canyon flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Boulder Canyon. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Boulder Canyon isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Lawrence County.How exposed is Boulder Canyon?
FEMA expects yearly storm and flood damage to homes and buildings here to be higher than in 88% of U.S. communities, mostly from inland flooding.
Rated higher than 1,365 of the 1,384 South Dakota towns we cover.
Boulder Canyon is smaller than a census tract, so it shares the figures of the tract around its center.
What Boulder Canyon faces
Each hazard’s share of the damage FEMA expects here, and how it compares with the rest of the country.
Inland flooding
Wildfire
Federal disasters declared here
None of the disasters declared for Lawrence County shows FEMA aid or repair money reaching Boulder Canyon itself in FEMA’s records.
Lawrence County has had 15 natural disasters declared since 1953, most often floods and severe storms.
Get ready for what Boulder Canyon actually faces
A short kit for its top hazards, 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.
- Clear dead leaves and brush within 5 feet of the house.
- Sign up for local alerts and know two ways out.
- Keep N95 masks for smoky days.
- Keep a shovel, a blanket and snacks in the car.
- Clear snow from furnace and dryer vents.
- Check on older neighbors when the power goes out.
- 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.
Most disasters here begin in May–June
The month each of Lawrence County’s 15 declared disasters began, since 1953.
What these numbers can and can’t tell you
- An average, not a forecast. FEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.
- Compared by rate. “Higher than N%” compares yearly damage as a share of what’s there, so a big city isn’t rated riskier just for having more buildings.
- Money that reached town. Flood claims are matched to Boulder Canyon’s own flood-insurance community; household aid to the registrant’s city; repair grants to Boulder Canyon.
- It follows property value. FEMA’s model weighs damage to buildings, so a place that recently lost many homes can rate lower than it feels.
Storm stories
Memories, warnings and help from neighbors in Boulder Canyon.
Your answer becomes a post in Town Square.
Sources: FEMA National Risk Index (December 2025); 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. Census tracts: U.S. Census Bureau. Preparedness tips: Ready.gov. An average of past damage, not a forecast.