Riverine Flood Risk in Washington
All Washington counties ranked by FEMA National Risk Index riverine flood score
Riverine Flood risk — rivers and streams overflowing their banks after heavy rain or snowmelt — is rated for 39 of 39 Washington counties in FEMA's National Risk Index. King County carries the state's highest riverine flood score at 99.5, with $417M in expected annual riverine flood losses.
3 Washington counties are rated High or Very High for riverine flood, and expected annual losses from riverine flood total roughly $1.36B statewide. The full ranking below links to each county's complete 18-hazard risk profile.
County Rankings — Riverine Flood
| # | County | Riverine Flood Score | Rating | Ann. Freq. | Ann. Loss |
|---|---|---|---|---|---|
| 1 | King County | Very High | 0.29 / yr | $417M | |
| 2 | Pierce County | High | 0.11 / yr | $122M | |
| 3 | Snohomish County | High | 0.39 / yr | $112M | |
| 4 | Yakima County | Medium | 1.50 / yr | $44M | |
| 5 | Clark County | Medium | 0.32 / yr | $68M | |
| 6 | Spokane County | Medium | 1.18 / yr | $53M | |
| 7 | Chelan County | Medium | 1.46 / yr | $41M | |
| 8 | Lewis County | Medium | 0.29 / yr | $37M | |
| 9 | Thurston County | Medium | 0.14 / yr | $50M | |
| 10 | Benton County | Medium | 0.39 / yr | $40M | |
| 11 | Okanogan County | Medium | 1.96 / yr | $23M | |
| 12 | Whatcom County | Medium | 0.18 / yr | $40M | |
| 13 | Cowlitz County | Medium | 0.75 / yr | $34M | |
| 14 | Skagit County | Medium | 0.32 / yr | $34M | |
| 15 | Grays Harbor County | Medium | 0.21 / yr | $19M | |
| 16 | Franklin County | Medium | 0.21 / yr | $24M | |
| 17 | Douglas County | Medium | 0.32 / yr | $18M | |
| 18 | Mason County | Medium | 0.18 / yr | $15M | |
| 19 | Kitsap County | Medium | 0.04 / yr | $25M | |
| 20 | Grant County | Medium | 0.36 / yr | $14M | |
| 21 | Clallam County | Medium | 0.21 / yr | $12M | |
| 22 | Kittitas County | Medium | 0.61 / yr | $16M | |
| 23 | Stevens County | Low | 0.64 / yr | $11M | |
| 24 | Klickitat County | Low | 0.25 / yr | $9M | |
| 25 | Walla Walla County | Low | 0.61 / yr | $10M | |
| 26 | Pacific County | Low | 0.36 / yr | $8M | |
| 27 | Whitman County | Low | 0.93 / yr | $10M | |
| 28 | Island County | Low | 0.04 / yr | $8M | |
| 29 | Pend Oreille County | Low | 0.46 / yr | $7M | |
| 30 | Jefferson County | Low | 0.14 / yr | $5M | |
| 31 | Ferry County | Low | 0.82 / yr | $4M | |
| 32 | Lincoln County | Low | 0.43 / yr | $5M | |
| 33 | Skamania County | Low | 0.01 / yr | $8M | |
| 34 | San Juan County | Low | 0.04 / yr | $5M | |
| 35 | Asotin County | Low | 0.39 / yr | $4M | |
| 36 | Adams County | Very Low | 0.14 / yr | $4M | |
| 37 | Columbia County | Very Low | 0.18 / yr | $3M | |
| 38 | Wahkiakum County | Very Low | 1.36 / yr | $2M | |
| 39 | Garfield County | Very Low | 0.14 / yr | $2M |
39 Washington counties with measurable riverine flood risk. See the national riverine flood ranking or all Washington counties by overall risk.
Frequently Asked Questions
Which Washington county has the highest riverine flood risk?
King County has the highest FEMA riverine flood risk score in Washington at 99.5 (Very High), with $417M in expected annual losses and about 0.29 events per year.
How many Washington counties face significant riverine flood risk?
39 Washington counties record measurable riverine flood risk in FEMA's National Risk Index; 3 of them are rated High or Very High.