28 June 2011, 06:00
Figures obtained exclusively by Heart show two thirds of people in the Thames Valley, who live near rivers at risk of flooding, haven't signed up to the alert system.
It means the Environment Agency can't warn people when rivers near their homes are rising.
Lots of people are automatically signed up, but the Environment Agency says if they don't register for the full service, they don't know if their contact details are correct and they'll get general warnings instead of targeted ones for their area.
Despite all the warm weather we're having, Flood Warning Duty Officer Sarah Hale says it's really important to sign up to Floodline; "Lots of dry weather means that the ground is very dry itself. It means if we do get rainfall it's very hard to soak into the ground. Lots of people will remember the 2007 floods, they did happen after a dry period."
Across Berkshire, Oxfordshire and Buckinghamshire more than 65,000 people are at risk, but only 20,000 have signed up.
The Environment Agency operates a four tier warning system:
* Flood Alert - Flooding is possible. Be prepared.
* Flood Warning - Flooding is expected. Immediate action is required.
* Severe Flood Warning - Severe flooding. Danger to life.
* Warnings no longer in force - Warnings have been removed in the last 24 hours.
You can find out if your home, business or place of work is at risk of flooding from rivers or the sea by calling the Environment Agency's Floodline on 0845 988 1188 or by visiting the website.
If you are at risk, sign up to receive free flood warnings. You can receive these by phone call, text and e-mail and they will give you a heads up when flooding is expected.
The Environment Agency also encourage people to think about the following:
* Find out if your insurance covers flooding.
* Have a flood plan - this would include lists of important contact details as well as information about what you would need
* Do you know where you could move your car too and would you be able to pick your children up from school?
* Do you know where you can turn off your gas, electricity and water supplies?
* Do you have neighbours who might need help?
* Put together a flood kit - include a wind up or battery operated torch and radio (to listen out for more information), warm and waterproof clothing, water, food and medication. Don't forget toys and food for children and pets.