Thursday, April 2, 2015

California Snowpack

There has been a lot of news coverage of how California Governor Jerry Brown mandated water restrictions due to the record low snowpack. Many of the articles I've read have not done what I would consider an adequate report on the snowpack level. Most of them merely say the April snowpack is at 5% of the historic level. That is frightening enough, but there's more to the story than that. The 5% figure is for the entire range.

The April snowpack is historically the largest of the year. With a full season of snowfall behind it and the melt season not yet begun means the mountains are normally stoked with stored water this time of year. But, when the California Department of Water Resources took the April snowpack measurements they found the ground was bare below 6800 feet and there no snow at all. All total, that 5% figure translates to a mere 1.4 inches of water compared to the historic average of 28.3 inches (4.9%) for April 1. This was the lowest measurement ever made for April.

But, even this isn't the worst of it.

This is the fourth measurement the Department of Water Resources has done for the media this winter. The previous three were on December 30, January 29 and March 3. The snowpack as a percentage of the historic average on those dates was 50%, 25% and 19%, respectively. And now, 5%. This is a very bad trend.

Why the decline? After all, there were some big storms this winter. Well, not really. Northern California has recorded 76% of normal precipitation this precipitation year, which began on October 1, 2014. Central and Southern California have had 41% and 42% respectively. You don't break a drought with below average precipitation.

Also, it has been so warm the precipitation fell as rain instead of snow. Some of it was captured in reservoirs and they are much better than this time last year, but still far below historic averages (typically 60% to 75% of historic averages). Some soaked into the ground. But most was lost to runoff and evaporation. None of this bodes well for California this year. The state's wettest months of the year have already passed. There is no way the snowpack runoff can be replaced and the reservoirs and ground water are already stressed. I can't see this playing out well for anyone this year.

One of the false claims deniers keep making is that there are no climate change predictions that have come true. As I said, this is false and the record is full of things that have played out just as predicted. Unfortunately, California is now on that list. It has long been predicted that rising temperatures would result in a reduced snowpack as snow fell as rain and this would, in turn, lead to increased chances of drought. 

But, of course, if they were interested in the facts they would no longer be deniers.

1 comment:

  1. Constant GardenerApril 2, 2015 at 4:53 PM

    I was hunting feral pigs near a California reservoir in February last year. Sitting where the waterline had been, where the vegetation abruptly stopped, the water was at least one hundred feet in elevation below and 150 yards away. The reservoir, side to side, was a mile-wide "V" with a 75 yard-wide strip of water in the bottom. The boat docks lay on rock a quarter mile from the water. It was absolutely shocking.