San Juan River
Streamflow, conditions and background by watershed segment. Data through November 1, 2026.
Data gaps and disparities
Found automatically in the gauge records behind this river, and notes from a reviewer who checked them against other sources. Gauges need at least 26 weeks of daily data to appear on the Flow tab.
Warnings (3)
- warning: gap San Juan R At Bolack Ranch Brdg Nr Farmington Nm: 1 gap of 60+ days inside the record (946 days in all). Longest: Feb 9, 2021 to Sep 12, 2023 (946 days).
- warning: gap San Juan River At Bloomfield, NM: 2 gaps of 60+ days inside the record (20,232 days in all). Longest: May 4, 1978 to Dec 11, 2019 (15,197 days); Jan 1, 1964 to Oct 13, 1977 (5,035 days).
- warning: peak conflict San Juan River At Shiprock, NM: 5 approved USGS daily values exceed that water year's USGS annual peak, in water years 1970, 1975 (e.g. 11,300 cfs on Oct 22, 1969 against a peak of 9,010). A day's mean cannot exceed the year's peak, so one of the two USGS records is wrong for those years; the daily values are kept.
Context (7)
Show 7 notes
- ended Discontinued gauges: 3 gauges have stopped reporting: San Juan R Nr Blanco, NM (last 1954); San Juan River At Hammond Br Nr Bloomfield, NM (last 1981); San Juan R Nr Fruitland, NM (last 2025). Their segments rest on fewer gauges after those years.
- spike San Juan R At Bolack Ranch Brdg Nr Farmington Nm: 1 single-day flow far above the gauge's usual range (99th percentile 1,024 cfs) with no annual peak on record to confirm them: 6,830 cfs on Oct 22, 2026. Flash floods are common here, but these are unverified.
- flatline San Juan R Nr Blanco, NM: 1 run of 30+ days at exactly the same flow: 300.0 cfs for 31 days from Jan 1, 1932. Usually an estimated period (ice, a broken gauge) rather than measured daily flow.
- fallback San Juan River At Bloomfield, NM: 34% of days come from usgs; usbr_hydrodata 66% fill days usgs does not cover, so the source changes within the record.
- copy disagree San Juan River At Farmington, NM: The usace_cwms copy agrees on the median but differs by more than 10% on 35% of 7,820 shared days (often provisional vs approved data, or a different daily averaging window). The report takes 2 days from usace_cwms where usgs is missing, so the level can shift there.
- flatline San Juan River At Farmington, NM: 2 runs of 30+ days at exactly the same flow: 460.0 cfs for 31 days from Dec 1, 1930; 420.0 cfs for 31 days from Jan 1, 1931. Usually an estimated period (ice, a broken gauge) rather than measured daily flow.
- flatline San Juan River Near Archuleta, NM: 1 run of 30+ days at exactly the same flow: 382.0 cfs for 33 days from Nov 2, 1968. Usually an estimated period (ice, a broken gauge) rather than measured daily flow.
Values removed (19)
A reading is removed automatically only when it is impossible (for example, a daily mean above the highest flow USGS recorded that water year). Low and zero flows are never removed: rivers here really do dry up.
Show 19 removed values
| Gauge | Date | Source | cfs | Why |
|---|---|---|---|---|
| San Juan River At Farmington, NM | 2005-05-22 | usace_cwms | 18568.4 | automatic: daily mean above that water year's USGS peak of 14,400 cfs |
| San Juan River At Farmington, NM | 2005-05-23 | usace_cwms | 17631.6 | automatic: daily mean above that water year's USGS peak of 14,400 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-20 | usace_cwms | 5546.2 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-21 | usace_cwms | 6383.5 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-22 | usace_cwms | 7065.6 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-23 | usace_cwms | 7329.6 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-24 | usace_cwms | 7241.4 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-25 | usace_cwms | 6930.6 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-26 | usace_cwms | 6302 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-27 | usace_cwms | 5870.2 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Pagosa Springs, CO | 2005-05-28 | usace_cwms | 5292 | automatic: daily mean above that water year's USGS peak of 4,890 cfs |
| San Juan River At Shiprock, NM | 1969-10-22 | usbr_hydrodata | 11300 | automatic: daily mean above that water year's USGS peak of 9,010 cfs |
| San Juan River At Shiprock, NM | 1970-09-07 | usbr_hydrodata | 11300 | automatic: daily mean above that water year's USGS peak of 9,010 cfs |
| San Juan River At Shiprock, NM | 1975-06-06 | usbr_hydrodata | 10700 | automatic: daily mean above that water year's USGS peak of 9,400 cfs |
| San Juan River At Shiprock, NM | 1975-06-07 | usbr_hydrodata | 11300 | automatic: daily mean above that water year's USGS peak of 9,400 cfs |
| San Juan River At Shiprock, NM | 1975-06-08 | usbr_hydrodata | 10000 | automatic: daily mean above that water year's USGS peak of 9,400 cfs |
| San Juan River Near Archuleta, NM | 2005-05-19 | usace_cwms | 5358.4 | automatic: daily mean above that water year's USGS peak of 5,090 cfs |
| San Juan River Near Archuleta, NM | 2016-05-23 | usace_cwms | 5092 | automatic: daily mean above that water year's USGS peak of 4,720 cfs |
| San Juan River Near Archuleta, NM | 2016-05-24 | usace_cwms | 5109.3 | automatic: daily mean above that water year's USGS peak of 4,720 cfs |
Gauges
Each row is one physical gauge; "published by" lists every agency copy that was merged into it.
| Gauge | Segment | Published by | First | Last | Weeks |
|---|---|---|---|---|---|
| San Juan River At Pagosa Springs, CO | Upper San Juan | codwr, nwps, usace_cwms, usbr_hydrodata, usgs | 1935-09-30 | 2026-10-26 | 4753 |
| San Juan River Near Carracas, CO | Upper San Juan | codwr, nwps, usgs | 1961-10-30 | 2026-10-19 | 3387 |
| San Juan R At Bolack Ranch Brdg Nr Farmington Nm | Upper San Juan | usbr_hydrodata, usgs | 2019-12-16 | 2026-10-19 | 223 |
| San Juan River At Hammond Br Nr Bloomfield, NM | Upper San Juan | usgs | 1977-10-03 | 1981-10-05 | 210 |
| San Juan River Near Archuleta, NM | Upper San Juan | codwr, nwps, usace_cwms, usbr_hydrodata, usgs | 1954-11-29 | 2026-10-26 | 3753 |
| San Juan R Nr Blanco, NM | Upper San Juan | usgs | 1930-09-29 | 1954-12-27 | 1266 |
| San Juan River At Bloomfield, NM | Upper San Juan | usbr_hydrodata, usgs | 1955-10-03 | 2026-10-26 | 818 |
| San Juan River At Shiprock, NM | Middle San Juan | nwps, usbr_hydrodata, usgs | 1934-10-01 | 2026-10-19 | 4804 |
| San Juan R Nr Fruitland, NM | Middle San Juan | usgs | 2017-04-03 | 2025-12-01 | 453 |
| San Juan River At Farmington, NM | Middle San Juan | codwr, nwps, usace_cwms, usbr_hydrodata, usgs | 1930-09-29 | 2026-10-26 | 5014 |
| San Juan River At Four Corners, CO | Lower San Juan-Four Corners | nwps, usbr_hydrodata, usgs | 1977-10-03 | 2026-10-26 | 2558 |