We are certainly in a serious statewide drought here in California. It looks like the driest stretch in about 500 years, and it is without doubt the driest since records have been kept – 150 years or so in most locations. There have been historical super droughts that can be seen in tree ring records that have been 10-20 years in length, but that’s just too scary to even contemplate.
It needs to be borne in mind that local conditions and resources are extremely important. Just look at local municipalities in our county. Cambria, a small coastal hamlet to the north of us is on track to be pretty much out of water in late spring or early summer, the City of San Luis Obispo on the other hand has a seven and a half year supply at the moment. Different areas of the state have been more or less proactive about both conserving and storing water so the effects are varied. Mostly urban water will be prioritized, and no one expects that major city supplies will run dry. Very small towns may struggle, but will in general find solutions. Agriculture is another story. Ag uses about 80% of the water in California. Much of that is used in historically arid and warm interior areas where canals and pipe systems bring water specifically for crop use. A lot of these interior ag areas served by Federal and State water projects are in for a rough year. Recent rains in Northern California have helped the Sierra snowpack, but it is unlikely it will reach average this year.
Viticulture in general is conservative in its use of water compared to other crops. Grapevines are naturally drought tolerant, I personally worked with a dry farmed vineyard through the last major drought in ‘86-92, and that vineyard survived just fine. Grapevines use far less water even when fully supplied than most other crops. They use about a ¼ of what row crops use for example. Winegrowers in coastal areas have used drip irrigation for years, which is the most efficient system from a water conservation point of view.
Here most locally we depend on underground aquifers for our water. The Edna Valley has a relatively shallow aquifer, but it recharges easily because of the large area of hills around it that drains down into it. This aquifer had been in good balance for a long time. Unlike Paso Robles just north of us where the aquifer has been overdrawn for many years before the current drought.
We had to put winter irrigations on this year to keep the roots moist which is unusual, but the aquifer is in good shape at the moment. We can expect more rain for the next 4-8 weeks after which we will assess the situation. We do not absolutely need more rain in order to irrigate the vines, but we do need rain to flush out the soils and refresh them. When you irrigate salts tend to build up in the top layer of the soil. This has to be carried out of the root zine by rainfall. There’s virtually no way for us to flush the soils ourselves using irrigation. Only generous rainfall will accomplish this.
Water conservation is one aspect of our green and sustainable initiatives here at Tolosa. It was the first practice we put into place many years ago. Every drop of water that the winery uses is treated through a three pond system until it is clean enough to be returned to the vines.
– Tolosa Winemaker, Larry Brooks