Rivermatics

2 USGS Streamgages · New York Slough system

Sf San Joaquin River flows and levels

Sf San Joaquin River is gauged at 2 USGS streamgages in California, each tracked by Rivermatics. It feeds the South Fork San Joaquin River. It drains into the New York Slough system. Drainage area at the gauges ranges from 175 square miles at SF San Joaquin River Ab Hooper C near Florence Lake, CA up to 184 at SF San Joaquin River below Hooper C near Florence Lake, CA. The gauged reach falls about 261 feet, from 7,210 feet down to 6,949.

Gauges on this river, upstream to downstream

Ordered by drainage area, which is how far down the river each gauge sits. April and July figures are long-term median daily flows for that month from the USGS record — historical normals, not a forecast and not today's reading.

USGS streamgages on this river, ordered upstream to downstream
Gauge State Drainage sq mi Elevation ft April p50 cfs July p50 cfs Forecast
SF San Joaquin River Ab Hooper C near Florence Lake, CA CA 175 7,210 26.4 30.2 —
SF San Joaquin River below Hooper C near Florence Lake, CA CA 184 6,949 29.3 30.4 —

Typical flow by month at SF San Joaquin River below Hooper C near Florence Lake, CA

The furthest-downstream gauge on this river, so the fullest flow it carries here. Long-term daily discharge percentiles from the USGS record (up to 50 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 12.6 17.3 26.7
February 12.3 19.1 31
March 15.1 24.2 41.5
April 16.5 29.3 55.5
May 22.4 37.3 118.5
June 21.9 37.7 1,904
July 22.2 30.4 957.5
August 21.6 28.5 64.1
September 21.4 27.9 38.9
October 13 18.8 34.8
November 12.1 16.2 30.8
December 12.3 16.5 25.6

All values in cubic feet per second (cfs).

Common questions

When does the Sf San Joaquin River run highest?
June, on the long-term record at SF San Joaquin River below Hooper C near Florence Lake, CA — the furthest-downstream gauge Rivermatics tracks on this river. Median daily flow there is about 37.7 cfs that month, against 16.2 cfs in November, the lowest. Upstream gauges peak on their own schedule; the table on this page gives April and July for each.
How many gauges are on the Sf San Joaquin River?
Rivermatics tracks 2 USGS streamgages on the Sf San Joaquin River, across California. Each has its own page with the site's full flow record and monthly normals. The river may carry other gauges that publish neither daily values nor discharge statistics; those are not tracked here.
What river system is the Sf San Joaquin River part of?
The Sf San Joaquin River drains into the New York Slough system — it is a tributary somewhere in that chain, following the flowpath down to its terminal river. Rivermatics builds this from the USGS/geoconnex reference-mainstem network rather than from names.
Can I use Sf San Joaquin River data for flood or safety decisions?
No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.

Other rivers in the New York Slough system

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