Boise, Idaho Flood Zones
Boise faces flooding from the Boise River, particularly during heavy snowmelt years when reservoir storage is insufficient. Urban growth in the foothills has increased flash flood and debris flow risks during intense rainfall.
FEMA Flood Risk Profile: Ada County
Based on FEMA's National Risk Index, which evaluates flood risk at the county level using historical loss data, exposure, and vulnerability.
Inland Flood Risk
Relatively ModerateEst. annual loss: $63.0M
Source: FEMA National Risk Index, county-level assessment. Individual property risk may vary.
Federal Flood Disaster History: Ada County
Ada County has been included in 3 federal flood-related disaster declarations.
These declarations affected communities across Ada County, including Boise.
Source: OpenFEMA Disaster Declarations Summaries API. Data sourced February 2026.
NFIP Flood Insurance Claims: Ada County
Properties in Ada County have filed 131 NFIP flood insurance claims totaling $499K in payouts since 1978. The average claim payout is $4K.
Highest-Claim Years
2017
37 claims - $268K
1997
11 claims - $64K
1992
8 claims - $3K
Claims by Flood Zone
Zone X
66
Zone AE
35
Zone A
10
Zone AO
6
Zone AOB
1
Source: OpenFEMA NFIP Claims API. Data sourced February 2026.
Common Flood Zones in Boise
Properties in Boise, ID are commonly designated in these FEMA flood zones:
What Your Flood Zone Means in Boise
Boise faces multiple inland flood threats, including riverine flooding from nearby waterways and flash flooding from intense rainfall overwhelming urban drainage systems. Properties near river corridors face the highest risk, but stormwater backup can affect neighborhoods well outside the mapped floodplain. The most common FEMA flood zone designations in Boise are Zone AE, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $63.0M.
With both riverine and urban stormwater flood risk, insurance costs in Boise depend heavily on a property's elevation relative to nearby waterways and the local drainage infrastructure. FEMA's Risk Rating 2.0 prices in multiple inland flood sources rather than relying on the flood zone line alone. If your property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance.
Flood zone boundaries in Boise can shift when FEMA updates its Flood Insurance Studies or when upstream development changes how water moves through the watershed. New stormwater infrastructure or dam modifications can also trigger map revisions. Use our free lookup tool to check the current flood zone for any Boise address.
Flood Insurance Discount: Boise
Boise participates in FEMA's Community Rating System (CRS), a voluntary program that rewards communities for flood mitigation efforts beyond minimum NFIP requirements. Residents in the Special Flood Hazard Area may qualify for reduced flood insurance premiums.
CRS Class
Class 7
SFHA Premium Discount
15% off
CRS classes range from 1 (best) to 10 (no discount). Boise's Class 7 rating means NFIP policyholders in the SFHA can receive up to a 15% discount on their flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Source: FEMA Community Rating System, October 2025. Discounts apply to NFIP policies only.
Check Your Boise Address
Enter any Boise, ID address to instantly see its FEMA flood zone, risk level, and whether flood insurance is required.
Free Flood Zone LookupBoise, ID Flood Zone FAQ
What flood zones are in Boise, ID?
The most common FEMA flood zones in Boise are Zone AE, Zone X. Properties in these high-risk zones (SFHA) may require flood insurance with a federally regulated or government-backed mortgage.
Is flood insurance required in Boise?
If your Boise property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance. Properties in Zone X are not federally required to carry flood insurance, though coverage is still recommended since about 25% of all NFIP flood claims come from Zone X properties.
How do I check my flood zone in Boise?
Enter your Boise address in the search tool above for an instant flood zone determination. Results include your FEMA flood zone, SFHA status, base flood elevation (if available), and FIRM panel information, pulled directly from FEMA's National Flood Hazard Layer.
Does Boise offer flood insurance discounts?
Yes. Boise participates in FEMA's Community Rating System (CRS) with a Class 7 rating, qualifying residents in the Special Flood Hazard Area for up to a 15% discount on NFIP flood insurance premiums. Properties outside the SFHA may receive a 5% discount.
Has Boise experienced major flooding events?
Ada County, where Boise is located, has been part of 3 federal disaster declarations for flooding, hurricanes, or severe storms. The most recent was Flooding in 2017. Federal disaster declarations are issued when flooding overwhelms local resources and triggers FEMA assistance programs.
How many flood insurance claims have been filed in Boise?
Ada County has recorded 131 NFIP flood insurance claims totaling $499K in payouts since 1978. The year with the most claims was 2017, with 37 claims and $268K in payouts. These figures cover all NFIP claims in the county, including Boise.
Sources
This page summarizes information from FEMA and other official resources in plain language. For full technical details, see the links below.
- FEMA National Flood Hazard LayerDirect Source
The NFHL is the source of all flood zone data shown on this page.
- FEMA Map Service Center — Search by AddressDirect Source
Look up any address to view FIRM panels, FIS reports, and LOMCs.
- NFHL Data and Map StatusTopic Page
View NFHL coverage and data freshness by state and community.
- FEMA National Risk Index — Data ResourcesDirect Source
County-level risk scores for inland flooding, coastal flooding, and hurricane used in the Flood Risk Profile.
- OpenFEMA Disaster Declarations Summaries API v2Direct Source
Federal disaster declarations filtered for flood-related incident types (Flood, Hurricane, Severe Storm, Coastal Storm).
- OpenFEMA FIMA NFIP Claims API v2Direct Source
Historical NFIP flood insurance claims since 1978, aggregated by county and state. Includes claim counts, payouts, and flood zone breakdowns.
Sources last verified: February 2026