Grant Line Canyon Near Tracy Flow Report
As of August 2, 2026, Grant Line Canyon Near Tracy is flowing at 2,010 cfs with a gage height of 4.85 ft, receding 24% over the past 24 hours. Source: USGS gauge #11313240, refreshed throughout the day.
Historical Data
Grant Line Canyon Near Tracy at a glance
How Grant Line Canyon Near Tracy is running right now, where it sits on the map, and the key gauge stats.
Grant Line Canyon Near Tracy is flowing at 2,010 cfs, with the water sitting 4.85 ft at the gage. Flow is down 24% since yesterday as the gauge recedes.
This is USGS gauge #11313240 in California. Over the past 10 days the average has been 2,129 cfs, peaking at 2,890 cfs.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the California flow report.
Engineering Data
Flow-duration statistics and observed peak-flow context computed from this gauge’s complete daily record (USGS #11313240).
Estimate flows at an ungauged site
Drainage-area ratio transfer from this gauge . Most reliable for hydrologically similar sites in the same watershed with area ratios between roughly 0.5 and 1.5.
Percentiles are flow-duration values computed from this gauge’s observed daily record as archived by Snoflo. Return periods are Weibull plotting-position estimates from observed annual maxima, provided as general reference context only. Always verify against official USGS NWIS records. Part of Snoflo for Engineering.
Streamflow Forecast
Over the next 5 days, Grant Line Cn Nr Tracy Ca is expected to recede from today's 2010 cfs, toward roughly 1593 cfs by 2026-08-06 (likely range 600-4227 cfs) -- drier than normal for the date.
Powered by PULSE — Snoflo’s forecast engine, trained on this gauge’s full record of storms, snowmelt, and dry spells.
| Date | Expected (p50) | Likely range (p25–p75) | vs normal | Projected stage |
|---|
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Grant Line Canyon Near Tracy
Its primary constituents include water resource managers and researchers who use the data to make informed decisions about water management. The gauge is located near several tributaries, including the Delta-Mendota Canal and the San Joaquin River. Seasonal trends in flow vary greatly, with peak flows occurring in the winter months due to rainfall and snowmelt. The hydrology of the area is impacted by several dams, including the New Melones Dam and the Don Pedro Dam. One interesting fact is that the San Joaquin River was once the southernmost habitat for salmon in the world.
Nearby streamflow levels
Cross-check Grant Line Canyon Near Tracy's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Grant Line Canyon Near Tracy Ca | 2,010 cfs |
| Middle River At Middle River Ca | 6,800 cfs |
| Old River A Bacon Island Ca | 6,500 cfs |
| Marsh Creek A Brentwood Ca | 0 cfs |
| Old River A Quimby Island Near Bethel Island Ca | 2,760 cfs |
| Dutch Slough Below Jersey Island Rd A Jersey Island | 5,140 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Grant Line Canyon Near Tracy. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Knights Ferry 5.2 Wsw | 0 in |
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Grant Line Canyon Near Tracy in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Grant Line Canyon Near Tracy crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Grant Line Canyon Near Tracy
What is the Grant Line Canyon Near Tracy flow rate right now?
As of August 2, 2026, Grant Line Canyon Near Tracy is flowing at 2,010 cfs. The live value, gage height, and 24-hour trend are shown at the top of this page.
Is the Grant Line Canyon Near Tracy running high or low right now?
Check the percent of median figure on this page: above 100% means Grant Line Canyon Near Tracy is running higher than normal for the date, below 100% means lower. The 24-hour trend shows whether it's rising or falling.
Where does the streamflow data for Grant Line Canyon Near Tracy come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 11313240. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Grant Line Canyon Near Tracy rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Grant Line Canyon Near Tracy report
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