Napa River river
Total streamflow across the Napa River was last observed at 39 cfs, and is expected to yield approximately 78 acre-ft of water today; about 69% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 57 cfs, with recent peaks last observed on 2025-02-05 when daily discharge volume was observed at 15,200 cfs.
Maximum discharge along the river is currently at the Napa R Nr Napa Ca reporting a streamflow rate of 26.6 cfs. This is also the highest stage along the Napa River, with a gauge stage of 2.78 ft at this location. This river is monitored from 2 different streamgauging stations along the Napa River, the highest being situated at an altitude of 179 ft, the Napa R Nr St Helena Ca.
River streamflow levels
Daily aggregate streamflow across every monitored gauge along the Napa River. Use the range buttons to zoom in on a specific period.
Total streamflow
Sum of all monitored streamgauges · daily
Every streamgauge along the Napa River
All 2 USGS gauges Snoflo tracks for this river, with current flow, stage, recent change, percent of normal, and the gauge's all-time min / max. Click any header to sort. Cells are heatmapped relative to the column min/max -- darker blue = higher.
| Streamgauge▾ | Streamflow (cfs)▾ | Gauge stage (ft)▾ | 24h Δ (%)▾ | % Normal▾ | Min (cfs)▾ | Max (cfs)▾ | Elevation (ft)▾ |
|---|---|---|---|---|---|---|---|
|
Napa R Nr St Helena Ca
CA
USGS 11456000
|
13 | 1.66 | 44.1 | 290% | 0 | 9,510 | 179 |
|
Napa R Nr Napa Ca
CA
USGS 11458000
|
27 | 2.78 | 18.8 | 108% | 0 | 14,400 | 56 |
Maximum streamflow discharge by year
The single highest aggregate discharge recorded each year. Spotting the multi-year trend reveals droughts vs. wet cycles long before the headline daily flow does.
Annual peak discharge
From the river's full record · one point per water year
Streamflow elevation profile
Each bubble is one gauge along the river, plotted by current streamflow (x-axis) vs elevation (y-axis), sized by gauge stage. Reading top-to-bottom traces the river from headwaters down to its mouth -- you can see flow accumulate as elevation drops.
Elevation vs streamflow
One point per monitored gauge · bubble size = gauge stage
Napa River
The Napa River is a 55-mile-long river in northern California that flows through the Napa Valley. It has a long history of flooding, and has been managed through various flood control projects. There are several reservoirs and dams along the river, including the Lake Berryessa Dam and the Monticello Dam, which form Lake Berryessa and Lake Hennessey, respectively. These reservoirs provide water for agricultural uses in the valley. The river is also a popular recreational destination for activities such as fishing, kayaking, and hiking. The river's hydrology has been impacted by human activity, including land use changes and water diversions. Restoration efforts are underway to improve the health of the river and its ecosystem.
Recreation along the Napa River
Fishing access and paddle runs Snoflo tracks within the watershed.
Track the Napa River in the Snoflo app
Set per-gauge push alerts (e.g. "alert me when flow at the Russian R Nr Healdsburg crosses 5,000 cfs"), and Snoflo's iOS app pushes the moment USGS reports the crossing.
About the Napa River
Where does the data for the Napa River come from?
Streamflow and gauge stage data are sourced from the U.S. Geological Survey (USGS) National Water Information System. The aggregate flow shown at the top of the page is computed by Snoflo as the sum of all monitored gauges along the river.
How is "percent of normal" calculated?
Today's aggregate streamflow is compared to the historical average aggregate streamflow on this calendar day across the river's full record. 100% means right on average; values above 100% indicate above-normal flow (wet year); values below indicate below-normal (dry year or drought).
Why are some gauges showing very different flows?
Gauges along a river measure flow at different points: headwater gauges read what's coming off the snowpack or mountain runoff; downstream gauges integrate everything upstream, including tributary inputs. Wide spreads usually mean a tributary is contributing significantly between gauges.
What's the elevation profile chart showing?
Each bubble is one gauge along the river, plotted by streamflow (x-axis) and elevation (y-axis), sized by gauge stage. Reading top-down traces the river from headwaters to mouth -- you can see flow build as elevation drops.
Can I get alerts when a specific gauge crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app on a per-gauge basis. Open any individual streamgauge from the table above and favorite it to set a discharge threshold.