Roza Water Users-

• Keechelus Reservoir filled over the weekend. Releases are occurring now to make space for the additional runoff and it will top off again.

• Rimrock Reservoir releases are also occurring now to make space for the additional runoff and it will top off again.

• Cle Elum reservoir has been filling rapidly this week. USBR is going to release 20,000 AF this week to make room for more inflows. It is expected to top off again.

The new helix (spiral) fish passage facility will be operational this year to get sockeye smolt out of the reservoir.  They have not been able to get out for the past two years. After three years sockeye smolt residualize and do not migrate to the ocean and will remain in the reservoir and are kokanee.

• Kachess reservoir had been projected to be about 70,000 acre feet short this season. The recent rain has helped fill much of the remaining space and it may fill late in the 2026 season. Kachess has a small drainage basin and is kept as full as possible for as long as possible during the season because it is the slowest to refill. Kachess also has much lower minimum outflows because there is very little fish habitat downstream of the dam in the Kachess River.

• USBR has been managing the reservoirs to maximize their refilling, which is normal in a drought year. 78% of the reservoir storage is on the Yakima mainstem arm.

• Even after the melt off in the past week the 2026 snowpack is somewhat better than 2015 (lowest on record) which is a positive sign.

• The attached map shows the drainage basins for the 5 reservoirs and the 84% of the basin which does not drain through a reservoir. It is a stark graphic which shows the need for additional water storage.

• There can be delays with the daily data being posted to the USBR Yakima Project website due to technical glitches. These are usually the result of tech issues at the Department of Interior’s IT hub in Boise.

• There can also be data transmission problems from the snow reporting sites, streamflow gages or the reservoirs, particularly during storm events. They are usually resolved within a day or two.

• The next official water supply forecast from USBR will come out on April 9^th. Roza’s hydrologist is preparing an update this week due to the changing conditions and longer than normal interval between the official forecasts. We will convey that info when we have it.

Scott Revell, District Manager~(509) 840-2721