Officials planned to activate an emergency operations center in west Texas, where the remnants of Hurricane Norbert are expected to bring rain to already saturated areas, an official said Friday.

The storm was expected to hit Mexico's western coast early Saturday with winds of at least 100 mph. The National Weather Service issued a flood warning for the Presidio area Friday, saying that heavy rain in Mexico could cause flooding along the Rio Grande there and downriver in Lajitas.

"The reservoirs are full, so the water has to come out through Presidio," Presidio County Attorney Rod Ponton said.

Additional rain in riverside Mexican towns could mean levee breaks in Texas, he said. Last month, heavy rains in Mexico caused Rio Grande to eclipse its banks, filling a nearly quarter-mile-wide channel between levees on each side of the border.

Fearing a dam break, Mexican officials released flood waters into channels that feed the Rio Grande near Presidio and the Mexican town of Ojinaga.

A levee break flooded hundreds of acres of farmland and swamped a golf course on the U.S. side east of Presidio, about 250 miles southeast of El Paso. Emergency crews built a makeshift dam along a railroad trestle to keep the flood from reaching town, but some farmland remained under water because the water table is now saturated, Ponton said.

The highway that connects Presidio, Redford and Lajitas via the Big Bend Ranch State Park remained closed Friday after a flood last month washed away chunks of the road, Ponton said.

The International Water and Boundary Commission, the two-nation agency responsible for maintaining border levees in Texas, has been monitoring them for weeks and plans to send more people to the area. But officials don't anticipate significant new flooding until the middle of next week, Ponton said.

"This isn't like standing around watching a wreck. This is like standing around, waiting for a wreck," he said. "You know exactly where it's going to happen."

(This version CORRECTS that the flood warning is for the Presidio area, not the El Paso area.)