Latest Releases

This data is provisional and subject to change due to Dolores River inflow, future precipitation, weather patterns, managed release criteria and use.

5/5/16 Release Update

McPhee Downstream Release Update

May 1st CBRFC Inflow Forecast drops 15 KAF more, any Managed Release (Spill) is extremely unlikely. Unfortunately even with some snow in the mountains last weekend, the precipitation was less than normal for April and the May 1st forecast dropped an additional 15,000 acre feet. The way that works through the 2016 McPhee operations, we will not fill McPhee and there will be no spill. The runoff just didn’t show up as expected in April and McPhee remains 80,000 AF from full or down about 19 feet. We expect runoff to increase rapidly, but so will irrigation. The forecast reflects changed conditions relative to what it looked like a month ago based on precipitation and initial runoff inflows. It would take an extreme wet event, a 10% probability based on the last 30 years of record, like last May to fill McPhee & spill at this point. We will continue to monitor, but will expect the next potential boating release to be in May, 2017.

4/26/16 Release Update

McPhee Downstream Release Update

Although the upper Dolores Basin caught some of the April 15 -18 storm, the April overall precipitation fell a little below normal and the Colorado River Basin Forecast Center dropped their most likely (50% probability based on current conditions and 30 year record) by another 20 KAF. That means we need a little help, above average precipitation, over the next month to fill McPhee and make some excess water for a spill. Though the runoff has started and the upper Dolores is running up around a 1,000 CFS we have 3 to 4 weeks until McPhee gets up near full before a spill. So if the runoff comes in higher than currently forecast, we would announce a spill about one week ahead of the start and give ramping days and duration at higher flows of 1,000 to 1,200 CFS, likely about 5 days. It’s still shaping up around Memorial Day if it comes at all.

4/13/16 Release Update

McPhee Downstream Release Update

Early April has improved our weather patterns compared to March and brought some new precipitation to the mountains. Last week’s warm temperatures started the April runoff and a little rain on snow over last weekend jumped up all the local river flows and snow melt. This can be seen in the Lost Canyon gage into McPhee and the gages downstream of McPhee at Slickrock & Bedrock. All the lower snow, below the 9,000 foot elevation, appears to be melting and running off pretty close to normal patterns. This bump in river flows last weekend appears to be slowing down again, partially due to some cool weather at higher elevations and also partially due to the available lower snow having melted out.

The forecasted weekend storm looks promising and could boost inflow if it hits big in the upper Dolores as forecasts are starting to indicate. We remain working off the April 1 forecasts from the Colorado Basin River Basin Forecast Center (CBRFC). They produce a range of potential runoff probabilities based on future weather conditions through the April to July runoff period based on current conditions and past records. They do not always accurately know all local conditions including the extent of our lower snow pack in the Dolores. They generally have a plus or minus 15% on the McPhee inflows. If runoff falls on the plus side we’ll have a spill, no spill if runoff falls on the minus/low side. Next CBRFC forecast should be out on May 3. So we still need 105,000 AF to fill McPhee, at least 30 plus days of runoff, so no spill in early May. Cold, snow vs. rain & clouds vs. sun combined with our small amount of dust on snow will control how fast McPhee fills, but we should have a week’s notice before having to spill.

3/15/16 Release Update

March storms came up a little below average and the snowpack started to melt, then stopped and built back up a few tenths of SWE. The end result was the forecast drifting lower and somewhat flattening at the end of the month.

The 50% Most Probable (MP) Forecast based on April 1 snowpack came in at 250 KAF, while the 70% Forecast came in at 220 KAF. The MP at 250 KAF provides a small managed release (spill) for about a week. The 70% spill will not produce a boating release if it comes down in atypical pattern. We will not plan to start this release until the reservoir elevation is between 6920 and 6922. Today McPhee is at elevation 6895 and we do not expect to reach release levels until late in May. The runoff is just starting and will rise and fall with temperatures. Upper Dolores flows usually hit their peak near May 20, a likely time for us to reach near full if the runoff comes off normally. Temperatures, new storms or dust on snow can all affect the runoff timing.

So a small spill still remains possible. It will not be definite until later in May and will be short, 5 – 10 days max, with about one week’s notice before it starts. We will operate as a “fill in spill”, and start releases when we approach full at 6924, available on Lake Elevation tab. Runoff timing, early vs. late, along with future weather will drive the specific size and timing of any excess water spilled downstream. We will update again in several weeks close to May 1 as new information, such as precipitation, becomes available.