A mid- to late-May batch of storms strafed, particularly, the upper end of the Columbia River basin to help lift water supply predictions for the spring and summer to near normal, according to the forecast posted online late Wednesday by NOAA’s Northwest River Forecast Center.

U.S. Army Corps of Engineers reservoir regulators think it’s unlikely that water levels at most of the Corps’ 13 reservoirs in western Oregon’s Willamette River basin will rise much beyond current levels -- 3 to 28 feet below their target elevations -- without significant additional rain.

Precipitation totals in April and early May strengthened a late season trend that indicates the Columbia River basin will receive near normal water runoff volumes from the north during the balance of the spring and summer while southern tier contributions, including from the Snake River, will be subpar.

The U.S. Army Corps of Engineers alerts boaters and other users of Foster Reservoir near Sweet Home, Ore., that the reservoir will be held near an elevation of 635 feet above sea level throughout the summer of 2013; about two feet lower than usual.

To allow for wider public input, the Walla Walla District of the U.S. Army Corps of Engineers is extending the public comment period regarding Clean Water Act compliance for a proposed sediment management -- dredging – to re-establish congressionally mandated depth of the lower Snake River navigation channel.

A “very large storm” pushing into the Northwest at week’s end was expected bring rain, and snow in high places, through at least the weekend, particularly on the west side of the Cascade Mountains but to the east side of the Cascades and Columbia River basin as well.

According to the NOAA’s National Weather Service, 2013 has started off as one of the driest years on record for the inland valleys of southwest Washington and northwest Oregon, which straddle the Columbia River in what is generally considered the wet side of the basin.

Low winter snowpack in key Idaho Snake River drainages, combined with lower-than-normal carryover from upstream reservoirs, should allow Idaho Power Company to maintain Brownlee Dam’s reservoir at a higher-than-normal elevation during the spring flood control period.

Salmon are beginning to swim up the Elwha River for the first time in more than a century. But University of Washington marine geologists are watching what’s beginning to flow downstream — sediments from the largest dam-removal project ever undertaken.

Geologic barriers, the intermixing of water between aquifers through wells, and groundwater pumping contribute to the pattern of declines of groundwater levels of the Columbia Plateau, according to a report published by the U.S. Geological Survey. http://pubs.usgs.gov/sir/2012/5261/

Concerns about the high cost of maintaining the shipping channel of the lower Snake River dominated an information meeting on a sediment management plan hosted by the U.S. Army Corps of Engineers Thursday in Lewiston.