Jon Harvey
@jonrv.bsky.social
southwest colorado | geoscientist | professor | dad | geomorphology | lidar | landslides | rivers |
I am really curious to know how the water mark in the canyon upstream of mexican hat compares to the driftwood line used to reconstruct the 1911 flood. You can potentially hike in along the 'road' that goes up canyon from near Lime Ck to see some of that. Thanks for documenting rhe flood!
October 30, 2026 at 7:38 PM
I am really curious to know how the water mark in the canyon upstream of mexican hat compares to the driftwood line used to reconstruct the 1911 flood. You can potentially hike in along the 'road' that goes up canyon from near Lime Ck to see some of that. Thanks for documenting rhe flood!
This one is closer to Baker's Bridge. Mary and I have been working on the gravel mining problem over the summer for a side project. There were so many pits in the channel between there and Trimble! But yea, the problem just got more interesting with this development.
October 29, 2026 at 12:43 AM
This one is closer to Baker's Bridge. Mary and I have been working on the gravel mining problem over the summer for a side project. There were so many pits in the channel between there and Trimble! But yea, the problem just got more interesting with this development.
in this image you can see the ditch is now disconnected, even with 1500 cfs flowing through. it's going to take some effort to change that.
October 29, 2026 at 12:41 AM
in this image you can see the ditch is now disconnected, even with 1500 cfs flowing through. it's going to take some effort to change that.
Interesting geomorphological event occurred during the Animas River's flood last week: The river broke out of a levy that had contained it since the 1970s, into an abandoned gravel pit in the floodplain. Now the river prefers its new route, leaving an important ditch without access to the river.
October 29, 2026 at 12:28 AM
Interesting geomorphological event occurred during the Animas River's flood last week: The river broke out of a levy that had contained it since the 1970s, into an abandoned gravel pit in the floodplain. Now the river prefers its new route, leaving an important ditch without access to the river.
ooh, good catch! bummer that it is out already!
October 26, 2026 at 5:02 PM
ooh, good catch! bummer that it is out already!
Updated timelapse showing the #sanjuanriver #flood arriving at the bridge near Mexican Hat, Utah. Now at 38,000 cfs. Seems like it is going to test all this USGS gear providing these images!
October 26, 2026 at 4:56 PM
Updated timelapse showing the #sanjuanriver #flood arriving at the bridge near Mexican Hat, Utah. Now at 38,000 cfs. Seems like it is going to test all this USGS gear providing these images!
I wonder what the gage ht of the 1911 crest would have been in the modern datum of that gage? In the canyon below Bluff there are driftwood deposits at ~45 ft above the typical low-flow river stage.
October 25, 2026 at 8:15 PM
I wonder what the gage ht of the 1911 crest would have been in the modern datum of that gage? In the canyon below Bluff there are driftwood deposits at ~45 ft above the typical low-flow river stage.
seems like it, especially with the now higher estimate of closer to 50,000 cfs coming this way
October 25, 2026 at 8:06 PM
seems like it, especially with the now higher estimate of closer to 50,000 cfs coming this way
Incoming #flood wave on the #SanJuanRiver is now expected to be >50,000 cfs at the Bluff gage - that is >14 ft ABOVE major flood stage. Absolutely devastating for the Navajo Nation / Aneth / Montezuma Creek / Mexican Hat / Bluff areas.
Watch the #SanJuanRiver near Mexican Hat, Utah go from ~700 to ~17000 cfs in this timelapse made from images at the nearby #USGS river gage location. Final frame is from this morning. A higher #flood peak of ~33,000 cfs is heading this way, moving through Farmington, NM as I type...
October 25, 2026 at 11:43 AM
Incoming #flood wave on the #SanJuanRiver is now expected to be >50,000 cfs at the Bluff gage - that is >14 ft ABOVE major flood stage. Absolutely devastating for the Navajo Nation / Aneth / Montezuma Creek / Mexican Hat / Bluff areas.
There was a pretty good line of storms to our east that was moving along itself in the vicinity so it wouldnt surprise me if it is a new flash. Animas Mtn was producing some big flows from a small cell today. Think the ground is still just too saturated!
October 25, 2026 at 12:52 AM
There was a pretty good line of storms to our east that was moving along itself in the vicinity so it wouldnt surprise me if it is a new flash. Animas Mtn was producing some big flows from a small cell today. Think the ground is still just too saturated!
Yes - my hunch is gobernador canyon, pump canyon, and Canon largo all flashed during the training storms to create the pulse below the dam...which would have been a story in its own right. But yea, starting to understand how the 1911 event came together...
October 24, 2026 at 10:19 PM
Yes - my hunch is gobernador canyon, pump canyon, and Canon largo all flashed during the training storms to create the pulse below the dam...which would have been a story in its own right. But yea, starting to understand how the 1911 event came together...
they're all down now, it looks like they did a manual measurement to get the ~33kcfs before reporting stopped?
October 24, 2026 at 9:56 PM
they're all down now, it looks like they did a manual measurement to get the ~33kcfs before reporting stopped?
USGS river gages dropping like flies as this insane #flood wave moves downstream on the #sanjuanriver. The gages "at Four Corners" and "near Bluff" are yet to receive the wave.
October 24, 2026 at 9:55 PM
USGS river gages dropping like flies as this insane #flood wave moves downstream on the #sanjuanriver. The gages "at Four Corners" and "near Bluff" are yet to receive the wave.
here is the raw link: waterdata.usgs.gov/monitoring-l...
San Juan River at Farmington, NM - USGS Water Data for the Nation
Discover water data collected at monitoring location USGS-09365000, located in San Juan County, New Mexico and find additional nearby monitoring locations.
waterdata.usgs.gov
October 24, 2026 at 9:51 PM
here is the raw link: waterdata.usgs.gov/monitoring-l...
Watch the #SanJuanRiver near Mexican Hat, Utah go from ~700 to ~17000 cfs in this timelapse made from images at the nearby #USGS river gage location. Final frame is from this morning. A higher #flood peak of ~33,000 cfs is heading this way, moving through Farmington, NM as I type...
October 24, 2026 at 6:02 PM
Watch the #SanJuanRiver near Mexican Hat, Utah go from ~700 to ~17000 cfs in this timelapse made from images at the nearby #USGS river gage location. Final frame is from this morning. A higher #flood peak of ~33,000 cfs is heading this way, moving through Farmington, NM as I type...
we are now up to 10,800 cfs in-town Durango, it seems like it really wants to break the 1970 record!
October 23, 2026 at 7:02 PM
we are now up to 10,800 cfs in-town Durango, it seems like it really wants to break the 1970 record!
The #SanJuanRiver is still experiencing major flooding in #Pagosa Springs ... meanwhile, over 20,000 cfs are moving downstream *below* Navajo Dam...meaning that upper flood wave affecting Pagosa isn't even contributing. crazy!
October 23, 2026 at 12:31 PM
The #SanJuanRiver is still experiencing major flooding in #Pagosa Springs ... meanwhile, over 20,000 cfs are moving downstream *below* Navajo Dam...meaning that upper flood wave affecting Pagosa isn't even contributing. crazy!
Not all gages reporting, but the #AnimasRiver is now >7700 cfs (as of 6:30 AM oct 23), which makes it the largest #flood since 2005 (so far!). Still likely to see that number rise over the coming hours.
October 23, 2026 at 12:31 PM
Not all gages reporting, but the #AnimasRiver is now >7700 cfs (as of 6:30 AM oct 23), which makes it the largest #flood since 2005 (so far!). Still likely to see that number rise over the coming hours.
I've got 3.5 inches in durango at 6500'. Looks like closer to 4-5 in the mountains!
October 23, 2026 at 6:02 AM
I've got 3.5 inches in durango at 6500'. Looks like closer to 4-5 in the mountains!
AFAIK That shows up more at the 50 yr flood than the 10...right now it looks like we are headed for a 10-yr event.
October 23, 2026 at 4:16 AM
AFAIK That shows up more at the 50 yr flood than the 10...right now it looks like we are headed for a 10-yr event.
Hermosa Creek reached a (local) peak tonight at 1980 cfs, which according to a 2024 fema flood study puts it at just shy of a 10 yr flood.
October 23, 2026 at 4:08 AM
Hermosa Creek reached a (local) peak tonight at 1980 cfs, which according to a 2024 fema flood study puts it at just shy of a 10 yr flood.
Exceeding 8000 cfs on the #animasriver is almost guaranteed at this point, which would be the highest number in 21 years. If we get to 10,000 cfs, which seems entirely possible, it will be the biggest #flood since 1970 (11,600 cfs).
October 23, 2026 at 12:05 AM
Exceeding 8000 cfs on the #animasriver is almost guaranteed at this point, which would be the highest number in 21 years. If we get to 10,000 cfs, which seems entirely possible, it will be the biggest #flood since 1970 (11,600 cfs).
i think that is accurate, especially since it's up to 1800 now!
October 22, 2026 at 11:55 PM
i think that is accurate, especially since it's up to 1800 now!
Unfortunately our neighbors in #pagosasprings are likely to see another flood on the san juan river that causes damage in their downtown area...which suffered a historic #flood from a similar event just last october. CBRFC says this one could be worse. Watching all of these rivers today.
October 22, 2026 at 5:57 PM
Unfortunately our neighbors in #pagosasprings are likely to see another flood on the san juan river that causes damage in their downtown area...which suffered a historic #flood from a similar event just last october. CBRFC says this one could be worse. Watching all of these rivers today.
Here we go! Already over 3000 cfs on the #animasriver and the rain train isn't going to be done for a while. With all the saturated soil and snow in the high country, this is going to be an event to remember in #durango.
October 22, 2026 at 5:54 PM
Here we go! Already over 3000 cfs on the #animasriver and the rain train isn't going to be done for a while. With all the saturated soil and snow in the high country, this is going to be an event to remember in #durango.