The point of legal diversion...

of Castle Creek where most of the streamflow is routed into a sluice which then enters a 1.8 mile-long (2.9 km) pipe and is ultimately delivered to a farm’s irrigation headworks lower in the valley. The natural river channel is mostly dry for the next two miles until the point where excess water is returned to the creek.

Two observations: 1) It’s not exactly a healthy riparian system, and 2) blue tarps have limitless applications.

View upstream.

View downstream with the natural channel of Castle Creek off to the right.

Winter is hanging on...

in the high country with the La Sals completely immersed in a huge snow squall.

One week past the historic median peak, based on more than 40 years of record in the La Sal Mountains, the SNOTEL network reports there is 129% of the median snow water equivalent in the snowpack. Most excellent.

Slow and lingering late winter storms...

maintain the snowpack in the high country at near normal levels while misting the lower valley with light rains. Springtime approaches in the high desert.

A window to the snowy high country opens behind Round Mountain this afternoon.

Lasal Mountain (572) SNOTEL hydrograph: Black line indicates the current water year snow water content, closely following the median value (green line) based on 41 years of record at this station. Last year’s historic snowpack is represented by the purple line for comparison. (Graph from NCRS SNOTEL network.)

17 March 2024 update: This SNOTEL station now reports 119% of median SWE!

Swept into position by debris flows...

and sitting patiently for millennia, this pair of 1.5+ meter diameter sandstone boulders lie on an old alluvial fan surface below Round Mountain. These enormous clasts were likely entrained in a viscous slurry of water and sediment that moved down the steep topographic gradient, perhaps mobilized by an intense rainfall event, countless centuries ago.

And it was a beautiful - but blustery - day for a ride.

A significant dusting of snow...

dresses the high country in the La Sal Mountains in the wake of the first real winter storm of the season, with thee to six inches of accumulation being reported at the SNOTEL sites. It will be interesting to see what this winter brings after last year’s record breaker.

Click on image to enlarginate.

Periodic Spring is well named...

and very reliable, surging in 15 minute-long cycles of enormous discharge, then completely shutting down for a similarly long recharging period. This unusual and extremely rare hydrologic phenomenon is the outlet of a confined karst aquifer system hosted in the Madison Limestone. The intermittent spring lays in a deeply recessed canyon near Afton, Wyoming and requires a slow drive on a potholed gravel road and a short hike to reach.

Here is a well presented description of the spring, including an explanation of the mechanism at work: Geology of Wyoming - Periodic Spring.

Closer view of the modified spring orifice under flowing conditions. I recorded a time-lapse video of the spring over several cycles with a GoPro, tripod seen at left, and will post it here in a little bit.

UPDATED 19 September 2023: Here’s the time-lapse video of Periodic Spring through several cycles of discharge and recharge, each about 15 minutes long, shot over about 45 minutes. It’s magic!

The Colorado River discharge...

at the Cisco, Utah gaging station peaked on 19 May 2023 at about 41,000 cfs (cubic feet per second) despite the near record snowpack in the high country of Colorado this water year. It is interesting to note that last year’s peak flow of about 16,000 cfs occurred at about the same time (see hydrograph below) which strongly indicates that upstream diversions are robbing water from the main stem.

Exceptional aquifer recharge is occurring...

this spring in Castle Valley, Utah. Placer Creek is flowing all the way to its confluence with Castle Creek low in the valley, a once-a-decade occurrence, and in doing so is losing a large amount of its flow into the coarse, gravelly ground.

View upstream of Placer Creek and its distant headwaters in the Pinhook Valley, to the right (west) of Round Mountain.

View downstream of Placer Creek at the Buchanan Lane crossing.

Headcutting not flooding...

is the issue confronting some residents of Castle Valley that live in the so-called Upper 80, where the road crosses Placer Creek. The stream has been running steady for more than a week, eroding the crossing, and the Castle Valley Road Department has used large boulders and concrete in an attempt to limit headward erosion of the nickpoint across the road. This minimal approach is only a band aid solution provided that discharge in the stream does not rapidly increase.

View upstream at road crossing.

View downstream below road crossing.

Another late season snowfall...

lightly frosted the lower valley, but elevated the snowpack to 271% of median snow water equivalent in the higher mountains, a new record high for this historic water year.

Given the abundant soil moisture, the high desert is likely to pop with wildflowers later this spring.

Historic snowpack is still accumulating...

in the La Sal Mountains of southeastern Utah, with 252% of median snow water equivalent being indicated on this day, matching the previous record but occurring several days earlier in the season. And it’s not over yet, more snow is on the way in the high country, as atmospheric rivers continue to flood the region.

 
 

Here is the link to the SWE hydrograph shown above and to the NRCS SNOTEL map for real-time data.

23 March 2023 UPDATE: The day after this original post, this station is now reporting 264% of median SWE, well into historical territory.

A snowy blanket...

extends from the highest peaks to the valley bottom, the result of a winter storm that has passed through the area, dropping more than an inch of rain on Castle Valley.

UPDATE: Mid-day, after the storm. It’s lovely but terribly muddy.

Snow water equivalent time series for the LaSal Mountain SNOTEL site (link to current data). Black line is current water year while the blue line shows the previous water year. Green line indicates the median.

One inch of liquid sunshine...

fell overnight in Castle Valley. More rain continues to fall into the day, eventually turning to sleet/hail/snow, but no catastrophic flooding has occurred.

UPDATE: A total of 1.6 inches (41 mm) of rain fell in this first winter storm of the season. An outstanding start to the water year.

Flash flooding in Moab, Utah...

this week has hit the community hard, but it should not be entirely unexpected during summer monsoonal rain events. Two 100-year flood corridors converge in the heart of downtown - Pack and Mill Creeks - and flood hazard mapping shows that about 75% of the town’s center would be inundated. Increasing urban development and street-generated stormwater drainage probably exacerbated the situation.

FEMA’s flood hazard map for Moab, Utah. (Click on image to enlarge.)

Here’s more about the map shown above, including a legend and a zoomable viewer: Link to FEMA’s National Flood Hazard Service Center.

Fortunately there were no fatalities reported, just a lot of property damage. The cleanup: Image gallery at the Moab Times-Independent.