Roza Water Users:

• USBR has issued an April water supply forecast of 52%, which is up from 44% in early March. The low end forecast is now 40% (up from 31% in March).

• The April forecast is based on the data available as of midnight on March 31^st.

• The most recent estimate for the beginning of prorationing is sometime between April 20 and May 5 according to the hydrologists at USBR and Roza. A shutdown will not occur prior to prorationing and we will keep you up to speed as it approaches. The prorationing date is highly variable.

• Ideally we will be able to give at least 2 days advance notice, but conditions can change quickly. Please check the Roza website to stay informed. A rain event or rapid snow melt can push out the proration date further on the calendar.

• The duration of a shutdown is partly a function of the weather forecast at the time. Cooler/wetter weather could increase the length of a shutdown. Our message to water users has been to plan on at least two weeks off. The actual length may vary based on conditions at the time.

• Roza’s hydrologist forecast water supply at 47% in late March and noted that USBR’s April forecast would likely be somewhat higher because there are several variables in play with forecasted runoff patterns, snow coverage, snow depth, varying snow distribution across the basin and snow density, all of which affect USBRs official adopted forecast.

• The attached staff report to the Board for their April 14^th meeting has been updated (about 90% of the info is that same as the March 30^th version). There is a new section comparing the water supply forecast by month over the 4 most recent drought years so that you can see the trends over the irrigation season.

• A hot stretch which melts the remaining snow quickly and increases irrigation demand and starts drawing down the reservoirs, followed by drier than normal conditions in the spring/summer would be very adverse to our water supply. How the snow comes off is crucial. Fish pulses could affect supply in the weeks ahead also. On the flip side, a late shot of cooler weather with a bit of high snow could help.

• Note that the April 14^th Board meeting will begin at 9 a.m. with a joint meeting with the Selah Moxee Irrigation District Board of Directors in executive session. That session is estimated to run for 30 minutes, but it could be extended if more time is needed for the discussion. The Roza Board will meet immediately afterward in an open public session. No action can occur in an executive session.

• The next USBR forecast will be issued on May 7^th. It is likely that prorationing will have occurred at that point.

• March 2026 was very wet. Inflows to the five USBR reservoirs were the 5^th highest on record

• Snowpack below 4,000 feet elevation has virtually all melted. Snow density is 36% to 43%. When snow density reaches 47% it is very ripe and comes off quickly.

• Cle Elum Reservoir will top off again next week. Kachess may fill late in the season, which is a marked improvement.

• If you have a group of water users, large or small, who would like more detail on any of these issues or the background/historical info we are available to explain the variables, the planning process and how we adapt to them as they change.

• Roza will receive $5 million for Main Canal concrete floor replacement and $600K for Main Canal concrete sealing through the state capital budget which was signed last week. This work will occur next winter. This work will represent a major step forward on a long standing problem.

Scott Revell- District Manager, Roza Irrigation District

(509) 840-2721