The river at Guerneville more than doubled within the same week. The public gauges that would tell us why have nothing to say.

When Sonoma Water put the upper Russian River into a “dry water supply condition” on April 16 — the first such call in years — the regional coverage looked exactly one direction: upstream. The Press Democrat, KSRO, and the water-policy daily Maven’s Notebook all filed on April 21. All three anchored on Lake Mendocino. Releases out of Coyote Valley Dam are being dialed back to hold summer water in storage. The reservoir is around 81 percent full, lower than this date last year despite a wet March. Important. Necessary. Half the story.

The other half is Lake Sonoma — the basin’s bigger reservoir, currently full, and the one about to do most of the work of holding the lower river together from now until the rain comes back in October. It’s also the half where the public has lost its window onto the dam.

A Wine Country Daily check of federal streamflow records on April 27 turned up two U.S. Geological Survey gauges directly below Warm Springs Dam — the gates Lake Sonoma releases through — that have published exactly nothing for weeks. Station 11465000, “Dry Creek below Warm Springs Dam near Geyserville,” is blank for the last 90 days. Station 11465200, “Dry Creek near Geyserville,” three miles downstream, is blank for the last 14. These are the gauges the people who actually live with this river — fishing guides, vineyard managers, Russian Riverkeeper staff, the occasional curious reporter — would pull up first thing in the morning to see what the dam is doing.

They went quiet at exactly the wrong moment.

USGS station 11467000, the Russian River at Hacienda Bridge near Guerneville, ran 605 cubic feet per second on April 19. Three days later it clocked 1,540. More than double. Over the same stretch, the next major gauge upstream — the Russian near Cloverdale — barely budged, 241 cfs to 354.

Which leaves seven hundred to nine hundred cfs that walked into the river somewhere between Cloverdale and Guerneville. On that reach there is exactly one tributary capable of moving that kind of water: Dry Creek. So it almost certainly came out of Lake Sonoma — at the very moment the public gauges below the dam stopped reporting how much.

The U.S. Army Corps of Engineers, which runs Warm Springs Dam alongside Sonoma Water, posts its own numbers on its own dashboard. At 8 p.m. on April 26, that page showed Lake Sonoma at 457.95 feet, with inflow and outflow both sitting at 67 cfs. The Corps’ working data is online. The federal science layer the rest of us cross-check it against is not.

The Press Democrat’s April 21 piece glanced at Lake Sonoma in a single sentence, noting that “a smaller change in releases for Warm Springs Dam at Lake Sonoma also is in store.” Nobody has gone back to ask how big that change actually was, when it kicked in, or what the new release profile means for the Dry Creek fishery flows the Corps and Sonoma Water are obligated to maintain under the federal Russian River Biological Opinion. Those flows exist to protect coho salmon and steelhead — populations that don’t particularly care whether Lake Mendocino is short on water this year.

Nothing on the USGS monitoring-location pages, and nothing on the broader National Water Information System status site, says when the Dry Creek gauges are coming back. Maybe the gear is down for routine maintenance. Maybe it’s a budget-driven outage. Maybe there’s a reporting change working through the system that hasn’t surfaced in agency notices yet. We don’t know. The agencies aren’t saying.

What’s on the record, and what this story is on the record about, is this: during the biggest call Sonoma Water has made on the river all year, the public can read the headline. It just can’t watch the dam.

A third gauge, USGS 11465390, the Russian River near Windsor, also came back empty — but that one is flagged “monitored seasonally” and isn’t expected to report right now anyway. The two Dry Creek gauges carry no such tag. They just stopped.

The operators’ numbers may be perfectly accurate. There is no longer a public way to know. A water system the public is asked to trust during dry years should not also be a water system the public has no way to check. Right now, on the bigger of the basin’s two reservoirs, that’s exactly what we have.