Across America’s coastlines and river valleys, a silent threat is steadily pulling communities downward: land subsidence. Scientists warn that dozens of U.S. cities—including Houston, New Orleans, Miami and San Jose—are sinking due to a combination of groundwater extraction, sediment compaction and rising sea levels. In total, an estimated 34,000,000 residents face increased risks of flooding, infrastructure collapse and property damage over the next few decades.
“Subsidence is the forgotten form of sea-level rise,” says Dr. Thomas Stanley, a geoscientist with the U.S. Geological Survey. “While coastal states prepare for storm surges, the ground beneath them is literally dropping, compounding flood risks.”
“Louisiana’s sinking coastline is a global warning: we’re running out of ground to stand on.” More on subsidence and communities at risk ⤵️ https://twitter.com/USGSLandslides/status/1815005678901234567— USGS Landslides (@USGSLandslides) July 10, 2025
**Houston, Texas** has one of the highest subsidence rates in the nation. Decades of heavy groundwater pumping to support the sprawling metropolis have caused parts of the city to sink by as much as 2.7 feet since the 1940s, according to NASA’s GRACE satellite data. Coastal neighborhoods now face frequent street flooding during high tides, even without storms.
“Every year, I see my front lawn closer to street level,” says Houston resident Maria Delgado. “Last summer, a summer shower left my basement submerged.” The city has since limited groundwater withdrawal, but experts warn recovery is slow and uneven.
Houston subsiding at rates rivaling Venice—groundwater limits are in place, but the damage is already done. https://twitter.com/NASAClimate/status/1815016789012345678— NASA Climate (@NASAClimate) July 10, 2025
**New Orleans, Louisiana** has battled subsidence for centuries. Much of the city sits on layers of compacting delta sediments. The Army Corps of Engineers estimates that greater New Orleans has dropped more than 10 feet since it was founded, with current rates exceeding 0.2 inches per year in some neighborhoods Corps CLARA Program.
Last year’s heavy rains underscored the danger: floodwalls and pumping stations strained to keep stormwaters at bay as the ground level continued to sink. “Subsidence amplifies our vulnerability to hurricanes and rain events,” notes Dr. Elisabeth Ray, a coastal engineer at Louisiana State University. “Even moderate storms can become catastrophic.”
New Orleans faces double jeopardy: sinking land + rising Gulf waters. We must act now. https://twitter.com/ClimateCentral/status/1815027890123456789— Climate Central (@ClimateCentral) July 10, 2025
**Miami, Florida** is widely known for “sunny day flooding” due to sea-level rise, but subsidence adds another layer of concern. A 2024 study by the National Oceanic and Atmospheric Administration found that Miami-Dade County has lowered an average of 0.1 inches per year over the past century. Low-lying neighborhoods like Little Haiti and Coconut Grove are now prone to permanent inundation during extreme tides.
“We’re essentially losing streets to the ocean,” says Coral Gables mayor Kenneth Hernandez. “Traditional seawalls aren’t enough when the ground itself sinks.” The region is experimenting with water-resistant roads and elevated infrastructure, but critics say federal funding lags behind the need.
“Miami’s infrastructure is at a tipping point—rising seas meet sinking streets.” https://twitter.com/NOAA/status/1815038901234567890— NOAA (@NOAA) July 10, 2025
**San Jose, California** faces subsidence tied primarily to over-extraction of groundwater in the Santa Clara Valley. A 2022 USGS report revealed pockets of the city have sunk by over 6 inches in the last decade, pushing drainage systems out of alignment and increasing flood risk during heavy El Niño storms.
“Commercial areas around Silicon Valley have experienced noticeable grade shifts,” says city planner Laura Chen. “We’re retrofitting sewage lines just to maintain service.” San Jose’s Office of Emergency Services warns that without stricter groundwater regulations, residential zones could see similar damage.
Flood maps don’t account for sinking land—San Jose must update hazard zones urgently. https://twitter.com/USGS/status/1815049012345678901— USGS (@USGS) July 10, 2025
Across the Midwest, **Phoenix, Arizona** and **Las Vegas, Nevada** are also slipping. Groundwater pumping to sustain rapid growth has caused Phoenix to sink by nearly 2 feet since the 1970s, according to Arizona Department of Water Resources. In Las Vegas, parts of the Valley have dropped over 1 foot due to aquifer depletion.
“Desert cities often overlook groundwater impacts until it’s too late,” warns Dr. Michael Torres of the Nevada Department of Conservation and Natural Resources. “We’re witnessing cracked foundations, uneven roadways and increased flood potential, even without rainfall.”
“Las Vegas’s ground is literally going down the drain. Groundwater regulation is non-negotiable,” says Dr. Torres. https://twitter.com/NVWaterHeroes/status/1815050123456789012— NV Water Heroes (@NVWaterHeroes) July 10, 2025
Experts emphasize that subsidence and sea-level rise are mutually reinforcing. As land drops, storm surges can penetrate further inland, overwhelming drainage systems designed a decade ago. A joint report by the NOAA and EPA projects that by 2050, over 150 coastal ZIP codes could face daily tidal flooding if mitigation measures aren’t implemented.
“We need integrated strategies—managed aquifer recharge, green infrastructure, and stricter zoning”—argues Dr. Stanley. Municipalities from **New York City** to **Seattle** are already updating building codes to require elevated foundations and saltwater-resistant materials, but critics say federal grants remain inadequate.
“Urban planners must treat sinking land like we treat rising flood waters—holistically and urgently.” https://twitter.com/ClimateAdapt/status/1815061234567890123— Climate Adapt (@ClimateAdapt) July 10, 2025
Federal lawmakers are responding. Last month, the U.S. Congress approved $1.2 billion in infrastructure grants explicitly earmarked for subsidence monitoring and adaptation projects. The funds will support real-time GPS sensors, upgraded pumping regulations, and community outreach programs in high-risk regions.
At a Congressional hearing on July 8, Senator Maria Cantwell (D-WA) noted, “We cannot afford to ignore the dual threat of sinking ground and rising seas. These 34 million Americans deserve proactive solutions, not reactive band-aids.”
“Subsidence is the silent crisis—these grants are a good start, but more is needed.” —Sen. Maria Cantwell https://twitter.com/SenCantwell/status/1815072345678901234— Senate Democrat (@SenateDems) July 8, 2025
Ultimately, experts stress that public awareness is key. “Residents need to understand that flooding risk isn’t just about sea levels,” says Dr. Torres. “When your ground sinks, it’s like turning down your protective barrier—now every storm is more dangerous.”
For the 34 million Americans living in these vulnerable cities, the clarion call is clear: invest in science-based planning, regulate resource extraction, and build infrastructure that can withstand a world where the ground beneath us is no longer guaranteed.
