San Acacia Dam handling floodwaters

Posted at: 09/16/2013 6:36 PM
By: Stuart Dyson, KOB Eyewitness News 4

The Rio Grande in central New Mexico is surging with floodwater after days of heavy rainfall. People who live along its banks are worried that it could jump its banks and cause widespread damage, but conservancy engineers say things are “pretty much under control”.

Millions of gallons of muddy water are blasting through the gates of the San Acacia Dam north of Socorro, at a rate of somewhere between 9,000 and 10,000 cubic feet per second. It’s runoff from days of rain upstream. Corky Herkenhoff farms alfalfa right beside the river.

“We’re always worried about flooding,” Herkenhoff said while joining Middle Rio Grande Conservancy District workers for an inspection of the dam. “The river is constricted here, which is a lucky thing for us because it goes faster and the river is deeper here than it is down below.”

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“Everything is pretty much under control at this point,” said Conservancy District chief engineer Leonard Utter.  “What we’re trying to do is get as much water as we can out of our system back into the river and also trying to keep the face of the dam debris-free.”

“The real danger is from trees and tree limbs and other debris that gets stuck in the dam,” Herkenhoff said. He pointed to a large cottonwood caught in a dam gate.  Floodwaters upstream tore it out of the ground by the roots.

Much of the water in the Rio Grande comes from two small streams that feed into it a few miles upriver from San Acacia. The Rio Salado and the Rio Puerco are both usually dry stream beds with just a muddy trickle from time to time. On Monday the Puerco was flowing at 7,000 cubic feet per second, running 18 feet deep beneath the old bridge at Bernardo.

“It’s crazy,” said Mary Maestas, who lives nearby at Veguita. “It’s a lot of water. It’s usually just a little trench right here. I’m not really worried about my place. I’m up on the hill so I’m not scared.”

“It’s a lot of water,” said Jake Ross, who drove up from Socorro after he heard the Puerco was flooding. “We could use it for sure, so I’m not complaining. I’ve never seen it like this. That’s why I came up here. I took off early for lunch and decided to check it out.”

The floodwaters spread out along the railroad tracks south of Bernardo, threatening to wash over the embankment. A freight train halted about a mile south of Bernardo, unable to proceed northward. Floodwaters did wash out a portion of US 60 east of I-25, forcing police to close the highway in both directions Monday morning.