[4] Water Supply Forecast Dropped Fast

Despite more precipitation in much of the Columbia Basin during January after a semi-dry, cold December, the latest water supply forecast dropped precipitously over the past few weeks.

The February final forecast (released Feb. 5) from NOAA's Northwest River Forecast Center pegged the supply at only 74 percent of average for the January-July period at the Columbia River near The Dalles (about 77 million acre-feet). That was down from an 81-percent-of-average forecast just two weeks before, an 11-percent decline.

Better snowpack in northern drainages still can't make up for the lack of snow further south. The January-July forecast for the Columbia above Grand Coulee is now 81 percent of average, down from 89 percent.

The drier conditions have federal agencies scrambling. BPA announced Jan. 29 that it expects to lose $6 million for the fiscal year ending Sept. 30. Last October, it was expecting to be $232 million in the red.

"Without water, the federal hydro system is like a car with a huge engine but no gas," said Michael Milstein, BPA spokesman, in a press release. "There is still time for the snowpack to build. Twice in the last 10 years, we have had 'miracle March' snows that brought the system back from the brink."

But the statement also noted that the current forecast was likely to hold because of the El Niño weather pattern now in place, and would make this year's precip levels the lowest runoff since 2001 and 13th lowest since 1928. A dry 2010 would also put runoff below average in 10 of the last 11 years.

In 2001, Columbia Basin snowpack averaged only 53 percent and the water supply ended up about 55 percent of the long-term average, around 68 MAF.

But the region's worst water year came in 1977, on the heels of a powerful El Niño, when the basin only coughed up 53 MAF.

BPA said the expected lack of water was the sole reason for the negative revenue forecast, noting that expenses were below start-of-year budgets and the price of the electricity it sells on the surplus market was close to expectations. Without water, the federal hydro system is like a car with a huge engine but no gas.

Other federal agencies have begun conversations about what to do about salmon migration from Idaho this year, said Ritchie Graves, supervisory fish biologist with NOAA Fisheries' hydropower division in Portland.

With only a few sites in northern Idaho recording close-to-average snow levels, the water supply looks like it will be a lot worse in the rest of the state. Inflows into Dworshak Reservoir in the Clearwater watershed are only expected to be 65 percent of average.

That is close to the 64-percent-of-average water supply expected at Lower Granite Reservoir on the Snake, the first project where juvenile fish are barged. Further up the Snake, Brownlee inflows (April-July) at the Hells Canyon Project are estimated to be only 48 percent of average, down from a 52-percent estimate in December.

NOAA's Graves said tribes and other sovereigns will also be brought into the conversation as part of the new regional process called RIOG [Regional Implementation Oversight Group] developed under the 2008 hydro BiOp.

The BiOp calls for increased fish barging under low flow conditions in the Snake River, but that would run counter to the court-ordered spill regime in place until Federal District Judge James Redden makes a decision whether to uphold the salmon plan.

NOAA Fisheries has told the judge it will decide spill and transportation strategies on a yearly basis, rather than the 10-year plan outlined in the BiOp, which under average flows and more, calls for curtailing all spill at collector projects and maximizing barging for two weeks in May.

Most state and tribal managers agree in principle that when flows are really low, fish transportation should be increased, but that doesn't mean they will actually vote to shift strategies. In 2007, when fish managers had a 93-percent-of-average water supply, but faced low flows from a recalcitrant snowpack, they turned down a recommendation by NOAA Fisheries to maximize fish transportation in the Snake River for the rest of the spring.

With reduced flows expected after the 2007 freshet's spike, the agency said fish would be better off in barges than facing poor inriver migration conditions.

The NOAA Fisheries document that accompanied the recommendation said the 2002 water year was comparable to the 2007 flows, and transport smolt-to-adult survival rates (SARs) for wild chinook were four times higher than inriver fish for the late May period in that year. In 2002, the February water supply forecast was 85 percent of average.

In 2002, steelhead SARs were better for barged fish; 1.5 to 3 percent versus less than 0.4 percent for inriver migrants.

In 2007, spring average flows at Lower Granite were expected to be around 72 kcfs, about 10 kcfs below average. According to Graves, if the current forecast plays out, then spring flows at Lower Granite will likely be below 65 kcfs this year, which is the 2008 BiOp's threshold for beginning barging on April 3 and continuing it until the end of May.

It will be up to RIOG members to decide this year's barging strategy, but they probably won't make their decision until the final water supply forecast is released April 7. A recent NMFS review of transportation found that, even with the court-ordered spill regime in place, 2007 wild juvenile Snake River steelhead that were barged survived to adulthood at least two to four times better than inriver migrants, if they were transported after May 1.

Meanwhile, other Northwest watersheds aren't facing such dry conditions. The Skagit in the North Cascades is projected to be 80 percent of average, while the Cowlitz is at 83 percent. Libby inflows in western Montana are pegged at 75 percent of average in the latest forecast and Oregon's Willamette Basin is estimated at 85 percent of its average water supply from April through September. -B. R.

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