Dry Winters and Droughts

While we’re very hopeful that rains forecast for later this week actually happen, 90-day models are suggesting a very dry winter compared to last year. Is it too early to be thinking of conserving water and preparing for a drought? When we look at the reality of our changing climate and it’s impact on our rainfall and water supplies, we should always be in the water conservation mode!

By the time officials declare droughts and the public starts to act, we’ve already missed a lot of opportunity to make life easier in later years of prolonged droughts. Riverkeeper has been telling the community for years that we must permanently reduce water use. If we do not reduce our water use, our community will suffer in prolonged droughts that will damage our economy,  harm vulnerable species such as salmon, and increase pollution levels in our rivers.

Water conservation is the lowest-cost solution to protecting our economy and wildlife from droughts, but is a fleeting opportunity. If we are not ready to reduce use at the first signs of low rainfall, we will exhaust water supplies before the end of a drought period.

Another emerging trend is that less rain will fall in mid-sized rain events and far more will fall in deluges like last February, leading to wild swings in water supply. This graph illustrates the predicted change in various intensities of rain events. The graph shows that rain events from 10-80th percentile (roughly 0.10 to 1.5 inches of rain) will decrease significantly and deluges over 3 inches per day will dramatically increase. Rainfall will become more volatile with fewer days of heavy storms. This, combined with studies showing that droughts will also grow in duration and intensity, tells us we’re dealing with a new normal and can’t depend on historical patterns. So we must change how much water we use and always be ready to reduce to ensure we protect our economy and environment. Water conservation in California is a requirement given our changing climate.