Detailed Flood Risk Map
Interactive Map
Instructions: Click the interactive map above to relocate the flood-risk map (right). You can also pan and zoom this map.
Explore flood risk (right) with controls below the map. Risk analysis is available only within the blue boundary on the map above.
Exceedance
| color | flood risk | annual flood exceedances (expected floods/year) | description |
|---|---|---|---|
| frequent flooding | greater than 1 | expect more than one flood per year | |
| high risk | 0.1 - 1 | 10% annual chance of flooding to annual flooding | |
| moderate risk | 0.01 - 0.1 | 1% to 10% chance of flooding in a given year | |
| low risk | less than 0.01 | less than 1% chance of flooding in a given year |
We express flood risk as annual flood exceedances, or the number of floods expected per year. Annual exceedances can be less than 1. Some examples:
- 10 annual flood exceedances = expect 10 floods/year
- 1 annual flood exceedance = expect yearly
- 0.1 annual flood exceedances = 10% chance of flooding each year
- 0.01 annual flood exceedances = 1% chance of flooding each year