DWCD 2018 Outlook for McPhee and Dolores Project Irrigators
POSTED BY ERIC SPRAGUE ON FEBRUARY 12, 2018
Current forecast odds are barely enough for a full irrigation supply in 2018, with the CBRFC 50% forecast having dropped 20 KAF in the last month. Carry over storage is likely to be low and threatens the 2019 supply. More updates in early March.
| CBRFC Exceedance | Worst Case | 90% | 70% | 50% – MP | 30% | 10% |
|---|---|---|---|---|---|---|
| Forecast Inflow KAF (April - July) | 46 | 61 | 86 | 110 | 155 | 200 |
| % Supply | 77% | 82% | 95% | 100% | 100% | 100% |
| FSA Contract Allocation Inches/Acre | 17” | 18” | 21” | 22” | 22” | 22” |
MP – Most Probable, 50/50 chance, coin toss, median forecast based on historical weather & resulting hydrology.
FSA – Full Service Area, Yellow Jacket to Dove Creek (No adjustments are made to irrigation pools that could increase based on M&I lease, Class B & Water Bank)
The 30 year average April through July runoff for McPhee is 295,000 acre feet. We have the potential to collect precipitation towards the spring runoff through May.
The grim February forecast followed January’s continuing lack of snow. At the beginning of this month, there was only about 40% of the normal snow pack with a high pressure ridge is persisting over the western US, diverting the majority of precipitation to the north. Based on the current conditions the forecast only gives a 3% chance of the Dolores basin reaching average runoff this year. If the high pressure ridge breaks down in March we should see the storm track return to our area. If high pressure remains we’ll continue missing more normal precipitation.
McPhee currently has 132,000 Acre Feet of active storage that can provide nearly half of the 2018 water diversion needs for our community. This higher than normal carry over provides some insurance given the current conditions. With inflows remaining on the low end, carryover into 2019 will be low and increase the potential for future shortages.
Dolores Project Municipal supplies are not subject to shortage based on contract and/or senior water rights in some cases. This applies to MWC, Cortez, Towaoc and Dove Creek.
Contact Ken or Eric at 882-2164 #5 & #6 respectively or visit doloreswater.com.