NUEVO LAREDO, Mexico – NUEVO LAREDO, Mexico (AP) — More than 18,000 people were evacuated Tuesday from a town in northern Mexico that was flooded after authorities opened a dam's floodgates for fear it would overflow from rains that accompanied Hurricane Alex.
Evacuees from Ciudad Anahuac, near the Texas border, were taken to shelters in nearby towns and cities, Mayor Santos Garza Garcia said. About 4,000 people were taken to schools in higher ground, he said.
The Venustiano Carranza dam, about 70 kilometers (43 miles) away, reached capacity after days of heavy rains, including remnants of the hurricane that slammed into Mexico's northern Gulf coast last week.
Garza Garcia said that to avoid overflow, 20 floodgates had been opened by late Tuesday. He said authorities hadn't been able to open six others because of electrical failures.
The mayor said the dam was releasing 600 cubic meters per second into the Salado River, a tributary of the Rio Grande.
"It was preferable having controlled flooding than having the whole town disappear," Garza Garcia said. "The situation is very critical."
Between 1,500 and 2,000 homes in the village of Rodriguez, which is separated from Ciudad Anahuac by a river, would be damaged, he said.
Authorities said they were being careful about releasing water from dams into already swollen rivers.
Sally Spener, public affairs officer for the International Boundary and Water Commission, which operates the Amistad dam, said it had tried to limit releases Monday "so that we would not exacerbate the flooding."
North of Ciudad Anahuac in Texas, officials in Laredo were preparing to close one of its international bridges before the Rio Grande crested late Wednesday or Thursday.
Bridge One, which links downtown Laredo to Nuevo Laredo, Mexico, was expected to close Wednesday night before the river crested at an expected 33 feet.
But Laredo spokeswoman Xochitl Mora said the span could close sooner because officials worried that pressure from the water flow could damage the bridge. The other three bridges linking the cities would remain open.
"Everyone left. There was a line of cars of about 3 miles (5 kilometers) along the highway to Nuevo Laredo," said Ciudad Anahuac resident Jose Requejo, who traveled with his whole family to Nuevo Laredo, where he has a home.
Luis Lobo, who drove 16 people from Ciudad Anahuac to Nuevo Laredo, said hundreds of people from Ciudad Anahuac and nearby villages left by foot and were by the side of the road.
"They are out in the open. Men, women, and children with nothing to eat," Lobo said after arriving in Nuevo Laredo.
Garza Garcia said soldiers planned to take food to those stranded near Ciudad Anahuac.
Hurricane Alex caused severe flooding in northeastern Mexico and swelled several rivers that feed into the dam. It has continued raining in the region.
Officials were also evacuating 2,000 people near the swollen Rio Escondido in the region, Piedras Negras Mayor Jose Manuel Maldonado said.
In Texas, a subdivision along the border was evacuated as the Rio Grande rose.
People left the Vega Verde neighborhood in Del Rio as more water was being released into the Rio Grande from the Amistad Lake, just upstream from Del Rio. A statement from the U.S. National Weather Service said that "flooding is worse on the Mexican side of the river."
At nightfall Tuesday, the National Weather Service reported the Rio Grande at 10.3 feet at Del Rio — 6.3 feet above flood stage. The river was expected to reach 10.5 feet early Wednesday. The weather service said the Vega Verde neighborhood would be under four feet of water if the river reached 11 feet.
At least 12 people were killed during the storm last week in the state of Nuevo Leon, where Ciudad Anahuac is located, said Gov. Rodrigo Medina. Three people remained missing.
Some 130,000 people were without water, and that did not count some communities in mountainous regions that were cut off, Medina told Televisa network. He appealed for helicopters to help reach isolated communities with water and other supplies.
Alex caused the most damage in Nuevo Leon, though it was down to tropical storm force by the time it hit the inland state.
The key business city of Monterrey saw major streets turned to rampaging rivers that gashed ravines through the pavement down to sewage lines and buried vehicles window deep in rocks and sand. The city was hit by heavy rain on Thursday that swelled the Santa Catarina river, which had been dry since 1988, when a hurricane hit the area.