Detailed risk analysis
Interactive Map
Instructions: Use this map to locate the flood-risk map (right).
You can pan and zoom; click to relocate the analysis area (red).
Risk analysis is available only within the blue boundary.
Exceedance
We express "exceedance" (likelihood of flooding) as the expected number of floods per year. Exceedance can be less than 1. Some examples:
- 10 = 10 expected floods per year
- 0.1 = 10% chance of flooding in a given year
- 0.01 = 1% chance of flooding in a given year
| color | flood risk | exceedance (floods/year) | description |
|---|---|---|---|
| frequent flooding | greater than 1 | more than one flood per year | |
| high risk | 0.1 - 1 | worst case: yearly flood | |
| moderate risk | 0.01 - 0.1 | worst case: 10-year flood | |
| low risk | less than 0.01 | worst case: 100-year flood |