Sunrise light on a grove of tufa towers emerging from the water of Mono Lake with soft green and dusty-red wild grasses in the foreground, Canada geese in the shallow water with reflections of the rocky towers, and desert hills in the distance.

2018 lake level forecast: Will Mono Lake rise or drop this year?

In April, once a new runoff year (April 1 to March 31) has begun, the Mono Lake Committee forecasts what Mono Lake’s level is likely to do over the next year. And the answer? According to our forecast, Mono Lake is likely to drop a little less than a foot.

This graph shows the range of possible Mono Lake elevations for the time period of April 1, 2018 to March 31, 2019. The “highest likely” and “lowest likely” projections are produced by Committee modeling using historical wet and dry hydrology sequences that can reasonably be expected given current conditions. Mono Lake Committee graph (click to enlarge).

To forecast Mono Lake’s level for a whole runoff year, we read the lake level gauge on April 1 to get the starting point, and then factor the runoff forecast into the equation to predict what Mono Lake might do going forward. When we read the lake level gauge on April 1 together with staff from the Los Angeles Department of Water & Power the lake was 6381.9 feet above sea level. As of April 16 the runoff forecast is 85% of average. Using those two data points, plus historical wet and dry hydrology sequences that can be reasonably expected given current conditions, our modeling indicates that the most probable lake level for March 31, 2019 is 6381.1 feet above sea level.