El Nino is expected to drench California in the coming weeks, and FEMA is urging people to take action now to prevent serious damage later.
The agency said it's time for those living in flood-prone areas to buy flood insurance now because it takes 30 days for flood insurance to go into effect and prepare their homes for an emergency.
Insurance is one of many things people should do to prepare for heavy rain. Typically, when fall rolls around, the roofing business gets busy.
"They all decide at the same time it's time to take care of the roof!" said Fred Gregory, owner of River City Roofing Company.
This year Gregory is swamped.
"Probably the busiest I've ever seen it in well over 30 years," he said.
It's partially because during severe drought roofs tend to get neglected.
"There just hasn't been enough rain to cause them any grief," Gregory said.
But this year, many homeowners are scrambling.
Forecasters are predicting this year's El Nino will be one of the strongest on record.
FEMA is urging people to prepare immediately by getting flood insurance before the rain hits like it did New Year's Day 2006. Regular homeowner's insurance will not cover flooding.
Even those who don't live in "high risk" areas are urged to get coverage. According to FEMA, just a couple of inches of water can do thousands of dollars in damage to a home.
Last year, the average premium for a flood insurance policy cost $700 spread out over the year -- that's a little more than $58 a month.
Whether or not the predictions hold true, residents seem to be responding and it's keeping the roofing industry busy.
Replacing a roof can cost about $6,000 to $8,000, but it could prevent more costly damage from heavy downpours.
FEMA said last week that more than half the people who should have flood insurance do not.
For more information and to see how flood prone your area is, check out floodsmart.gov.