Photo courtesy of Bonneville Power Administration
WATER FLOWS through Bonneville Dam west of Cascade Locks. BPA took stock of water conditions this spring and reported their supply is at 104 percent of usual, or normal conditions.
PORTLAND — The Bonneville Power Administration is looking at a normal water year after putting in place dry-year operations in 2015. Record-setting precipitation in December and a wet March have helped boost this year's water supply forecast.
The April 19 water supply forecast for January through July is 105.7 million acre-feet, or 104 percent of normal. The report is produced by the Northwest River Forecast Center, based on water volume measured at The Dalles Dam.
“One major difference we see this year is a more normal and evenly distributed snowpack in the Columbia Basin compared to last year,” said Erik Pytlak, manager of the Weather and Streamflow Forecasting group in BPA Power Services. "Snowpack is what feeds the system's spring and summer runoff, so it's important to BPA to have good snowpack by this time of year."
With the approaching runoff, there's a chance BPA might need to use its oversupply management protocol this year if oversupply conditions arise. The company last used that strategy in 2012. Oversupply occurs when a rare combination of factors comes together: low energy demand, an abundance of water, high hydroelectric generation and operational limitations on the amount of water that can be spilled, or passed through the dams, to protect fish.
The oversupply protocol can be triggered any time of year, but is most likely during spring runoff, even in an average water year. BPA recently received approval from the Federal Energy Regulatory Commission to use the OMP indefinitely, although BPA must still file the rate with FERC every two years. The protocol places the associated costs largely on the participating customers.
The El Niño weather pattern that the region has been experiencing since March 2015 is finally weakening, but because it was so strong, the region can expect the effects to linger for a few more months.
“Strong events like we had this past winter can bring significant precipitation to the region and result in a healthy snowpack. That has indeed played out so far this year,” Pytlak said.
BPA reported a “rather warm” winter, not only in the Pacific Northwest but across the United States. The warmer weather has been linked to lower demand for natural gas and this year's decline in gas prices. The lower gas prices have driven down the price of BPA's surplus electrical power, reducing the company’s sales outlook this year. Surplus power sales are used to keep BPA rates lower than they would have been otherwise.
On the bright side, the amount of water in Columbia River Treaty storage dams is recovering from the additional water releases made last spring and summer to offset low streamflow conditions.