The Federal Water Master's office for the Truckee River Operating agreement (http://www.troa.net/) issues water supply forecasts near the middle of each month. The Truckee River's upstream reserves have declined steadily since February, 2015, with a well below normal snowpack and reservoirs, including Lake Tahoe, which are likely to yield nothing as a short irrigation season begins. As an example, compare the projections from January and April 2015 for water surface elevation and releases from Lake Tahoe for calendar year 2015.
January's projections indicated a 50% chance that the water surface elevations would be at the natural rim for about a month (mid-May to mid-June). This is important because Tahoe, as a large natural reservoir, sustains flow in the upper Truckee River (Tahoe City to Truckee). By April 15th, projections indicated that the probability of having water surface elevation reach the national rim dropped to about 30%, for less than a month. Accordingly, the projected releases from the lake dropped from a peak release of about 15,000 acre feet in mid-July (with a 10% probability of happening) to a peak of about 250 acre feet in mid-July (with a 30% chance of happening).
This means overall a low lake level, low flows in the upper Truckee, and diminished water supplies all the way through the Truckee River system for the summer and the critical irrigation season. The consequences? Limited access for boat launching in the lake and in upstream storage reservoirs, no recreational opportunities in the river, early termination of irrigation supplies, even in the ditches that have senior water rights. Overall, lots of effects that won't be noticeable right away, but will be easy to see by the end of the summer of 2015.
For more information on strategies for coping with water shortage see www.LivingwithDrought.com.
More, later.
