Napa Earthquake Turned Dry Creeks Wet Again

In the immediate aftermath of last month's earthquake, residents and business owners in the Napa Valley were struggling to get water, while waiting for damaged water mains to be repaired. But, as the San Francisco Chronicle reports, in some parts of this drought-stricken region, the earthquake actually brought a bit of temporary respite from water shortages.

According to the Chronicle, once-dry creek beds in the vicinity of Vallejo, Calif.,  have started flowing again. Alkaline groundwater in this area was displaced by and has made its way to the surface, adding 200,000 gallons of water every day to Wild Horse Creek, a stream that typically only hosts a tenth of that amount.

The Chronicle spoke with the USGS’ Tom Holzer, who said that the flows were unlikely to last: 

"Usually in a few weeks, maybe six to eight weeks, the creeks return to normal," he said. "There is only so much water in there. As the water table lowers, the water flow diminishes. It's like a bank account. You've just reached into the bank account and borrowed some money, but the spending spree will eventually end."

And, he said, the liquid largesse could eventually have negative consequences.

"It's an indication that the earthquake has changed the shallow groundwater system," Holzer said. "So people who have wells in the area, particularly if they are shallow wells, could find their wells going dry. That actually happened in the Loma Prieta quake."

Several other streams in the Napa, Sonoma, and Solano areas have also seen increased water flow, reports the Press Democrat. The Bay Area has a long history of groundwater disturbances post-earthquake, with documented occurrences of increased or decreased streamflow dating back to the 1860s, the paper points out. 

Mary Beth Griggs | | READ MORE

Mary Beth Griggs is a freelance science journalist based in New York City.