Tuesday, May 28, 2024

Opinion | When to act on climate change? Before your drinking water turns salty.

Opinion | When to act on climate change? Before your drinking water turns salty.


Olivia Henry, 6, uses bottled water to refill their cat’s water machine at their home in Buras, La., on Oct. 4. (Kathleen Flynn for The Washington Post)

Joseph Kanter, Louisiana’s top medical official, had some cold comfort for New Orleans residents worried about saltwater snaking up the Mississippi River that threatens the city’s drinking water.

“For the vast majority of people,” he said last month, “you will stop drinking the water because it doesn’t taste well well before it becomes a danger to your health.”

Folks hearing such statements could hardly be blamed for panic-buying bottled water, despite pleas to stay calm. For frustrated local officials, here’s a radical idea: Stop waiting for climate disasters to strike before acting. Instead, assess potential threats and adapt now.

New Orleans has been counting down the days to when its freshwater might become undrinkable. Officials project that, unless rainfall recharges the Mississippi, corrosive seawater could reach the city’s treatment plants by late November. That could disrupt residents’ access to water and wreak havoc on infrastructure in the area.


Forecast of saltwater moving up

the Mississippi River

When the river doesn’t have enough water flowing, saltwater begins to move upriver from the gulf. The latest forecasts show that saltwater is likely to stop advancing near West Jefferson.

The surface water here started to contain salt.

Pointe à la Hache

(inundated)

Source: Army Corps of Engineers, data as of Oct. 4.

YAN WU/THE WASHINGTON POST

Forecast of saltwater moving up

the Mississippi River

When the river doesn’t have enough water flowing, saltwater begins to move upriver from the gulf. The latest forecasts show that saltwater is likely to stop advancing near West Jefferson.

The surface water here started to contain salat.

Pointe à la Hache

(inundated)

Boothville

(inundated

by saltwater)

Source: Army Corps of Engineers, data as of Oct. 4.

YAN WU/THE WASHINGTON POST

Forecast of saltwater moving up the Mississippi River

The latest forecasts show that saltwater is likely to stop advancing near here.

The surface water here started to contain salt.

Boothville

(inundated by saltwater)

When the river doesn’t have enough water flowing, saltwater begins to move upriver from the gulf.

Source: Army Corps of Engineers, data as of Oct. 4.

YAN WU/THE WASHINGTON POST

Forecast of saltwater moving up the Mississippi River

The latest forecasts show that saltwater is likely to stop advancing near here.

The surface water here started to contain salt.

Boothville

(inundated by saltwater)

When the river doesn’t have enough water flowing, saltwater begins to move upriver from the gulf.

Source: Army Corps of Engineers, data as of Oct. 4.

YAN WU/THE WASHINGTON POST

The briny predicament is the result of drought in the regions that feed the Mississippi River. The lack of rain has sapped the Mississippi’s strength to such an extent that it is losing its perpetual wrestling match with the ocean. Usually, the river’s flow is strong enough to keep the saltwater in the Gulf of Mexico — where it belongs. Now, the Mississippi is so diminished that the sea is pushing north.

State and local officials have scrambled to prevent the worst-case scenario. The U.S. Army Corps of Engineers built up a sill of sediment on the bottom of the river to hinder the gulf’s advance. Because saltwater is heavier than freshwater, it flows beneath the river and must overcome obstacles on its floor to move forward. But this can only slow down the so-called saltwater “wedge.”

Saltwater can be made drinkable by reverse-osmosis filtration systems, but such technology could not meet the demands of a metropolitan area as large as New Orleans, which is home to more than 1 million people. Nor it is likely that officials can barge in enough water from elsewhere.

Instead, the plan is to construct a temporary 15-mile pipeline that will pump water from upstream to dilute the salt contamination. The project will cost as much as $250 million, covered mostly by federal emergency funds. Officials are confident the pipeline will be ready before the wedge reaches the city.

In the end, the problem might solve itself. The wedge has slowed, and rain might strengthen the river and turn it back. But even if that happens, the episode illustrates just how unprepared cities are to deal with the changing climate. Many smaller communities downstream from New Orleans have been inundated with saltwater for weeks.

It would be unfair to criticize local officials too harshly for not anticipating this disaster. Though there have been plenty of years of low flow, the region last saw such a dire threat of saltwater intrusion in 1988.

Still, it’s clear that what used to be “extreme” weather events are no longer all that rare. The last time the Mississippi faced dangerously low flow was, well, last year. In fact, this is the first time the river has seen such low flow in two back-to-back years. In 2022, thousands of barges were stranded on sandbars, upending supply chains across the nation. A saltwater wedge did spill over an engineered sill, but the river turned it back before it could do any damage.

Communities along the river must do a better job preparing. This could mean building more sills, osmosis units and permanent pipelines, or investing in desalination plants. Many of these solutions are expensive, but they beat asking residents not to panic whenever it stops raining.

This lesson applies across the country. With what used to be once-in-a-century storms coming every decade, regions prone to flooding must prepare now: hardening their infrastructure, protecting wetlands and prohibiting development in areas that make no sense. And as wildfires become more common and more intense, states must update building codes and revamp their risk maps, as Oregon is doing.

Adapting to our changing climate doesn’t mean giving up on slowing that change. In fact, transitioning away from fossil fuels is essential to America’s adaptation mission. It’s highly unlikely the world will keep the average rise in global temperature to under 1.5 degrees Celsius (2.7 degrees Fahrenheit) — a shameful failure on the part of governments. But leaders can and must stop warming from getting even worse by limiting the amount of carbon emitted.

The Mississippi, Mark Twain once wrote, “will always have its own way; no engineering skill can persuade it to do otherwise.” With respect to the great American writer, this is wrong. New Orleans — and the rest of the country — deserves a government with greater ambition.



Source link