The drought isn’t making nearly as much news as it did last year, but you may have heard that the state recently allowed local water districts across the state to drop their mandatory conservation requirements.  Many of the state´s reservoirs are full, and the districts were losing money.  They are, after all, in the water selling business and sales were way down as Californians of all stripes cut their water use dramatically.
Nonetheless, some very big problems remain.  One of the biggest is climate change, which is causing the snow pack to melt faster.  Full reservoirs are great, but if all the snow melts too fast as it did this year, they won’t stay full through the summer.  This year, the snow melted so fast that dam operators had to let billions of gallons of water flow out to sea because they didn’t have any more room in the reservoirs.
Another big problem in many areas is that pumping of groundwater during the drought has caused water tables to drop dramatically.  Over the past three years, this issue received lots of attention from the press, and the general public responded with vilification.  This is unfortunate, because a majority of all the water used in the state comes from the ground.  And while there are parts of California where agriculture is abusing the local acquifer, that doesn’t mean that it can’t be used sustainably.
Here in Yolo County, the small reservoir that supplies our irrigation district received very little rain during the drought.  So farmers here did what they have always done during dry periods:  irrigate using their wells.  The water table suffered as a result, especially in 2014 when it dropped to 70 feet — the same level it reached during the drought of the 1970s.
With El Niñoś rains last winter, the local irrigation district saw an opportunity to put some extra water back into the ground.  When water levels in Cache Creek — one of the primary sources of surface irrigation water for the county — reached flood stage in March, they diverted tens of thousands of acre feet into their system of unlined canals.  Normally those canals deliver water across the county to farmers’ fields, but since it was raining, no one was irrigating.  Instead, they just filled all the canals and then let the water soak into the ground.
Right now you may be thinking, “this is a no-brainer”.  Why don’t they do this every year?  Well, until December of this year, it was against the law for water districts to divert water from creeks or streams unless it was being delivered to end users.  That was when Governor Brown signed an executive order allowing it — on a very limited basis — in response to the drought.  Yolo County was given permission to try out their idea.
Moving forward, it will be critical for our state to think outside the box on water.  While there are a handful of new reservoirs being studied, they are so expensive and controversial that we cannot plan on them to save us from a warming climate.  Meanwhile, by conserving water through new technology, agriculture is no longer recharging the acquifers to the extent that it did when flooding fields was the primary way of irrigating.  We need to find new, innovative ways of recharging the groundwater.
Sustainable use of groundwater resources fits the classic conservationist creed of ¨3 Rs¨:  Reduce, Reuse, and Recycle. Hopefully Yolo Countyś experiment will be the first of many efforts to find 21st century methods of storing rainfall in the ground for later use.