Riverine Flood Risk in Pennsylvania
All Pennsylvania 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 67 of 67 Pennsylvania counties in FEMA's National Risk Index. Philadelphia County carries the state's highest riverine flood score at 99.6, with $266M in expected annual riverine flood losses.
15 Pennsylvania counties are rated High or Very High for riverine flood, and expected annual losses from riverine flood total roughly $2.73B 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 | Philadelphia County | Very High | 5.82 / yr | $266M | |
| 2 | Allegheny County | Very High | 7.32 / yr | $295M | |
| 3 | Montgomery County | High | 5.71 / yr | $193M | |
| 4 | Bucks County | High | 4.43 / yr | $141M | |
| 5 | Lancaster County | High | 3.43 / yr | $111M | |
| 6 | Lehigh County | High | 3.18 / yr | $68M | |
| 7 | Luzerne County | High | 2.46 / yr | $64M | |
| 8 | Berks County | High | 4.82 / yr | $69M | |
| 9 | Dauphin County | High | 2.04 / yr | $75M | |
| 10 | Delaware County | High | 4.64 / yr | $74M | |
| 11 | Chester County | High | 5.46 / yr | $106M | |
| 12 | Lackawanna County | High | 1.68 / yr | $57M | |
| 13 | Westmoreland County | High | 4.82 / yr | $66M | |
| 14 | Northampton County | High | 3.32 / yr | $63M | |
| 15 | York County | High | 3.46 / yr | $69M | |
| 16 | Washington County | Medium | 3.71 / yr | $51M | |
| 17 | Cumberland County | Medium | 2.11 / yr | $50M | |
| 18 | Schuylkill County | Medium | 1.79 / yr | $36M | |
| 19 | Erie County | Medium | 2.14 / yr | $38M | |
| 20 | Fayette County | Medium | 3.54 / yr | $32M | |
| 21 | Lycoming County | Medium | 1.89 / yr | $35M | |
| 22 | Butler County | Medium | 2.46 / yr | $41M | |
| 23 | Northumberland County | Medium | 1.25 / yr | $30M | |
| 24 | Monroe County | Medium | 2.18 / yr | $33M | |
| 25 | Mercer County | Medium | 2.50 / yr | $29M | |
| 26 | Blair County | Medium | 1.54 / yr | $27M | |
| 27 | Crawford County | Medium | 2.36 / yr | $22M | |
| 28 | Beaver County | Medium | 2.68 / yr | $30M | |
| 29 | Bradford County | Medium | 3.25 / yr | $28M | |
| 30 | Cambria County | Medium | 1.29 / yr | $24M | |
| 31 | Armstrong County | Medium | 1.71 / yr | $26M | |
| 32 | Lebanon County | Medium | 1.86 / yr | $27M | |
| 33 | Franklin County | Medium | 1.89 / yr | $26M | |
| 34 | Bedford County | Medium | 1.64 / yr | $21M | |
| 35 | Mifflin County | Medium | 0.50 / yr | $15M | |
| 36 | Lawrence County | Medium | 2.29 / yr | $22M | |
| 37 | Warren County | Medium | 1.04 / yr | $21M | |
| 38 | Centre County | Medium | 1.04 / yr | $19M | |
| 39 | Clearfield County | Medium | 1.36 / yr | $17M | |
| 40 | Somerset County | Medium | 1.79 / yr | $18M | |
| 41 | Tioga County | Medium | 1.32 / yr | $16M | |
| 42 | Pike County | Medium | 0.61 / yr | $18M | |
| 43 | Columbia County | Medium | 1.39 / yr | $20M | |
| 44 | Indiana County | Medium | 1.89 / yr | $14M | |
| 45 | Adams County | Medium | 1.64 / yr | $17M | |
| 46 | Jefferson County | Medium | 1.96 / yr | $11M | |
| 47 | Greene County | Medium | 1.86 / yr | $15M | |
| 48 | Venango County | Medium | 2.32 / yr | $13M | |
| 49 | McKean County | Medium | 1.18 / yr | $13M | |
| 50 | Union County | Low | 1.32 / yr | $11M | |
| 51 | Wayne County | Low | 1.32 / yr | $13M | |
| 52 | Clinton County | Low | 0.86 / yr | $11M | |
| 53 | Snyder County | Low | 1.04 / yr | $11M | |
| 54 | Susquehanna County | Low | 1.71 / yr | $14M | |
| 55 | Perry County | Low | 1.18 / yr | $13M | |
| 56 | Wyoming County | Low | 1.43 / yr | $12M | |
| 57 | Huntingdon County | Low | 1.79 / yr | $12M | |
| 58 | Elk County | Low | 0.43 / yr | $13M | |
| 59 | Carbon County | Low | 1.93 / yr | $12M | |
| 60 | Juniata County | Low | 0.68 / yr | $7M | |
| 61 | Potter County | Low | 0.61 / yr | $6M | |
| 62 | Clarion County | Low | 1.54 / yr | $6M | |
| 63 | Forest County | Low | 0.57 / yr | $4M | |
| 64 | Cameron County | Low | 0.36 / yr | $4M | |
| 65 | Montour County | Low | 0.75 / yr | $4M | |
| 66 | Sullivan County | Low | 1.00 / yr | $4M | |
| 67 | Fulton County | Very Low | 0.61 / yr | $3M |
67 Pennsylvania counties with measurable riverine flood risk. See the national riverine flood ranking or all Pennsylvania counties by overall risk.
Frequently Asked Questions
Which Pennsylvania county has the highest riverine flood risk?
Philadelphia County has the highest FEMA riverine flood risk score in Pennsylvania at 99.6 (Very High), with $266M in expected annual losses and about 5.82 events per year.
How many Pennsylvania counties face significant riverine flood risk?
67 Pennsylvania counties record measurable riverine flood risk in FEMA's National Risk Index; 15 of them are rated High or Very High.