Towns Built on Land That's Slowly Sinking
Towns are built on the stability and solidarity of the people around them and the earth below. Unfortunately, that is not the reality for many town in America and across the world. Unfortunately, this is not the reality for many towns in the U.S. and around the world.
Parts of the town of Corcoran in California have sunk more than 11 feet since 2005. Wenden, Arizona, is sinking due to depletion of the underground water supply, damaging local infrastructure. This sinking process, called land subsidence, happens when the Earth's surface settles or collapses inward. Whether caused by pumping too much water out of underground aquifers, thawing permafrost, or constant drilling for oil, these seven towns continue to lose ground, literally.
Corcoran, California
In 2021, it was widely reported that Corcoran, a Kings County farm town about 50 miles south of Fresno in California's San Joaquin Valley, sank by as much as 11.5 feet over 14 years. It was estimated that while parts sank that far, every part of the town's 7.47 square miles was experiencing subsidence.
Some areas of the soil dipped by a few inches while others by nearly two feet. A local water management agency estimates the city will sink another six to 11 feet over the next two decades. The impact has already been felt, with water well casings crushed and flood zones shifted. Residents have already had to pay for a new town levee.
The main cause of subsidence is farming, including groundwater pumping for crop irrigation that has been done for many decades, worsening the problem. A plan has been put in place to set limits on allowable future subsidence to manage aquifers.
Mendota, California
Mendota, nearly 30 miles west of Fresno, also lies in the San Joaquin Valley, and groundwater pumping is to blame for the town and the surrounding stretch of Fresno County slowly sinking over time. The Delta-Mendota Canal is also affected by subsidence, resulting in the canal carrying less water.
A project is in the works to restore the canal, and the work has extended into Merced County, as well.
Mendota is often considered 'ground zero' for agricultural land subsidence because it lies over the Corcoran Clay aquitard. Well water pumping between 1925 and 1977 kickstarted the problem, with the land just southwest of Mendota sinking nearly 30 feet, a spot the U.S. Geological Survey used for one of the most famous photographs in the field.
Groundwater is still pumped today, causing more slow sinking. The surface water of the surrounding canals is helping to curb the rate of sinking, but cannot stop it completely.
Isle de Jean Charles, Louisiana
The permanent population on Isle de Jean Charles, in Terrebonne Parish, Louisiana, has all but vanished due to the threat of coastal erosion and rising sea levels and has already lost 98 percent of its land since 1955.
While there is a debate about whether the sea is encroaching on Louisiana or the state is falling into the sea, the island has only half a square mile left showing above the water. It was once a flourishing destination spanning 22,000 acres, but oil and gas drilling, canal dredging, and the loss of trees have caused massive problems.
Inhabitants were promised a move to New Isle which sits above the floodplain, but the Jean Charles Choctaw Nation were left out of the discussions. This has caused a split, with most tribe members settling on New Isle, but a handful refusing to leave Isle de Jean Charles.
Since there are no formal plans to protect the island with a levee system, it is safe to assume that what is left of it will eventually disappear completely.
Grand Isle, Louisiana
Grand Isle, Louisiana's last inhabited barrier island, is in the same boat as Isle de Jean Charles. The island is experiencing one of the fastest rates of relative sea-level rise on the planet, a combination of water rising and land sinking that adds up to nearly half an inch every year.
It also sits right in the Gulf of Mexico, and as sea levels continue to rise, it becomes exposed to higher hurricane storm surges.
Louisiana adopted a Climate Action Plan and then adopted the 2023 Coastal Master Plan. Both are intended to fight sea level rise and reduce emissions, which can help slow Grand Isle's sinking. These are urgent measures, since losing barrier islands means flooding in coastal towns and further damage along the coast, right into the cities.
Wenden, Arizona
About 100 miles west of Phoenix, the desert town of Wenden is also sinking due to too much groundwater being pumped beneath it. Estimates of how far vary with state monitoring recording roughly 3.5 feet of subsidence over 15 years, researchers put the wider McMullen Valley at more than five feet since 1991, and Arizona's attorney general has said the town has dropped four feet.
Either way, the ground is still falling 2 to 3 inches a year. The main culprits are large corporations taking advantage of Arizona's lack of limits on rural groundwater. Outside the state's designated management areas, these operations pump massive amounts of water from underground wells and do not have to report how much they take.
As the water levels drop, the soil beneath develops empty spaces. These spaces eventually collapse, causing the surface to sink.
It is becoming an increasing nightmare for the locals. Residents of the McMullen Valley, which spans parts of La Paz, Maricopa, and Yavapai counties and includes Wenden, Salome, and Aguila, have formed their own political action committee and are gathering signatures to force a special election in March 2027 on whether to designate the basin an Active Management Area, which would finally regulate pumping.
Without limits of some kind, Wenden faces severe structural damage, and the town could also be left without potable water.
Tangier Island, Virginia
Researchers predict that Tangier Island will lose most of its remaining land within a century, and a widely cited 2015 study in Scientific Reports concluded the town would likely have to be abandoned in roughly 50 years. A bleaker 2021 assessment warned that most of the remaining residents could be forced out within a decade.
Tangier has lost two-thirds of its landmass since 1850, largely due to sea level rise, erosion, and land that is still settling as the Earth's crust adjusts after the last ice age.
Today, the island rises only around three feet above sea level, while the water of the Chesapeake Bay surrounding it rises by a quarter of an inch every year. There is no real help other than a rock seawall the Army Corps of Engineers built along the western shore around 1990 and a jetty contracted in 2020.
While the U.S. Geological Survey monitors rising sea levels, estimates put the cost of fully protecting the island at $250 million to $350 million, against roughly $100 million to $200 million to move its remaining 400 or so residents to the mainland.
Shishmaref, Alaska
An Inupiat community of about 600 people on Sarichef Island in the Chukchi Sea, Shishmaref has occupied the same quarter-mile-wide barrier island for thousands of years. Melting permafrost and rising sea levels are now causing destructive land erosion, roughly three to five feet of shoreline a year, with far more in a single bad storm.
More than 30 feet disappeared in 1997, forcing 14 homes to be moved. The disappearing sea ice that once broke up autumn storms offshore means surges now reach the village directly.
Residents have voted to relocate three times, first in 1973, again in 2002, and most recently in August 2016, when the tally was 94 to 78 in favor of moving five miles to the Alaska mainland.
Unfortunately, the estimated $180 million it would take has never materialized, and some residents are not interested in moving. An Army Corps assessment in 2006 gave the current site 10 to 15 years, and Shishmaref is one of dozens of Alaska villages the Corps considers under imminent threat.
Living on Unstable Ground
Municipalities and communities are scrambling to find ways to slow the damage caused by erosion before it is truly too late.
Measures include importing surface water or setting limits on how much underground water can be pumped. Some are even trying to pump fresh water back into the soil to keep it from crumbling. Coastal towns have to consider raising levees and building stronger seawalls.
As beaches shrink, municipalities are dumping fresh sand, but these are temporary measures. When they stop working, or the money runs out, communities will face the reality of packing up and moving to more solid ground.
