McPhee Release Update for Wednesday June 19, 2019
POSTED BY ERIC SPRAGUE ON JUNE 19, 2019
McPhee is currently releasing flows of 1,200 CFS downstream.
- Releases are currently expected to remain at 1,200 CFS until Friday June 21st to allow McPhee to finish filling, when releases will ramp up as necessary to balance reservoir inflows and outflows (which include both irrigation diversions and downstream releases) through the weekend and into next week (releases could turn up sooner). Currently, flows this weekend are expected to be between 1,200 CFS and 1,600 CFS, though if higher-than-expected inflows occur, that may require releases to go higher for a short time.
- Releases will remain at or above 1,200 CFS through Tuesday June 25th; however, it is possible but not guaranteed that releases may stay above 1,200 CFS through the following weekend, June 29th and 30th. More details will continue to be announced on later posts.
- When McPhee reaches approximately full, managers will begin operating releases to balance inflows and maintain reservoir elevation at full. Due to the variation in inflows caused by both diurnal shifts and unpredictable weather patterns, releases can be expected to fluctuate frequently above 1,200 CFS through the next couple of weeks.
The managed release is now winding down for the year and the seasonal recession in inflows has begun. The ramp-down from 800 CFS down to basic fishery releases is expected to start sometime around the beginning of July. If all goes as planned, it will last approximately a week, then the spill will be over. Please continue to check back on this site regularly for new updates, primarily on Mondays and Thursdays.
Another low-pressure system is expected to pass over the Dolores River headwaters early this weekend. As with the previous system, the increased cloud cover (and to a lesser extent, precipitation) will have an impact on inflows, though they are difficult to quantitatively predict. By the end of the weekend, this system is projected to be quickly replaced by a high-pressure system, which is currently expected to settle over the headwaters and remain for several days. Weather forecasts predict above average temperatures – the highest seen yet this year – and inflow forecasts by the River Forecast Center correspondingly predict an increase in inflows. It is possible inflows will reach the high 2,000’s in CFS next week.
As of Monday, all the SNOTEL sites in the McPhee drainage basin below 11,000 ft have hit zero. This means managers are now “snow blind”, and can no longer use melt rates to inform anticipated daily runoff volumes. The River Forecast Center does model the remaining high elevation snow coverage in the basin, however. Currently, effectively all the snow remaining in the model is situated above 11,000 ft, with the rest having melted out. Less than a fifth of the 800 sq. mile Dolores River watershed above McPhee is above 11,000 ft, and most of that portion is on primarily south-facing slopes. The model distinguishes between the basin upstream of the Dolores River gage at Rico and the basin downstream to McPhee. Upstream of Rico, the model estimates there is 75-80% snow coverage remaining above 11,000 ft. In the section of the basin downstream of Rico but upstream of McPhee, the model estimates there is 40% snow coverage remaining above 11,000 ft. While significant portions of snow clearly remain in other nearby basins, there is less remaining in the Dolores basin, which tends to melt out earlier than most others nearby.
If you have questions, the best way to address DWCD is through the “Contact” page of this website. Otherwise you can try calling 970-882-2164 extensions 5, 1 or 6.
Dolores Gage: https://waterdata.usgs.gov/nwis/uv?09166500
McPhee Elevation & Capacity: https://dwr.state.co.us/surfacewater/data/detail_tabular.aspx?ID=MCPRESCO&MTYPE=STORAGE
Dolores below McPhee: https://dwr.state.co.us/surfacewater/data/detail_graph.aspx?ID=DOLBMCCO&MTYPE=DISCHRG
Slickrock Gage: https://waterdata.usgs.gov/nwis/uv?09168730
Bedrock Gage: https://waterdata.usgs.gov/nwis/uv?09171100
DRBA: https://doloresriverboating.org/
AW: https://www.americanwhitewater.org/
The following are links to the American Whitewater River Inventory pages for the lower Dolores River: