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Infrastructure funds will help prepare cities for rain. But how much rain is coming?


The U.S. will soon make the largest investment in its water infrastructure in the country's history. The federal infrastructure bill will send billions to states and cities to prepare for climate change. Cities know their water systems need to handle more intense rainfall, but the problem is they have little information about how much rain is coming. NPR's Lauren Sommer has the story.

LAUREN SOMMER, BYLINE: It was just starting to rain in San Francisco back in December. And as it does in every city, the water hits the pavement and flows into the least glamorous and least appreciated piece of infrastructure around.

MIRA CHOKSHI: You can call it a storm drain, a catch basin, a gutter.

SOMMER: Mira Chokshi is an engineer with the San Francisco Public Utilities Commission. She says those lowly storm drains are what stop cities from flooding. With so much pavement around, the water can't sink into the ground, so it flows into a huge network of pipes under our feet. But in a big storm with lots of rain, there's just too much water.

CHOKSHI: Stormwater runoff that's on the street cannot go through the storm drain and enter the pipe, and that water ponds.

SOMMER: That's when intersections get flooded, stopping traffic. Water flows into people's basements and houses. This happens in most cities because stormwater systems get overwhelmed. They were designed without climate change in mind because they're tailored to the rainstorms of the past. But in a hotter climate, storms release even more rain, says San Francisco Public Utilities project manager Anna Roche.

ANNA ROCHE: We expect a storm to drop more water in a shorter duration of time. And so there's - you know, there's a lot of water coming, and what are we going to do with it?

SOMMER: But how much more water? That's where cities are running into trouble. There are nationwide studies on extreme rain, but cities don't have something localized to their area.

ROCHE: There's no book. There hasn't been, you know, plans that have been developed for any of this stuff. So every city in the United States is grappling with this.

SOMMER: And for many cities, even the rainfall data they do have is dangerously outdated.


GREG ABBOTT: Our top priority is to protect human life.

SOMMER: In 2017, Hurricane Harvey stalled right over Houston. Governor Greg Abbott warned that the danger wasn't just from the wind.


ABBOTT: There will be a tremendous amount of rain dropped on miles upon miles of Texas.

SOMMER: As much as 60 inches of rain fell, causing $125 billion in damage. Even before Harvey, flood planners there knew that weaker storms could still be a problem. Their infrastructure, even stuff built recently, was designed for what storms looked like decades ago. Craig Maske, chief planning officer at the Harris County Flood Control District, says they knew they needed to update their rainfall records.

CRAIG MASKE: A lot of entities that were essentially using rainfall data on the order of 50 to 60 years old - and so there'd been a push for a while.

SOMMER: That meant the city wasn't building its infrastructure for the storms of today, where climate change has already made rainfall more intense. The old rainfall records Texas had were put out by the National Oceanic and Atmospheric Administration. The agency only puts out those reports when states request and pay for it themselves, which is why the records were so old. Texas agencies raised $1.75 million for NOAA to do new reports in 2016.

MASKE: May have been a case of be careful what you wish for.

SOMMER: The NOAA report found extreme storms have already gotten a lot worse in Texas. One kind of storm, known as the 1-in-100-year storm, used to drop 13 inches of rain. Now it drops 17 inches. That meant infrastructure projects needed to be built to handle more water. The costs for major road and highway projects in the Houston area went up by $150 million.

CHAD BERGINNIS: When you put a bridge in today, that bridge is going to be designed to last maybe 25, 50, 75 years.

SOMMER: Chad Berginnis is executive director of the Association of State Floodplain Managers.

BERGINNIS: So we really need to know and get an estimate of what that future condition is if we're going to design it properly.

SOMMER: Berginnis says states are poised to spend billions on their water systems with the federal infrastructure bill funding. Without updated rainfall or climate change data, there's a chance that infrastructure won't hold up in the future. And he says updating the rainfall records isn't expensive for the federal government in comparison.

BERGINNIS: The cost to do this is almost decimal dust when it comes to the overall federal budget. We're only talking probably about 3- to $5 million a year to produce these data.

SOMMER: NOAA's Mark Glaudemans, who oversees the agency's rainfall records, says the way they're doing it now, state by state, is not ideal.

MARK GLAUDEMANS: It would be much more efficient to do the whole country all at once. So by doing it in the piecemeal fashion that we have now, it does make it more expensive.

SOMMER: NOAA could get funding to do that from the federal infrastructure bill. The agency says it can't comment on whether it will provide new extreme rainfall data or climate change forecasts until it releases its spending plan later this spring. Lauren Sommer, NPR News.


Lauren Sommer covers climate change for NPR's Science Desk, from the scientists on the front lines of documenting the warming climate to the way those changes are reshaping communities and ecosystems around the world.