When a big storm is coming, you'll hear forecasts like "the Russian River at Guerneville is expected to crest near 38 feet." That number is the water level at a specific river gauge, and the National Weather Service's California Nevada River Forecast Center (CNRFC) publishes what happens at each level.
Guerneville gauge (GUEC1)
The CNRFC lists these stages for the Russian River at Guerneville (CNRFC):
| Stage | Height | What the CNRFC says happens |
|---|---|---|
| Action (monitor) | 29 ft | Monitor stage |
| Minor flood | 32 ft | Lower Mill Street in Guerneville and Old Bohemian Highway in Monte Rio expected to flood |
| Moderate flood | 35 ft | Numerous businesses and residences in the lowest sections of river towns expected to flood |
| Major flood | 40 ft | Travel on River Road in Guerneville very difficult; upper Redwood Drive in Northwood floods |
| Flood of record | 49.5 ft | February 18, 1986 |
Between those stages, the impact list gets specific. At 33 feet, Highway 116 at Drake Road in Guerneville closes and Willow and Alder Streets in Monte Rio flood. At 36 feet, Mirabel Park and the Mirabel trailer park in Forestville flood. At 37 feet, Mirabel Road at River Road floods. At 44 feet, Highway 116 west of Guerneville closes. Check the live page for the full list before each storm.
Healdsburg gauge (HEAC1)
At Healdsburg, the CNRFC lists an action stage of 20 feet, minor flood at 23 feet (farmland and riverbanks), moderate at 27 feet, and major at 29 feet, when "homes, businesses and secondary roads in the lower sections of Healdsburg will begin to flood" (CNRFC).
The Laguna de Santa Rosa at Sebastopol (LSEC1)
The Laguna has its own gauge, with an action stage of 67 feet and minor flooding at 69 feet, when Occidental Road begins flooding near the channel (CNRFC). Because the Laguna drains to the Russian River, it can back up when the river is high. In February 2025, a local paper reported the Laguna rising onto part of Morris Street as the river peaked (Sebastopol Times).
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What 2019 looked like
In late February 2019, the Russian River passed flood stage at Guerneville on February 26 and crested at 45.38 feet late on February 27. Guerneville became an "island" reachable only by boat, and Guerneville and Monte Rio saw roughly 2,000 properties with some flood damage (NWS). The County's initial assessment counted about 1,900 damaged homes countywide, 1,760 of them with major damage, and estimated $155 million in damage (County of Sonoma).
How to use the numbers
- Find out how high your floor, garage and crawlspace sit compared with past floods. Long-time neighbors, the previous owner, and FEMA's Flood Map Service Center can help.
- Decide in advance what you'll do at each forecast level: move cars, raise belongings, place sandbags, leave.
- Watch the CNRFC forecast and Sonoma Water's flood information page. Sonoma Water updates its Flood Forecast Hotline, (707) 526-4768, when the Hacienda Bridge level is over 20 feet.
- Sign up for SoCoAlert so you get evacuation warnings.
After the water drops
Floodwater is contaminated. Read returning home after a flood before you start, and see flood cleanup to get connected with a licensed provider.
Dealing with this right now?Tell us what's happening and we'll connect you with an independent local provider.
Sources
- CNRFC: Russian River at Guerneville (GUEC1)
- CNRFC: Russian River at Healdsburg (HEAC1)
- CNRFC: Laguna de Santa Rosa at Sebastopol (LSEC1)
- NWS: Historic flooding across the North Bay, Feb 2019
- County of Sonoma: $155 million in flood damages (Mar 2019)
- Sebastopol Times: Sebastopol flood diary (Feb 2025)
- Sonoma Water: Flood forecast & emergency information
- FEMA Flood Map Service Center
Sources checked October 18, 2026.
Frequently asked questions
Is flood stage the same everywhere on the river?
No. Each gauge has its own stages. 32 feet means flooding at Guerneville, but Healdsburg's flood stage is 23 feet.
Where do I get the forecast?
The CNRFC posts official river forecasts for Guerneville and Healdsburg. Sonoma Water and SoCoEmergency link to them during storms.