2019 Upper Snake River Operations Update
The following email update is from the Bureau of Reclamation, which outlines the current plan. Please keep in mind it can change on a moments notice due to changing weather and water conditions. Their preliminary thought on the Snake River Dam releases is that the releases would probably increase starting in Mid-April but are not certain yet. As soon as we get the next update we’ll share it on this page.
(Friday March 22, 2019)
Subject: 2019 Upper Snake River Operations Update
Purpose: The purpose of these Operation Updates is to provide information regarding Reclamation’s operations as the season progresses. The operations outlined in this update are based on the best data available at the time and are subject to change as new information becomes available. For additional information and resources, please visit our website at: https://www.usbr.gov/pn/hydromet/uppersnake/ .
Summary
The Upper Snake reservoir system is currently 85% full. There is a high likelihood of an increase of approximately 2,000 cfs for Palisades Dam next week. Estimates of the upcoming Heise April 1 runoff volume forecast along with precipitation forecasts will be examined further before determining flow changes from Palisades next week. If outflow from Palisades is increased next week, then increases in discharge may be made at American Falls Dam and Minidoka Dam next week. Island Park will see a small increase of 50 cfs Monday 3/25 which will increase its draft rate up to approximately 450 acre-feet per day in anticipation of an above average spring runoff. Ririe Dam will see its first discharge of the year going to a total outflow of 50 cfs on Monday 3/25 in anticipation of runoff picking up in the next few weeks. An increase at Little Wood Dam is likely next week as inflows are expected to pick up more next week. Short-range forecasts indicate below average temperatures and above average precipitation conditions across the Upper Snake and Little Wood watersheds.
Facility | % Full | Storage (acre-feet) | % of Daily Median Snowpack | Current Inflow (cfs) | Current Outflow (cfs) | Next anticipated discharge change |
Jackson Lake | 79% | 667,000 | 113% | 500 | 775 | Not scheduled |
Palisades | 82% | 985,100 | 110% | 3,000 | 5,500 | Next week to approx. 7,500 cfs |
Ririe | 64% | 51,900 | 124% | 40 | 0 | +50 cfs to 50 cfs Mon 3/25 |
Island Park | 83% | 111,800 | 127% | 500 | 650 | +50 cfs to 700 cfs Mon 3/25 |
Grassy Lake | 87% | 13,200 | 107% | 10 | 0 | Not scheduled |
American Falls | 92% | 1,534,000 | 115% | 8,500 | 9,000 | Next week to approx. 11,000 cfs |
Minidoka | 91% | 86,200 | – | 9,200 | 9,200 | Next week to approx. 11,000 cfs |
Milner | 0.9 feet below full | – | 9,200 | 8,200 | Not scheduled | |
Little Wood | 26% | 7,900 | 136% | 93 | 300 | Not scheduled |
Reservoir levels, reservoir discharge and river flows can be monitored on the USBR Hydromet page here: https://www.usbr.gov/pn/hydromet/
The Upper Snake “teacup” diagram which provides a graphical overview of system conditions can be accessed here: https://www.usbr.gov/pn/hydromet/burtea.html