May 1, 2015

DIRE STRAITS: Persistent Drought Reaches Epic Proportions

On Wednesday, April 1, Jerry Brown stood on a bare patch of ground in the Sierra Nevada Mountains and announced mandatory statewide cutbacks in water use to deal with the California drought.  It is now in its fourth year and, by some measurements, is the worst drought on record.

In fact, the location picked for Gov. Brown’s announcement was obviously used because of its lack of snow.  That particular spot had no snow on April 1, which was the first time that had occurred since California began measuring snowpack more than 60 years ago.  Doug Carlson, an information officer for the California Department of Water Resources (DWR), told WG&S several days later that the exact spot where Gov. Brown was standing would typically have more than five feet of snow at that time of year.  “If this was an average year, he would have been up to his neck in snow.”

From 1941 to 2014, average snow pack was above 66 inches and there was never a year with a “zero” level as there was this year.  This just exacerbates a situation that in December, scientists characterized as the worst drought in 1,200 years after studying tree ring data.

A couple of days after Gov. Brown’s mountain visit, DWR was relaying information about the drought titled “How Bad Is It?”

Carlson said while the state did receive two major storms in December and another in February, they were rain storms that dropped very little snow.  They did a fairly good job of replenishing some of the reservoirs in Northern California at that time, but other reservoirs throughout the state did not fare well at all.  Add to all that an average statewide winter temperature that has been two degrees higher than normal, and “dire straits” is an apt description of where we stand.

An early April storm did add a few more inches of snow to the mix, which allowed Carlson to say on April 8 that the up-to-the minute snowpack forecast put the state at 8 percent of normal—3 percent higher than a few days earlier but still 92 percent below normal.  Still, it was the first time in recorded history that snowpack was less than 20 percent of normal on the first day of April.  Only two other times in history has the level been as low as 20 percent.  Unfortunately last year was one of them.  Taken together, these two years are by far the two worst snowpack years in history.  No other two consecutive years are even in the same ballpark.

Carlson said as welcome as the early April storm was, it punctuated the fact that one storm and most likely not even one year will pull California out of drought conditions.  “We need an entire year to be well above normal,” he said.

Going into this year, drought forecasters calculated that the eight northern weather stations would have to receive about 150 percent of normal precipitation to pull the state out of the drought.  Even with the heavy December rains and the good storm in February, those eight stations registered just under 33 inches as of April 1, which is about 77 percent of average.  Not so great but much better than the weather stations in the San Joaquin Valley.  The so-called Tulare stations were sitting at 43 percent of average and the Southern San Joaquin Valley stations were at 42 percent.

The rainy season is basically over, though it is possible that April could see a few more storms.  But at this writing in the middle of the month, it appears that it will also be a below-average month.  Even if rain does come, it is virtually impossible that storms are going to bring 30–40 more inches of rain, which is what is needed to fill the reservoirs.  “We are in a bad situation,” Carlson said.  “No matter what happens (the rest of this water season), it is going to be a horrible year.  We need a reversal of fortune and a very wet year to get us out of this.”

Many people are calling the current drought situation as bad as it has ever been.  While the raw precipitation data may dispute that, in many other ways that comment is an understatement.  Carlson said the last time California was in a similar drought in the 1970s, “We had 22 million people in the state.  Now we have 39 million.”

That is a 75 percent increase.  Conservation efforts and much more efficient water use means we do not need 75 percent more water, but there are more houses, more lawns and more mouths to feed.  And we do need more water than we did 40 years ago.

The higher than average temperatures are causing the snowpack to melt earlier across the entire western states, which is going to lead to other issues.  “Almost all of the West Coast continues to have record low snowpack,” Natural Resource Conservation Service Hydrologist David Garen said. “March was warm and dry in most of the West; as a result, snow is melting earlier than usual.”

Historically, April 1 is the peak snowpack.  This year, the peak came earlier.  There was little snow accumulation in March, and much of the existing snow had already melted as of the first day of April.  “The only holdouts are higher elevations in the Rockies,” said Garen. “Look at the map and you’ll see that almost everywhere else is red.”  (Red indicates less than half of the normal snowpack remains.)

It is no surprise the consequence of the early snowmelt is that Western states will have reduced streamflow later this spring and summer.  In the West where snowmelt accounts for the majority of seasonal water supply, information about snowpack serves as an indicator of future water availability.  Streamflow in the West consists largely of accumulated mountain snow that melts and flows into streams as temperatures warm in spring and summer.

With Gov. Brown’s executive order and reduction announcement in early April, at this writing water districts were still determining how they were going to comply with the mandatory 25 percent reduction goals.  The governor’s plan called on water districts to develop plans to reduce the water used by their customers.  On April 13, a board committee of the Metropolitan Water District of Southern California (MWD)recommended that the water wholesaler cut deliveries to the 26 cities and water districts it serves by 15 percent this year.  The full board was expected to approve that level of cutback when it was scheduled to vote the following day.  The water rationing plan is scheduled to take effect July 1.  This would mark only the third time in the last 25 years that drought has forced the MWD to reduce deliveries.

MWD aggressively built new storage and replenished groundwater banks over the last decade leading to record amounts of water reserves when this drought began in 2012.  Since then MWD has used 1.5 million acre-feet of non-emergency storage and now has 1.2 million acre feet in reserve.  At this usage rate, MWD would have to employ draconian cuts if the drought persists for another year.

The reductions from MWD will take the form of reduced allocations for each local district that the water agency supplies with imported water from Northern California and the Colorado River. Districts that need more than their allocation will have to pay punitive surcharges that would make the additional water as much as four times more expensive than the base amount.

In Northern California the same scenario was taking place.  The water district that serves Contra Costa County, which is the geographic link between the Bay Area and the San Joaquin Valley, announced mandatory cutbacks of 20 percent that will be enforced with water rates on excess water that can double or triple a water bill for those who do not comply.

Though Gov. Brown’s water plan is not supposed to impact agriculture with mandatory reductions, it is unclear how agricultural users within these mostly-urban Southern California water districts will deal with their ag users.