The Biden administration on Thursday approved the completion of the Trump-funded US-Mexico border wall in an open area of southern Arizona near Yuma, where four large gaps make it among the busiest corridors for illegal crossings. The Department of Homeland Security said in a statement that work to complete the project near Morelos Dam will better protect migrants who could be injured if they slip down a slope or drown while wading through a low section of the Colorado River. The area is the third busiest crossing point for migrants who can easily cross the river to surrender to border officials. Completing the wall has been at the top of former US President Donald Trump’s agenda, and border security remains a strong issue for candidates of both parties heading into this year’s primaries. President Joe Biden halted construction of new walls after taking office, but has since made closing gaps south of Yuma a priority. Democratic U.S. Sen. Mark Kelly of Arizona, who is seeking his party’s nomination next week to defend the seat in November, pressed the Biden administration to close the loopholes, calling them a challenge for officials trying to secure the border . But Arizona environmentalist Miles Trafagen, who has been mapping the ecological damage caused by former President Donald Trump’s border wall construction, said closing the loopholes won’t be much of a deterrent. Traphagen said the Yuma area “has become the new Ellis Island for Arizona, with people arriving from countries as diverse as Ethiopia, Cuba, Russia, Ukraine, India, Colombia and Nicaragua. “People have traveled halfway around the world by plane, train and car,” he said, “so to expect that closing four small gaps will make them turn back and book a return flight on Air Ethiopia is a complete fallacy.” The statement announcing that Homeland Security Alejandro N. Mayorkas had approved the work to be done by Customs and Border Protection highlighted the “risks to the safety and lives of the region for immigrants attempting to cross into the United States ». A 5-year-old migrant girl crossing the water in a group drowned near the dam on June 6 when she was separated from her mother. The child’s body was later found in the river. US officials have not released the girl’s identity or nationality. But Jamaican newspapers reported that he was believed to be from that country. It was unclear when construction would begin. The statement said officials will move “as expeditiously as possible while maintaining environmental stewardship” in consultation with affected parties. The gaps are within an area for a barrier project that was previously funded by the Department of Defense and will be paid for by Homeland Security appropriations for fiscal year 2021. Environmentalists like Traphagen, meanwhile, have called for the removal of other parts of the dam that they say harm local wildlife, including bobcats, mountain lions, pronghorn and deer. The Tucson-based Wildlands Network released a new report this week on sites along the U.S.-Mexico border it deems most in need of environmental restoration. Traphagen, the group’s border program coordinator, traveled the international border across New Mexico, Arizona and California this and last year to identify damaged wildlife corridors and other environmental damage. The group is calling for native foliage to be replanted in areas stripped during wall construction and the spaces between the steel frames, now just 4 inches (10 cm) apart, widened to allow more wildlife to pass through. It also calls for the removal of 180 miles (290 km) of razor wire installed along pedestrian fencing in all border states in 2019 and 2020 as both an eyesore and a danger to the public and wildlife.