If flooding in your area is from sewer backup or basement, your own water alarm can give you precious lead time before your belongings are damaged by floodwaters. Develop a flood response plan based on the flood protection level, local warning procedures, and the time you will have to respond. In flash flood areas, you may only have enough time to evacuate. But if you live in areas in the path of a hurricane or on large rivers, you may have 12-24 hours of warning time. If you live in a mountainous area, or if your flooding comes from a small stream or ditch, your home may be subject to flash flooding.
Flash floods can occur before the local emergency managers have time to issue a warning.
In these cases, the National Weather Service may issue a flash flood watch advising people that conditions are favorable for a flash flood. You may not be notified of a flash flood warning before flooding actually begins. If you hear a flash flood watch for your area, it's a good idea to stay on high ground. If you hear a flash flood warning , climb to higher ground immediately. Leave your car, camping gear, or other belongings where they are.