October to March precipitation was 33% of average—driest on record for Lee Vining and third-driest on record for Cain Ranch. The April 1 snow surveys found only 14% of average snow water content in the Mono Basin after a warm March melted much of the already near-record-low snowpack.
Based on precipitation, snowpack, and recent runoff, the Los Angeles Department of Water & Power (DWP) has run its forecasting equations and issued its runoff forecast: 19% of average runoff is expected for April–September, and 25% over the next year—assuming median precipitation falls. 2015 April–September runoff is not only going to be less than 1977, the driest year on record—it is expected to be less than half of 1977’s runoff.
We are in uncharted territory. It has not been this dry since records began in the Mono Basin. This will be a challenging year for our ecosystems and for water management.