Riverine Flood Risk in Wyoming
All Wyoming 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 23 of 23 Wyoming counties in FEMA's National Risk Index. Natrona County carries the state's highest riverine flood score at 74.7, with $19M in expected annual riverine flood losses.
No Wyoming county reaches the High band for riverine flood, and expected annual losses from riverine flood total roughly $147M 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 | Natrona County | Medium | 0.82 / yr | $19M | |
| 2 | Sheridan County | Medium | 0.71 / yr | $17M | |
| 3 | Laramie County | Low | 2.04 / yr | $13M | |
| 4 | Fremont County | Low | 1.50 / yr | $10M | |
| 5 | Park County | Low | 0.82 / yr | $9M | |
| 6 | Big Horn County | Low | 0.89 / yr | $6M | |
| 7 | Sweetwater County | Low | 0.39 / yr | $8M | |
| 8 | Carbon County | Low | 0.29 / yr | $6M | |
| 9 | Washakie County | Low | 0.50 / yr | $5M | |
| 10 | Albany County | Low | 0.64 / yr | $6M | |
| 11 | Converse County | Low | 0.18 / yr | $5M | |
| 12 | Campbell County | Low | 0.75 / yr | $7M | |
| 13 | Hot Springs County | Low | 0.21 / yr | $4M | |
| 14 | Johnson County | Low | 0.86 / yr | $4M | |
| 15 | Lincoln County | Low | 0.64 / yr | $4M | |
| 16 | Teton County | Very Low | 0.36 / yr | $6M | |
| 17 | Uinta County | Very Low | 0.04 / yr | $5M | |
| 18 | Platte County | Very Low | 0.75 / yr | $3M | |
| 19 | Goshen County | Very Low | 0.86 / yr | $4M | |
| 20 | Sublette County | Very Low | 0.29 / yr | $3M | |
| 21 | Crook County | Very Low | 0.68 / yr | $2M | |
| 22 | Weston County | Very Low | 0.64 / yr | $1M | |
| 23 | Niobrara County | Very Low | 0.18 / yr | $691K |
23 Wyoming counties with measurable riverine flood risk. See the national riverine flood ranking or all Wyoming counties by overall risk.
Frequently Asked Questions
Which Wyoming county has the highest riverine flood risk?
Natrona County has the highest FEMA riverine flood risk score in Wyoming at 74.7 (Medium), with $19M in expected annual losses and about 0.82 events per year.
How many Wyoming counties face significant riverine flood risk?
23 Wyoming counties record measurable riverine flood risk in FEMA's National Risk Index; 0 of them are rated High or Very High.