Alamosa 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 (6)
- warning: seasonal Alamosa River Above Jasper, CO: No record in Nov–Feb most years: the gauge reports seasonally, so yearly and some monthly means are missing or cover only part of the year.
- warning: gap Alamosa River Above Terrace Reservoir, CO: 7 gaps of 60+ days inside the record (3,893 days in all). Longest: Oct 1, 1927 to Sep 30, 1934 (2,557 days); Oct 1, 1918 to Sep 30, 1919 (365 days); Jul 1, 1914 to Mar 31, 1915 (274 days).
- warning: seasonal Alamosa River Above Wightman Fork Near Jasper, CO: No record in Nov–Mar most years: the gauge reports seasonally, so yearly and some monthly means are missing or cover only part of the year.
- warning: seasonal Alamosa River Below Castleman Gulch Near Jasper: No record in Nov–Feb most years: the gauge reports seasonally, so yearly and some monthly means are missing or cover only part of the year.
- warning: seasonal Alamosa River Below Ranger Creek Near Jasper: No record in Nov–Apr most years: the gauge reports seasonally, so yearly and some monthly means are missing or cover only part of the year.
- warning: gap Alamosa River Below Terrace Reservoir, CO: 1 gap of 60+ days inside the record (8,766 days in all). Longest: Oct 1, 1955 to Sep 30, 1979 (8,766 days).
Context (13)
Show 13 notes
- gap Alamosa River Above Jasper, CO: 1 gap of 60+ days inside the record (209 days in all). Longest: Oct 2, 1997 to Apr 28, 1998 (209 days).
- fallback Alamosa River Above Terrace Reservoir, CO: 57% of days come from usgs; codwr 43%, nwps 0% fill days usgs does not cover, so the source changes within the record.
- flatline Alamosa River Above Terrace Reservoir, CO: 82 runs of 30+ days at exactly the same flow: 10.0 cfs for 62 days from Dec 1, 1915; 13.0 cfs for 62 days from Dec 1, 1924; 10.0 cfs for 62 days from Dec 1, 1934. Usually an estimated period (ice, a broken gauge) rather than measured daily flow.
- fallback Alamosa River Above Wightman Fork Near Jasper, CO: 17% of days come from usgs; codwr 83% fill days usgs does not cover, so the source changes within the record.
- gap Alamosa River Above Wightman Fork Near Jasper, CO: 4 gaps of 60+ days inside the record (904 days in all). Longest: Oct 19, 2001 to Sep 30, 2002 (347 days); Nov 3, 2017 to Aug 7, 2018 (278 days); Oct 1, 2005 to Apr 30, 2006 (212 days).
- zero run Alamosa River Above Wightman Fork Near Jasper, CO: 3 runs of 60+ days at zero flow; longest 244 days from Oct 1, 2003; 218 days from Oct 1, 2002. Usually real (a dry channel or no release), not missing data.
- fallback Alamosa River Below Castleman Gulch Near Jasper: 61% of days come from usgs; codwr 39% fill days usgs does not cover, so the source changes within the record.
- gap Alamosa River Below Castleman Gulch Near Jasper: 1 gap of 60+ days inside the record (208 days in all). Longest: Oct 3, 1997 to Apr 28, 1998 (208 days).
- zero run Alamosa River Below Castleman Gulch Near Jasper: 1 run of 60+ days at zero flow; longest 191 days from Oct 28, 1999. Usually real (a dry channel or no release), not missing data.
- zero run Alamosa River Below Ranger Creek Near Jasper: 2 runs of 60+ days at zero flow; longest 223 days from Oct 1, 2003; 196 days from Oct 1, 2004. Usually real (a dry channel or no release), not missing data.
- fallback Alamosa River Below Terrace Reservoir, CO: 41% of days come from usgs; codwr 59% fill days usgs does not cover, so the source changes within the record.
- flatline Alamosa River Below Terrace Reservoir, CO: 68 runs of 30+ days at exactly the same flow: 62.0 cfs for 199 days from Oct 1, 1923; 12.0 cfs for 176 days from Oct 2, 1953; 20.0 cfs for 161 days from Nov 1, 1930. Below a dam this is usually a steady set release, which is real flow.
- ended Discontinued gauges: 4 gauges have stopped reporting: Alamosa River Above Jasper, CO (last 1999); Alamosa River Below Castleman Gulch Near Jasper (last 2001); Alamosa River Above Wightman Fork Near Jasper, CO (last 2022); Alamosa River Below Ranger Creek Near Jasper (last 2022). Their segments rest on fewer gauges after those years.
Values removed (0)
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.
None.
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 |
|---|---|---|---|---|---|
| Alamosa River Above Wightman Fork Near Jasper, CO | Alamosa-Trinchera | codwr, usgs | 1995-07-24 | 2022-07-04 | 727 |
| Alamosa River Below Castleman Gulch Near Jasper | Alamosa-Trinchera | codwr, usgs | 1995-07-10 | 2001-10-22 | 208 |
| Alamosa River Below Ranger Creek Near Jasper | Alamosa-Trinchera | codwr | 2003-06-02 | 2022-07-11 | 559 |
| Alamosa River Below Terrace Reservoir, CO | Alamosa-Trinchera | codwr, usgs | 1923-04-02 | 2026-10-26 | 4153 |
| Alamosa River Above Jasper, CO | Alamosa-Trinchera | codwr, usgs | 1995-07-17 | 1999-10-18 | 125 |
| Alamosa River Above Terrace Reservoir, CO | Alamosa-Trinchera | codwr, nwps, usgs | 1914-05-04 | 2026-10-26 | 5307 |