Despite substantial help from recent rain and snow events, Army Corps of Engineers water managers are bracing for another challenging year as they work to refill 13 Willamette Valley reservoirs for the upcoming conservation season. Corps officials report the system is 53% full, which is 33% below the rule curve, as of April 21.

Entering another spring season of Columbia River basin salmon and steelhead juveniles being moved downriver with much higher spill levels at federal hydropower dams than in the past, the monitoring of results of such operations has become difficult. Higher spill is pushing tagged smolts away from detection facilities, which creates data gaps when measuring the effectiveness of more spill for fish. 

NOAA issued its U.S. Spring Outlook today and for the second year in a row, forecasters predict prolonged, persistent drought in the West where below-average precipitation is most likely.

This past December, a mind-boggling 18 feet of snowfall fell in the California Sierra Nevada Mountains! How does so much snow fall in one place in such a short period of time? One of the primary phenomena responsible for such extreme rain and snowfall, particularly in regions like the western U.S., is the atmospheric river. Like their terrestrial counterparts, atmospheric rivers carry tremendous amounts of water over thousands of miles. These aerial versions, however, often bring both severe disruption and great benefit through the heavy rain and mountain snows that they produce.

In its monthly climate briefing, National Oceanic and Atmospheric Administration climatologists this week reported a warmer than normal January in Oregon and Montana and near normal January temperatures in Washington and Idaho. February has been dry, but in March the region may see lower than normal temperatures.

The California Department of Fish and Wildlife this week announced that the Department of Water Resources will receive $1.5 million in funding for the Juvenile Salmonid Collection System Pilot Project in the McCloud Arm of Shasta reservoir. This project is the first test of a collection system that would be an integral part of reintroducing endangered winter-run Chinook salmon and other runs of salmon to their historical habitat.

The U.S. Army Corps of Engineers says a recent federal court injunction that requires the agency to take steps to protect threatened salmon and steelhead in Oregon’s Willamette River basin will cause some Corps dams and reservoirs to look different and will heighten the risk of not refilling reservoirs later in the spring.

Above average rain and snow across the Columbia River basin in December and a forecast for colder than normal temperatures and higher than normal precipitation over the next few months is offering some hope of blunting the long-standing drought in the Northwest.

Canada and the United States met on December 9 to advance talks on the modernization of the Columbia River Treaty. During this round, the United States and Canada discussed ecosystem priorities, post-2024 flood risk management, and Canada’s desire for more operational flexibility.

Some 427,000 acre feet of water was available this year from the upper Snake River to augment flows for juvenile and adult salmon and steelhead migrating in the lower river.