Does one wet winter end a drought? Not really. In 1991 our Valley was still experiencing the effects of a drought that began in 1988. The winter of 1991 brought very little rain during the usually wet months of December, January, and February. It was yet another dry winter going into March, and water managers were poised to implement a further ratcheting up of already severe water rationing mandates.
What is now referred to as a miracle occurred the first week of March 1991. Back-to-back storms boosted rainfall totals to 23 inches of rain. The miracle provided a reprieve from more severe rationing, but did not cause Cachuma to fill up and spill over, not even close. In fact, the lake did not fill and spill until two winters later; and water use restrictions remained in place during 1991 and 1992.
Generally, drought has been defined in our Valley as the period between Cachuma spill events. Using that description, we are in the eighth year of record drought. With the lake projected to reach the 80 percent full level from run-off still coming down from the upper watershed, even if there is no more rain at all. It hardly seems appropriate then, to say we are still in a drought. On the other hand, we do not know if this wet winter is a blip in what may turn out to be a longer term extended dry weather cycle.
Although surface water supplies are in robust condition with two of the three Santa Ynez reservoirs full to overflowing and the third near full, there is still the other major water supply to consider – groundwater. Filling depleted groundwater basins does not occur as rapidly as does captured runoff into a dam straddling a flowing river. Once the ground is saturated, then, and only then, can water start percolating into the lower depths of groundwater basins.
In a timelapse of pictures taken since 2017, by a Cachuma Lake webcam, the reservoir fills to the current level. With rainfall approaching 150…
Things tend to happen slowly when it comes to the underground. Water levels drop slowly (relatively speaking), and they recover slowly, sometimes taking more time to rise than they did to decline. Historically in the Santa Ynez Valley groundwater levels have recovered in five or so years once a wet weather cycle sets in. The significantly above average rainfall of this current winter has started the recovery process. But full recovery can only happen if this winter is followed by a series of wet winters.
Is the drought over? Perhaps we might answer that from two perspectives: Looking from the standpoint of surface water storage, this winter has definitely broken the back of the recent period of extremely dry winters. From a groundwater standpoint, the effects of the recent drought are not nearly over, and are not going to be over for quite some time.