The federal government is spending hundreds of billions of dollars on a generation of new roads, bridges and sewers \u2014 which could be overwhelmed by floodwaters the moment they are installed.<\/p>\n\n\n\n
That\u2019s because federal estimates about flood risk haven\u2019t kept up with climate change, according to a study published on Monday in the Journal of Hydrology.
First Street Foundation was auditing the gold standard of government rainfall calculations: the National Oceanographic and Atmospheric Administration\u2019s (NOAA) Atlas 14 model.<\/p>\n\n\n\n
These projections of future risks of catastrophic downpours are a current key determining factor in the engineering standards by which $1.3 trillion in new infrastructure \u2014 paid for by a bipartisan 2021 legislative package \u2014 will be built.<\/p>\n\n\n\n
But according to First Street\u2019s report on Monday, even the best government estimates are \u201cfundamentally flawed.\u201d<\/p>\n\n\n\n
That means the very infrastructure intended to bolster American cities against a changing climate may continue to put those cities at risk, said Matthew Eby, executive director of First Street Foundation, in a statement.<\/p>\n\n\n\n
Many of these projects, Eby said, \u201cwill be out of date on the day they are opened to the public.\u201d<\/p>\n\n\n\n
As an example, Eby described to The Hill a project he had observed in New Jersey, where \u201cthey are spending 86 million over 4 years to fix a stretch of road that continuously floods.\u201d
But, Eby said, \u201cI was watching them build it to the wrong standard. When the project is complete, our data shows it will still flood every other year.\u201d<\/p>\n\n\n\n
Such misaligned fixes, Eby said, \u201care all over the country.\u201d<\/p>\n\n\n\n
First Street\u2019s findings were stark: that government had been substantially undercounting the risk of heavy rains that more than 100 million Americans lived under.
The nonprofit found that 51 percent of Americans live in areas where their risks of going through a \u201c1-in-100 year\u201d flood are twice the official estimate, while 21 percent can expect to see such a severe storm every 25 years. (To see the climate risk to 2050 for any freestanding home, click here.)<\/p>\n\n\n\n
And for many heavily populated cities, the odds are worse than that. New York, N.Y. can now expect a hundred year flood every 23 years; while Washington, D.C. and Dallas, Texas can expect one every 21 years, and Baltimore, Md. will face one every 14 years.<\/p>\n\n\n\n
Because the hundred year flood represents the benchmark to which urban stormwater systems are typically calibrated, that means more than 100 million Americans \u201creside in a county where stormwater system failure is likely to occur today,\u201d First Street authors wrote.
For some cities, the uptick in risk is particularly steep. Houston, Texas currently faces a more than fourfold increase in what used to be 100-year floods \u2014 the same odds as New York City.<\/p>\n\n\n\n
But by 2053, Houston will have pulled ahead in their grim race \u2014 with that erstwhile 100-year flood now happening every 11 years.<\/p>\n\n\n\n
The reason for the discrepancy is as simple to state as it is hard to fix: the federal government still doesn\u2019t factor climate change into its long-term weather estimates.
Instead, NOAA built Atlas 14 on the core assumption that the underlying risks of devastating rains \u2014 however severe they might be \u2014 \u201cdo not change significantly over time,\u201d as a 2022 federal audit found.<\/p>\n\n\n\n
Under this system, weather behavior was presumed to be circular, such that \u201cfuture climate conditions can be represented by the past observed precipitation,\u201d the auditors found.<\/p>\n\n\n\n
With such an expectation of stable long-term conditions \u2014 or what prediction scientists call \u201ctemporal stationarity\u201d \u2014 a historic hundred year flood, for example, should continue to happen on average about every hundred years, and to do so with relatively consistent intensity.
That was a fairly safe bet for most of the climatologically stable 20th Century \u2014 and one which was already failing by century\u2019s end.<\/p>\n\n\n\n
Since every additional degree Fahrenheit of air temperature leads to just under 4 percent more water in the air, the dramatic rise in temperatures has come alongside a much higher instance of powerful, flood-causing rains.<\/p>\n\n\n\n
A 2018 study that compared federal and state projections between 1961 and 2000 with the actual recorded rainfall totals found a persistent mismatch for 90 percent of areas studied.
Those findings raised the risk that stormwater infrastructure could be strictly built to code \u2014 and still \u201cbe under-designed for present and future climate conditions,\u201d the scientists wrote in Environmental Research Letters.<\/p>\n\n\n\n
That prediction seems to be coming true. Over the past 20 years, NOAA\u2019s network of rain gauges have tracked 30 places which experienced multiple instances of what should have been \u201c1-in-100 year events\u201d as classified by Atlas 14, according to First Street.<\/p>\n\n\n\n
And last summer, the U.S. saw five of what were predicted to be 1-in-1000, as deluges flooded St. Louis, Mo. and Dallas, Texas while stranding hikers in Death Valley, Calif.<\/p>\n\n\n\n
To make prediction even harder, as a previous First Street study found, the master flood risk maps prepared by the Federal Emergency Management Agency don\u2019t include precipitation at all.<\/p>\n\n\n\n
Government data \u2014 which typically tracks the amount of rain that fell in a 24-hour period \u2014 also often obscured the new intensity in modern storms.<\/p>\n\n\n\n
While it is true to say that Fort Lauderdale, Fla. experienced more than two feet of rain in one day in mid-April, the First Street team noted, \u201cit fails to acknowledge that \u2026 26 inches of rain fell in just 6 hours.\u201d<\/p>\n\n\n\n
That new intensity means that even systems that could handle the new daily volume \u2014 if, say, the 26 inches had been evenly spread over 24 hours instead of compressed into six \u2014 risk being overwhelmed.<\/p>\n\n\n\n
These are problems that NOAA itself is well aware of. The 2022 audit cited above came about as an early step in the ambitious and unprecedented process \u2014 also funded by the 2021 infrastructure package \u2014 of turning federal climate predictions from backward looking to forward looking.<\/p>\n\n\n\n
The agency is currently working on proposed updates to Atlas 14 (called Atlas 15) to account for climate change \u2014 and to \u201cdevelop precipitation frequency estimates for the entire U.S.\u201d<\/p>\n\n\n\n
But the agency doesn\u2019t plan to have those results ready until 2027 \u2014 and design and construction for new infrastructure is already underway using the old numbers.<\/p>\n\n\n\n
For First Street Foundation, that lack of data constitutes a considerable near-term market opportunity.
As The Hill has reported, the nonprofit has in the past decade carved out a unique business in predicting the likelihood that a given property will be impacted by extreme weather \u2014 like floods, fires, extreme heat, wind and now rain.<\/p>\n\n\n\n
That has made them a crucial resource for banks, realty companies \u2014 and government agencies, many of which contract to use First Street\u2019s peer-reviewed data in their own planning.<\/p>\n\n\n\n
First Street\u2019s new model \u201cimmediately allows for insights and informed actions today that otherwise would have to wait until NOAA\u2019s completion of Atlas 15,\u201d the company wrote in a press release.<\/p>\n\n\n\n