Will Mono Lake rise in 2016?March 12th, 2016 by Geoff, Executive Director
The question for 2016: Will the winter be big enough to make Mono Lake rise? The short answer is: stay tuned to see what happens in the second half of winter. Snowpack conditions are the key to lake level forecasting, and they are currently far better than the last four drought years. But the snowpack is not yet above average for the Mono Basin.
Will water exports be allowed?
The lake level is currently 6378 feet above sea level. The rules controlling water exports to Los Angeles recognize the ecological jeopardy the lake is in when it approaches 6377 feet, and they add a twist. As usual, the lake level gets measured on April 1—if it is below 6377, no exports are allowed for the following 12 months. That part is straightforward and easy.
The twist comes in when the hydrologic modeling takes center stage. The rules mandate that water exports must stop if “Mono Lake is projected to fall below 6377 feet at any time during the runoff year of April 1 through March 31.” Making a 12-month lake level projection is routine—DWP and the Committee do it every year. But there are several techniques that are used, and thus, results can differ—that’s where things get tricky. How do we resolve differing projections, most notably if DWP’s stays above 6377 and the Committee’s does not? Is DWP willing to work collaboratively to deliver a consensus science-based projection?
To be sure the right thing happens for Mono Lake, the Committee began talking with DWP in December to review these rules and lay the groundwork for timely and productive collaboration.
February outlook is inconclusive
The Committee’s modeling analysis shows that this year’s runoff needs to be at least 80% of average to keep the lake above the critical 6377-foot level. That’s certainly achievable, especially with the snowpack measured at 90% of average as of February 1 and El Niño conditions remaining strong. But it is also possible that Mono Basin runoff could fall short of that mark, especially if some of the season’s remaining storms skirt to the north or south.
With the February 1 snowpack as a starting point, the Committee’s hydrologic analysis shows that the current odds are about 50% for staying above 6377 and 50% for falling below. But as of this writing it is too early to draw any conclusions, and the main lesson from lake level forecasting is to be prepared to handle all scenarios—while patiently awaiting the next storms to see what snowfall nature brings to the Mono Basin.
This post was also published as an article in the Winter & Spring 2016 Mono Lake Newsletter (page 3).