The night we evac­u­ated Oroville

Popular Science - - TALES FIELD -

MATT MUR­RAY, CIVIL EN­GI­NEER/ LIAISON OF­FI­CER AT OROVILLE DAM

At 770 feet tall, the Oroville Dam, where I work, is the tallest dam in the United States and holds the sec­ond-largest reser­voir in Cal­i­for­nia. I’m from Oroville, and I was there this past Fe­bru­ary, the day the dam threat­ened to flood thou­sands of homes.

In just six weeks, storms had de­liv­ered six months’ worth of wa­ter to the re­gion. The last one hit us much more squarely than we thought it would. The reser­voir was ris­ing fast. To drain it, we had to first let it reach the top so it could run into the spill­way—the emer­gency over­flow out­let we use only for catas­tro­phes. We sent out about 20 en­gi­neers and ge­ol­o­gists to mon­i­tor po­ten­tial ero­sion on the dirt slope.

Then on Fe­bru­ary 12, one of our mon­i­tors ra­dioed that the wa­ter was de­stroy­ing the hill­side. He es­ti­mated that in an hour, the ero­sion would reach the bar­rier hold­ing back the reser­voir. If it failed, 30 feet of wa­ter would race down­hill, flood­ing sev­eral com­mu­ni­ties.

That’s when the sher­iff, who was in a con­trol room with us, took over. He said this emer­gency wasn’t about mov­ing wa­ter any­more; it was now ded­i­cated to sav­ing lives. Then he shouted, “Does ev­ery­one sup­port that plan?” The en­tire room yelled in uni­son, “Yes!”

We evac­u­ated about 188,000 peo­ple down­stream. I had 30 fam­ily mem­bers and their pets stay­ing with me. Luck­ily, the spill­way held. In the end, we cor­ralled one of the largest storms this area had ever seen. Months later, we’re still re­build­ing. We’re mak­ing half a mil­lion cu­bic yards of con­crete on-site rather than truck­ing it in so we can work faster and re­pair the dam­age by the end of the year, when wa­ter sea­son be­gins again—there is no other op­tion.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.