As is common in the aftermath of earthquakes, though perhaps not widely known, new fissures in the earth can cause groundwater to come bubbling up in new places, and that's been happening all over Napa at the end of this drought-plagued summer. As the Chron reports, "Torrents of water have been flowing down Wild Horse and Green Valley creeks and another unnamed waterway in the hills southeast of Napa and northwest of Vallejo since the Aug. 24 quake."
A surprise wealth of fresh water has appeared in previously dry creek beds in Napa and Sonoma Counties as well, calling to mind the rushes of water that hit Pescadero Creek and the San Lorenzo River in the wake of the Loma Prieta quake in 1989.
The water is coming from new cracks and rock fissures that allow new springs to swell with groundwater, and the influx will likely subside in six or eight weeks.
Tom Holzer, a hydro-geologist with the U.S. Geological Survey, adds that anyone with wells in the area, especially shallow wells, should be aware that they may dry up in the coming weeks or months because of these shifts in groundwater, and lowering water tables.
But, for now, places like Vallejo are thrilled that their water supply is getting a boost.