following last week’s sustained rains, this irrigation system provides water to Castle Valley Farms lower in the valley from their legal diversion on Castle Creek.
The inlet to the two mile-long pipe gradually appears as the sandy gravel is excavated from the inlet flume.
occurred last night so I mounted the Bronco and headed to the 4WD ford above its confluence with the Colorado River near Dewey Bridge. Indeed, the waterway was raging with fast moving turbid and turbulent water and driving the river crossing is impossible at flood stage. The images show the river just below the peak discharge of 6,560 cfs as recorded by the USGS gaging station several miles upstream. For comparison, the spring runoff peak was only 414 cfs in April.
Bronco’s front tires are on the high water mark as the river is now slowly receding.
Look closely in the center of this wide image, across the river, and you can spy the continuation of the jeep road.
are turning the Colorado River a light mocha brown color with the slowly rising discharge in response to the ongoing weather event. Here’s the river around noon today. More rain is in the forecast and a flood watch is in effect.
View upstream into Professor Valley with the river running about 3,300 cfs.
UPDATE 23 October 2026, the following day: The Colorado River is now running 11,600 cfs at noon, the highest flow of the calendar year and more than twice the peak discharge during spring runoff. What a difference a day makes.
in the La Sal Mountains following a couple of days of light rain at lower elevation. My weather station located in Castle Valley has recorded nearly one inch (25 mm) of rain and more is forecast the next several days. It’s a good start to the 2026-2027 water year.
Making a brief appearance in the stormy high country: Green Mountain (left) and Pilot Mountain (right) are 12,160 feet (3,707 m) and 12,200 feet (3,719 m) high, respectively.
The view opened up a bit more later in the afternoon, but unsettled weather is expected to continue for a few more days.
beneath Castle Valley Drive earlier this summer did so quite easily, leaving behind a clear high water mark in the stranded flotsam. Considerable deposition of fine sediment has occurred in the bouldery rip rap, both upstream and downstream of the arch culvert.
Given the level of the high water line within the culvert, I conservatively estimate that the peak discharge through the structure was at least 300 cubic feet per second (cfs) but cannot estimate its duration.
rising and falling in my rural water well, a HOBO water level data logger is placed in the 300 ft (91 m) deep well as part of a regional project. This intelligent device stores and transmits water level data by Bluetooth, and corrects for atmospheric pressure effects. Hey, it’s the 21st century, you know.
Former colleague Dr. C. Pritchard (EWU Geology) measuring the static water level with a well sounding tape and preparing the data logger for installation.
The water level measuring tape indicates the static water level is 223 ft (68 m) below the lip of the metal collar. The data logger is the shiny metal device and will be suspended by a cable to nearly the bottom of the well, hanging slightly above the pump.
from pluvial Lake Bonneville occurred through this gap in southeastern Idaho known as Red Rock Pass. The volume of the great gush is estimated at five thousand cubic kilometers (1,200 cubic miles!) of water, released about 14,000 years ago in a catastrophic megaflood that likely lasted weeks to months and scoured the Snake River Plain in Idaho downstream from this site.
Red Rock Pass, a few miles south of Downey, Idaho on US 91. View is to the south, or upstream during the big spill. The vast expanse of Lake Bonneville would have existed on the far side of the skyline ridge, reaching across a third of Utah. Once the rising lake water began spilling across this low point along its shoreline and into the adjacent valley, a great unraveling was unleashed. The unconsolidated surficial alluvium and the underlying sedimentary rocks forming the bedrock sill rapidly eroded, much as a dam collapses when overtopped.
Red X marks the spot (near lower right) of Red Rock Pass, the spillover point for Lake Bonneville. The torrent of floodwater exiting the basin through the gap lowered the overall lake level approximately 105 m (350 feet). Map from Idaho State University.
More here about this tremendous flood from the Idaho State University: Lake Bonneville flood.
above its confluence with the Colorado River is easy to navigate if one already knows where the holes are. Drive the riffles, not the pools! It’s another mini adventure with my friend and neighbor in the Bronco with the front seat roof panels removed.
Today, about 1.5 miles (2.4 km) above the confluence with the Colorado River near Dewey Bridge, Utah, the Dolores River is flowing 135 cubic feet per second (cfs). Last year it was flowing 721 cfs and the historical median flow on this date is 1,120 cfs based on 40 years of record at a USGS gaging station a few miles upstream.
above the newly constructed monstrous arch culvert near the entrance to the community. It is astonishing that the natural streambed was not carried through the oversized rip-rap that is placed directly in the channel, choking it, rather than simply protecting the side slopes.
The natural cobble bed channel of Castle Creek versus the newly engineered channel choked with rip-rap.
with the road grade reestablished atop the new arch culvert on Castle Creek. Road paving and placement of rip-rap still remain as tasks to be completed before the main entrance to our community reopens to traffic.
It will be interesting to observe the backwater effects of the new structure and the rough, bouldery channel created by use of oversized rip-rap during future flood events. Upstream pooling of water, slower, less efficient passage of flood flow, increased deposition of fine sediments in the channel and increased bank erosion upstream are likely going to occur.
in eastern Washington are filled to the brim with water on the first week of spring.
by the Utah Geological Survey has been published and is now freely available to download. Most importantly, the report concludes: “Our major findings show that water-level trends in the valley-fill aquifer are stable, with little to no long-term decline.” That’s great news and not at all surprising.
Get your copy here, either in paper or digital format: UGS Special Study 176.
and then becomes obscured by low clouds as the latest early winter storm slowly passes, the first of which that dropped snow flurries on the valley this season. Meanwhile, the high country is off to a good start, sitting at 100% median snow water equivalent for this point in the water year.
Time series plot of snow water equivalent for the Lasal Mountain SNOTEL site.
is functioning at the newly constructed Placer Creek crossing on what should be a self-maintaining structure. Recent storms have flushed fine sediment onto the concrete stream crossing where it has accumulated, rather than being continuously transported further downstream. More sediment is perched in the channel upstream to be mobilized in the next event, but at least the stream bed can’t erode or incise deeper at the road crossing.
UPDATE: The deposited sediment has been cleared off the structure, but in doing so additional berms have been created on the downstream side of the concrete crossing. This will further impede the next flow event and cause even more sediment to be deposited across the structure. Not a very wise long-term maintenance strategy.
turned into rapidly flowing muddy torrents within minutes in response to the passing of an intense thunderstorm cell. My neighbor and I were enrolled in the Bronco Off-Roadeo driving clinic and were out on the Dome Plateau trail undergoing guided training. It was absolutely perfect conditions to demonstrate the vehicle’s capabilities and the Bronco powered right through the mud and easily ascended wet and slippery slickrock.
Owl Draw on the Dome Plateau, north of Dewey Bridge.
Why the off road training? I am about to take possession of the 2025 Bronco Badlands/Sasquatch next week in Moab that I had ordered in late June this year. I’m somewhat excited!
3 November 2025 UPDATE: The Bronco has landed in Moab and is being prepped by the dealer.
on the columnar basalt bedrock mark the seasonal variation of water levels in the wetlands, indicating small but significant changes in the system through time.
and summertime storm clouds blossom over the high La Sal Mountains. Less than two weeks until the summer solstice.
UPDATE: Peak flow on the Colorado River has likely just occurred, capping an unremarkable spring runoff. Here’s the one year hydrograph for the Colorado River at the Cisco gage showing that this year’s peak flow (blue line) is one-third of last year’s value (brown line) and less than half the median value (dotted line).
of legally diverted water from Castle Creek, now being performed digitally and remotely since the Utah Department of Natural Resources has just installed a real-time monitoring point using a solar powered sonic water level sensor and radio transmitter. Previously, someone would have to visit this site and visually read the staff gage in the Parshall flume through which the water is flowing in order to calculate the flow. This new system is undoubtedly calibrated to the old staff gage, and likely radios the data in real-time, or perhaps daily.
Newly installed electronic gaging station next to Castle Creek above the town of Castle Valley. Note the metal Parshall flume box through which the water is flowing, away from the viewer in this image.
The sonic water level sensor at the upstream end of the Parshall flume. Note staff gage on side of flume.
The diverted water is claimed under three water rights granted in 1885, 1891 and 1933 for 2.0, 1.033 and 1.9172 cfs (cubic feet per second) respectively according to Utah DNR records.
UPDATE: An additional remote water gauging station has been installed on the 14-inch diameter iron pipe that transfers water from the point of diversion to the fields for irrigation lower in the valley. This is about 1.1 miles below the point of diversion seen above.
in the low country has bolstered the snowpack in the high country, now standing at 76% of the median snow water equivalent, following very closely the trajectory of the 2022 water year.
This year’s snowpack (black line) compared with 2022 (green line).
as the median snow water equivalent climbs to 102% on Saint Patrick’s Day. Seems appropriate.
The luminous La Sals above Fisher Towers.
Back to median snowpack, with two weeks to go until the peak.