President Trump’s border wall scarred the environment, but so did President Biden’s decision to halt all work, according to a new report Thursday which said the new administration ended up stopping all the remediation work that had been planned to repair the lands.

Now, erosion has gotten so bad that it “is now undermining the integrity of the panels that contractors installed,” according to Congress’s Government Accountability Office.

The problem was the breadth of Mr. Biden’s 2021 order stopping all wall activities. It meant the contractors put down tools and walked away, leaving miles of unfinished wall, which Mr. Biden intended. But it also meant they stopped working on all the remediation already planned, such as installing drainage culverts and repairing floodplains to control erosion.

“In multiple locations in Arizona, we observed erosion occurring adjacent to the border barrier along patrol roads where contractors did not complete installing culverts and other erosion control measures when projects were paused and contracts were ultimately canceled, threatening the integrity of the barrier system,” GAO said.

Investigators said they found the same problem at sites in California, where erosion is “undermining” the wall.

GAO was asked by House Democrats to look at the overall environmental impact of the wall, and investigators found plenty of issues of concern.

They dinged the previous administration for running roughshod over environmental laws, skimping on collaboration with state, local and tribal governments and wreaking havoc on the land by carving habitat for wolves and ocelots, draining scarce water sources, disturbing birds’ migratory routes and destroying sites that were culturally important to Native Americans living along the border.

But Mr. Biden’s construction halt made some of the problems worse.

In one troubling example, GAO investigators said contractors building sections of the wall in Arizona had to move a bunch of saguaros — the iconic cactus with arms pointed to the sky that only grows in the Sonoran desert — out of the way.

They transplanted the saguaro nearby and were nurturing them, but when Mr. Biden took office and ordered a halt to wall activities that meant no more watering or tending the trees, either, according to an official from the Tohono O’odham Nation, which has occupied border lands for centuries.

“As a result, the official estimated that as many as half of the transplanted cacti did not survive in some locations,” GAO investigators said.

At a location in Texas, meanwhile, GAO investigators found that contractors had cleared a space to stage equipment and were supposed to reseed the land when they left. But Mr. Biden’s construction halt blocked the repairs, and now invasive species have taken over the site.

In New Mexico, a contractor built a road up against the wall but eight feet above the floodplain. Now water pools up against the base of the wall, rather than flowing into Mexico.

Under Mr. Trump, the feds erected 458 miles of new barriers. Of that, 87 miles were built where no previous barrier had existed, 176 miles were built where a previous outdated version of fence existed, and 195 miles were built where there had been a vehicle barrier but no actual fencing.

A lot of the construction took place on federal lands, including in some of the country’s most pristine desert wilderness.

The Tohono O’odham Nation said the feds used explosives to clear the way for constructing a road next to the wall. Roads are a critical part of the wall system.

However, the explosives damaged part of Monument Hill, a burial site and religiously significant location for local tribes.

In Texas, building the wall has fractured the habitat of the ocelot, severing migration corridors and elevating the risk of the ocelot’s extinction in the U.S., GAO said.

In Arizona, the demand for water at one site was so heavy that contractors drained groundwater stocks, which dried up ponds on the San Bernardino National Wildlife Refuge. Those ponds are home to some endangered and threatened species, GAO said.

The Biden administration is making plans for restoration work, but Mr. Biden’s actions are hindering that, too.

In addition to halting wall work in 2021, he also canceled the national emergency Mr. Trump had declared and used to tap Defense Department funds. Without a national emergency, the government can’t waive certain laws. That means the administration must now go through an environmental impact assessment before it can begin repairs.

“In the meantime, CBP officials said that conditions at some of these project sites continue to diminish. For example, they noted that erosion at one site in California — made significantly worse due to high amounts of rainfall — is now undermining the integrity of the panels that contractors installed,” GAO said.

CBP has set aside $50 million for environmental repairs, but GAO said that’s not going to be enough to cover all the work that will be needed.

Mark Morgan, who oversaw wall construction as head of CBP in the Trump administration, defended their decision-making, saying they made the right choices.

“We applied a common sense balanced approach in an effort to address environmental concerns while prioritizing our main goal of securing our nation’s border to reduce a vast set of complex threats from entering the U.S.,” he said. “Speaking personally, if we disrupt a butterfly habitat or a few cacti die in exchange for disrupting the cartel’s operational capacity to threaten our nation’s safety and national security, I’m okay with that trade-off.”

GAO, in its report, urged CBP and the Interior Department to come up with a better strategy for caring for cultural and natural resources endangered by wall construction and to study lessons to be learned from the last round of wall-building.

The departments agreed with all of the recommendations.

“DHS remains committed to coordinating with stakeholders regularly to ensure environmental planning for projects is inclusive and comprehensive,” Jim H. Crumpacker, Homeland Security’s liaison to GAO, said in the department’s official response.

The White House did not respond to an inquiry for this story.

GAO said in its report that there were some positive impacts to the environment from the wall. For one thing, it has cut down on the amount of trash migrants dump on the lands as they traipse through. There are also fewer footpaths being cut across wilderness deserts, land managers said.

• Stephen Dinan can be reached at sdinan@washingtontimes.com.