{"id":30643,"date":"2026-07-31T17:17:00","date_gmt":"2026-07-31T21:17:00","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=30643"},"modified":"2026-07-31T17:17:00","modified_gmt":"2026-07-31T21:17:00","slug":"39-trillion-figure-attached-something-americans","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/39-trillion-figure-attached-something-americans\/30643\/","title":{"rendered":"A single acre of American wetlands can hold 1 million gallons of floodwater, and the country drained about a billion acres of them before anyone counted the cost"},"content":{"rendered":"

It looks like wasted land<\/strong>, a few acres of cattails and standing water, smelling faintly of mud and buzzing with insects in July heat.<\/p>\n

So Americans have spent a century filling places like this in, leveling them for subdivisions and farms and parking lots.<\/p>\n

Yet an acre of it can hold over a million gallons<\/strong> of floodwater before any of that water reaches a downstream house.<\/p>\n

And nobody put a price on that until researchers ran the numbers, which came back as one of the largest<\/strong> figures in modern environmental science.<\/p>\n

The summer that made everyone look down<\/h2>\n

July 2025 arrived with a ferocity that felt personal.<\/p>\n

It opened with flash floods in a stretch of Texas known as Flash Flood Alley, where the Guadalupe River in Kerr County rose 26 feet<\/strong> in under an hour.<\/p>\n

By the time the water dropped it had killed more than 130 people, among them 27 campers and counselors at Camp Mystic alone.<\/p>\n

Then barely two weeks later a stretch of brutal midsummer heat gripped the interior of the country from 21 to 25 July.<\/p>\n

In all, nearly 160 million people<\/strong> saw at least one day of extreme heat that climate change had made at least three times more likely.<\/p>\n

As Kristina Dahl of Climate Central put it, this was not your grandmother’s heat wave<\/strong>.<\/p>\n

That is two disasters and two kinds of water, with one overlooked ecosystem sitting at the center of both.<\/p>\n

The land nobody wanted<\/h2>\n

For generations the American instinct was to drain it.<\/p>\n

Because marshes, swamps, bogs, prairie potholes and river floodplains all stood between farmers and fields, between developers and buildable ground.<\/p>\n

So by the twentieth century, draining them counted as an act of progress<\/strong>.<\/p>\n

Worldwide since 1970 more than a billion acres<\/strong> of wetland have gone, roughly 22 percent of the total, at an average rate of 0.52 percent a year.<\/p>\n

And American wetlands led that decline, where the state by state numbers turn brutal.<\/p>\n

Iowa lost about 90 percent<\/strong> of its original wetlands and California more than 90 percent, while the lower Mississippi Valley gave up nearly all of it.<\/p>\n

Nobody counted the cost, because nobody believed there was one to count.<\/p>\n

What the marsh was actually doing<\/h2>\n

Here is what a wetland does before a flood arrives.<\/p>\n

It regulates water flow, which slows a surge on the way down and holds supply through a drought.<\/p>\n

That is where the million gallons an acre comes from, and it is free storage<\/strong> nobody has to build.<\/p>\n

Then in a heat wave, coastal marshes and river floodplains hold local temperatures down by releasing moisture into the air.<\/p>\n

Which amounts to living air conditioning<\/strong> that runs on rain and needs no grid connection at all.<\/p>\n

On top of that, wetlands host 40 percent<\/strong> of global biodiversity while disappearing faster than any other ecosystem on Earth.<\/p>\n

So the great blue heron standing still in the shallows is not just a nice sight, it is a sign the system still works.<\/p>\n

The 39 trillion dollar number<\/h2>\n

In July 2025 the Convention on Wetlands published its most comprehensive assessment of the world’s wetlands to date.<\/p>\n

The finding that stopped economists cold was that what remains delivers up to 39 trillion dollars<\/strong> in benefits every year, according to the convention<\/a>.<\/p>\n

Which is more than the entire annual economic output of the United States.<\/p>\n

The same report priced everything already drained over the past fifty years at another 5.1 trillion dollars on top of that<\/strong>.<\/p>\n

And without action, up to a fifth<\/strong> of what is left could vanish by 2050.<\/p>\n

Restoration is not free either, running from roughly 400 to 28,000 dollars an acre a year depending on the site.<\/p>\n

But for the towns that lost homes on the Guadalupe last July the arithmetic is not abstract, because the small rivers<\/a> running through American towns were once buffered by marshes that took the surge before it reached a front door.<\/p>\n

And cities that lost their wetland cover also lost the cooling layer that summer nights<\/a> expose most brutally.<\/p>\n

The thing that can still come back<\/h2>\n

Even so, the report is not a eulogy, because it also collects cases where the trend reversed.<\/p>\n

In the Kafue Flats of Zambia a 300,000 dollar restoration effort pulled in wider investment in biodiversity, water systems and livelihoods, supporting some 1.3 million people in the process<\/strong>, as the UN<\/a> documented.<\/p>\n

Closer to home, restoration along the Gulf Coast and the Mississippi corridor is already slowing runoff and cooling the air in nearby neighborhoods.<\/p>\n

Because wetlands, unlike almost anything else in the climate toolkit, can grow back<\/strong>.<\/p>\n

Give a marsh its water and within a few years the cattails return, the herons return, and so does the flood barrier no engineer had to pour.<\/p>\n

So what looks like a pile of mud and standing water turns out to be worth more per acre<\/strong> than almost any building ever put in its place.<\/p>\n","protected":false},"excerpt":{"rendered":"

It looks like wasted land, a few acres of cattails and standing water, smelling faintly of mud and buzzing with insects in July heat. So Americans have spent a century filling places like this in, leveling them for subdivisions and farms and parking lots. Yet an acre of it can hold over a million gallons of floodwater before … Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":30866,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"39 trillion figure","rank_math_title":"A single acre of American wetlands can hold 1 million gallons of floodwater, and the country drained about a billion acres of them before anyone counted the cost","rank_math_description":"A landmark 2025 report put a $39 trillion price tag on the world's wetlands \u2014 and what they do for US floods and heat is something most Americans never pi","footnotes":""},"categories":[24],"tags":[],"class_list":["post-30643","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-climate"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/30643","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=30643"}],"version-history":[{"count":0,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/30643\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/30866"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=30643"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=30643"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=30643"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}