Tuolumne River river
Total streamflow across the Tuolumne River was last observed at 1,791 cfs, and is expected to yield approximately 3,552 acre-ft of water today; about 10% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 18,154 cfs, with recent peaks last observed on 2023-05-26 when daily discharge volume was observed at 51,230 cfs.
Maximum discharge along the river is currently at the Tuolumne R Bl Early Intake Nr Mather Ca reporting a streamflow rate of 943 cfs. However, the streamgauge with the highest stage along the river is the Tuolumne R A Modesto Ca with a gauge stage of 36.86 ft. This river is monitored from 6 different streamgauging stations along the Tuolumne River, the highest being situated at an altitude of 3,831 ft, the Tuolumne R A Grand Cyn Of Tuolumne Ab Hetch Hetchy.
River streamflow levels
Daily aggregate streamflow across every monitored gauge along the Tuolumne River. Use the range buttons to zoom in on a specific period.
Total streamflow
Sum of all monitored streamgauges · daily
Every streamgauge along the Tuolumne River
All 6 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)▾ |
|---|---|---|---|---|---|---|---|
|
Tuolumne R A Grand Cyn Of Tuolumne Ab Hetch Hetchy
CA
USGS 11274790
|
848 | 10.76 | -3.8 | 77% | 3 | 5,580 | 3,831 |
|
Tuolumne R Nr Hetch Hetchy Ca
CA
USGS 11276500
|
298 | 4.65 | -29.0 | 81% | 34 | 9,660 | 3,498 |
|
Tuolumne R Ab Early Intake Nr Mather Ca
CA
USGS 11276600
|
411 | 13.79 | -28.2 | 109% | 33 | 10,900 | 2,443 |
|
Tuolumne R Bl Early Intake Nr Mather Ca
CA
USGS 11276900
|
943 | 5.57 | -17.8 | 87% | 13 | 11,700 | 2,205 |
|
Tuolumne R Bl Lagrange Dam Nr Lagrange Ca
CA
USGS 11289650
|
189 | 4.60 | 1.1 | 99% | 77 | 10,900 | 181 |
|
Tuolumne R A Modesto Ca
CA
USGS 11290000
|
197 | 36.86 | 2.5 | 82% | 46 | 10,700 | 42 |
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
Tuolumne River
The Tuolumne River is a 149-mile-long river that starts in the Sierra Nevada mountains of California and flows through the Central Valley before emptying into the San Joaquin River. The river has a rich history, having been home to indigenous communities for thousands of years and later serving as a vital transportation route during the California Gold Rush. Today, the river is used for agricultural irrigation and hydropower generation. It is also home to several reservoirs and dams, including the Don Pedro Dam, the New Don Pedro Reservoir, and the Hetch Hetchy Reservoir. These provide drinking water to the San Francisco Bay Area and irrigation water to the Central Valley. The Tuolumne River is also popular for recreational activities such as fishing, camping, hiking, and whitewater rafting.
Recreation along the Tuolumne River
Fishing access and paddle runs Snoflo tracks within the watershed.
Track the Tuolumne 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 Tuolumne River
Where does the data for the Tuolumne 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.