Drought and deluge
Coming out of the state’s driest three-year period ever recorded, the new year launched a series of atmospheric rivers that pummeled California’s lowlands with rain, hail and violent winds, and packed the Sierra Nevada with near-record depths of snow. … Sacramento has been dealing with floods since the very beginning. The city has been identified by the U.S. Army Corps of Engineers as the greatest flood disaster risk in the U.S., with New Orleans coming in second, according to Johnson. The worst flood events in the Central Valley are usually caused by a series of cold storms that build a massive snowpack in the Sierra Nevada, which is then melted by a warmer storm system. The right conditions can cause hundreds of thousands of cubic feet per second of snowmelt to rush down the American River, reaching Sacramento within 24 hours.