The 'D' word
Southern Oregon reservoirs need some help from above, thanks to fewer storms and a low snowpack this winter
Bluebird weather and half the normal mountain snowpack have state and federal water managers already worried that Jackson County's main reservoirs may not fill by spring.
And too little water now could translate into too little water this summer to keep the Rogue River cool enough for migrating chinook salmon.
The U.S. Army Corps of Engineers this week dropped its releases from Lost Creek Lake into the Rogue to near-minimum flows in hopes of capturing as much water as possible.
Similar cuts in releases from Applegate Lake also are taking place while hydrologists switch from flood-control mode to fill-them mode at southwestern Oregon's two largest reservoirs.
At Lost Creek, the lake is just shy of its normal levels for early February, but the flows into the reservoir near Trail need to more than double quickly for the Corps to match its schedule to fill by May 1.
— Flows into the lake were 1,336 cubic feet per second Thursday and the outflows were 800 cfs. To fill on schedule, February flows must average 1,429 cfs more than the outflows.
Right now, we're a little more than half a foot below that at Lost Creek, and that looks like no big deal, said Jim Buck, the Corps' project manager here.
But without that inflow, we can lose ground quickly.
It's real safe to say that, if the trend continues with the weather we're seeing, we'll fall noticeably behind, Buck said.
So far behind that Lost Creek Lake, as of Thursday, had a 70 percent chance of filling by May — if the Corps maintains the outflow of 800 cfs through April, said Carolyn Fitzgerald, the Corps' water regulator for the Rogue Basin.
That probability could change, however, when the Natural Resources Conservation Service updates its Rogue Basin water availability estimates early next week, she said.
Though the Rogue Basin's snowpack fell to just 50 percent of average Thursday, Buck said it was too early to start talking about whether southwestern Oregon counties are looking at a drought designation from the governor's office.
We don't use the D-word casually, Buck said. I haven't necessarily heard that word yet, but it certainly is dry.
It's dry enough to have Oregon Department of Fish and Wildlife biologists concerned the two reservoirs may not capture enough water to supplement spring and summer flows needed for migrating chinook salmon.
Low flows in hot weather can trigger natural in-river diseases that can decimate chinook runs. In 1994, hot June weather after a below-average winter snowpack triggered an outbreak of a gill-debilitating disease that wiped out 59 percent of that year's spring chinook run.
Tom Satterthwaite, an ODFW researcher on the Rogue, said the scant inflows are cause for concern, but I'm concerned about those every year.
Satterthwaite noted that, in the past, wet springs have made up for dry mid-winter conditions and the reservoirs stored enough water to avert chinook die-offs.
Whether fish die in the Lower Rogue Canyon this June can depend on how much rain falls in February. If no appreciable rains hit over the next two weeks, Satterthwaite said the ODFW likely will request that Lost Creek Lake's outflows get cut to 700 cfs ' the lowest allowed in the 1962 congressional act authorizing the project.
Dropping flows by 100 cfs would save 200 acre-feet of water each day. That is the equivalent of putting a football field under 200 feet of water.
Over three months, that would save just 18,000 acre-feet of water.
It's not an appreciable amount of water, in the big picture, Satterthwaite said. But it all helps.
But help may not be on the way between today and Presidents Day.
The National Weather Service has not forecast any significant storms in the next two weeks.
We have a chance of showers over the weekend and that's it, said Larry Jacobs, a weather service spokesman in Medford. Then we're right back to where we are (Thursday).
The problem is less bleak for ranchers, orchardists and others who irrigate via the Talent Irrigation District.
TID manages water in three Jackson County reservoirs ' Howard Prairie, Hyatt and Emigrant. As of Tuesday, the trio were 64 percent of capacity. Manager Jim Pendleton told TID board members this week that the water-availability forecast was comparable to last year and that it should be an adequate supply for TID's needs.