GC Flood Alerts is a Greasemonkey script that shows flood warning information for England and Wales on the maps page on Geocaching.com. It inserts an icon at the top right of the map which allows you to turn alerts on and off.
The script uses data from the Environment Agency's Live Flood Warning Map and plots it on the geocaching map. Clicking on the flood symbols will show you the description of each warning. The title of each alert links through to the Environment Agency website so you can check you have the latest information.
Floods can be very dangerous. These alerts can only be a guideline to conditions on the ground, which may change very quickly. Use common sense when visiting any area liable to flooding, and follow advice from the Environment Agency and local authorities. For more information about flooding, see the Environment Agency Floods website.
The script requests new data every 15 minutes, and shows you when the data source was last updated by a timestamp in the bottom-right of the screen. Although the data set is also normally updated every 15 minutes, individual alerts are updated much less often. The description of each alert will tell you roughly how long ago it was updated at the point the data set was regenerated.
NB This script only works if you are using Leaflet Maps. You can select Leaflet Maps using the "Set Map Preferences" button at the bottom of the sidebar on the left of the Geocaching Maps.