Will levees and dams hold?

 McALLEN - Hidalgo County is protected by the weakest levees in the Rio Grande Valley.

There are areas where the levees are so low that water could overtop them if Hurricane Dolly were to end up dumping a 100-year torrent once it moves out of the area, according to U.S. International Boundary and Water Commission spokeswoman Sally Spener.

The weakest levees are near Hidalgo, Mission, McAllen, Progreso and between the Hidalgo-Reynosa bridge and Retmal Dam south of Donna, Spener said Wednesday.

IBWC oversees the flood control system in Texas. A 100-year-rain has a 1-percent chance of occurring in any given year.

Spener said IBWC officials didn't know how much water would fall into the Rio Grande.

They were still trying to determine whether to divert water into the floodways into either the United States or Mexico.

And Spener couldn't say if the river levees would withstand the expected rainfall. She said the system is designed to handle the rain that accompanied deadly Hurricane Beulah in 1967, but that there are portions of the levee that could overtop with storms of a lesser magnitude.

Portions of the levees in Hidalgo County are between 3 to 9 feet below the height they should be, according to IBWC.

The last hurricane to hit the Valley was Hurricane Allen in 1980.

On Wednesday, Spener did not immediately know the condition of the dams and levees on the Mexican side of the Rio Grande or of any reports that specifically addressed their condition.

However, 1992 and 2003 IBWC reports state that more stretches of levees in Mexico than in the United States could overflow. In Mexico, danger areas are across from Peñitas to Retamal Dam and between the Los Indios Bridge and Matamoros.

Hurricane Beulah's hit on Sept. 20, 1967 dropped about 20 inches throughout the Valley in a week's time, according to IBWC data. It was the equivalent of a Category 5 storm. The region was devastated by its flood.

Hurricane Dolly hit as a Category 2 storm.

It was expected Wednesday to drop upward of 15 inches during the next few days.

IBWC has made repairs to the flood control system since Beulah, but its own reports in 1992, 2003 and 2006 still declared portions unsound and that it does not "provide adequate flood protection."

Hidalgo County and Cameron County officials have begged the federal government for money during recent years to fix the system and just started making progress within the past year. Levee repairs have either begun or are expected to begin within months on the most severe portions in both counties - too little too late some might say.

The potential for flooding was so great Wednesday that the Red Cross wouldn't set up shelters in the Rio Grande Valley until after the hurricane had passed.

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Jackie Leatherman covers Hidalgo County, Edinburg, the Delta and general assignments for The Monitor.