Flood Season

The rainwater flowed into my central New Jersey home on Monday night, carving rivulets across my floor that grew into streams and then ponds. My sump pump was quickly overmatched; so was my wet vac. A second pump, which I hoped would drain pooling water through a window, shot a geyser of brown basement liquid into my face.

My battle against the elements left me with a sore back and a cellar full of sopping mementos, musical instruments and holiday decorations. But I got off easy. The flash floods did far more damage just a few towns over. There, roads became rivers. Two people died when fast-rising waters carried their car into a stream. “Water has killed more people in my time as governor than any other sort of weather event,” Gov. Phil Murphy, a Democrat, lamented yesterday. He blamed climate change.

Many factors influence the weather, and scientists don’t like to say that climate change caused this specific storm or that one. But researchers know that climate change is causing heavier rainfall in many storms — the warmer the atmosphere gets, the more moisture it can hold and release. Extreme rainstorms have become more common around the world.

The last month has brought a rush of the resulting floods. Over a single week, the water surged in New Mexico, Illinois, North Carolina and Texas, where the deluge killed more than 130 people.

Are you safe?

Flash floods are the hardest disasters to prevent. What should you know about your neighborhood’s flood risk? Claire Brown, who covers the climate, talked to experts about why you may be at more risk than you think, what you can do about it and how local governments are adapting.

FEMA’s flood maps. The agency publishes maps that inform zoning regulations and building standards. They also affect which homeowners have to buy flood insurance. (Search for your address here.) But experts worry that these maps underestimate the risk of sudden and intense storms that lead to the rapid rise of rivers — such as the one that inundated Camp Mystic in Texas this month. By one estimate, more than twice as many properties are prone to once-in-a-century floods as FEMA maps suggest. As many as 440,000 homes across the country may be underinsured for flood risk.