The end of January -midway into the western U.S. water season–is a good time to evaluate potential water resources for the upcoming summer.
There had been some concern that an El Nino winter would result in drought conditions for some and flooding for others. Fortunately, such fears do not appear to be realized.
Let us begin by reviewing the all-important reservoir levels in California, whose low values two years ago were a cause of great concern.
As shown below, California’s reservoir levels are in excellent shape and generally well above normal. The largest and most important reservoirs (Shasta and Oroville) are at 121 and 131% of normal, respectively. Other reservoirs are also in good shape.
Moving north, what about the water levels behind the all-important Grand Coulee Dam in Washington State? As shown below, water leves are above normal. Good for power generation and fish.
Seattle’s reservoir levels?
In December they had fallen substantially below normal, but four days ago (Jan 22, shown below) were just below normal. Recent rains have brought reservoir levels up to nearly normal. With the certainty of substantial rains during the next weeks and a near-normal snowpack for the relevant mountain drainages, Seattle should be in good shape waterwise for this summer.
What about the current snowpack in the Northwest?
Over Oregon (below), with the entire state averaging a bit over 100%.
Washington (below) is currently a bit below normal, with the critical Cascade watersheds around 80%– a far better situation than a month ago. The Yakima drainage is at 91%.
The next week should be very wet along the West Coast. First, the Pacific Northwest and British Columbia will be hit by a series of moderate atmospheric rivers (see the European Center total precipitation forecast through Monday afternoon below.)
And then the atmospheric hose will move down into California, with the four-day total ending next Saturday being quite impressive from southern Oregon to Baja California.
In short, the water situation for most of the West Coast looks relatively favorable in general.
But that is not to say that there are some areas we are watching carefully. For example. the Yakima River storage is only about 60% of normal (see below). But with the Yakima drainage snowpack at 91% and lots of precipitation coming, one can be optimistic that the situation will improve.
Yakima Reservoir Levels
Finally, with El Nino starting to weaken rapidly, its impacts should begin to fade during the upcoming months.
