Power Supply Outlook Update

A snapshot of Northwest power supply and electricity demand

Columbia River Runoff volume forecast

Updated biweekly between December and July

January to July runoff at the Dalles Dam is at 136% of the 30-year average from 1981-2010.

For more narrative information, see the National Weather Service Northwest River Forecast Center. For more data including runoff history, see BPA Hydrology.

Figures in million acre-feet Low Avg High
Current forecast (2017-09-30) 137
30-year history (1981-2010) 53 101 159

Reservoir elevations and flows

Updated daily

Elevations for major U.S. reservoirs

Data for
Normal Full
Pool (ft)
Avg 10/21 Elevation (ft)
for last 10 years
Hungry Horse 3543.1 3561.0 3542.3
Libby 2441.8 2459.0 2444.4
Grand Coulee 1285.3 1290.0 1286.5
Dworshak 1517.7 1600.0 1518.2
courtesy of U of W's DART program

River flow at key Lower Snake and Columbia dams

Data for
Avg 10/21 Outflow (kcfs)
for last 10 years
Lower Granite 17.9 20.1
The Dalles 82.5 100.4
courtesy of U of W's DART program

Power flow in and out of the region

Updated daily (current period 22SEP17-22OCT17)

This shows how much average power has been imported and exported in the last 30 days.

For more information, see Bonneville's intertie analyses

IntertieAvg power flowDirection
California (AC+DC) 3,941 mw export to California
Canada (BC) -749 mw import from Canada
Total 3,192 mw export

Acronyms and glossary

  • DSI - Direct Service Industry, like aluminum processors
  • intertie - high-voltage transmission lines connecting the Northwest to other regions
  • KCFS - thousand cubic feet per second
  • load - demand
  • MAF - million acre-feet
  • MW - megawatt
  • NMFS - National Marine Fisheries Service