Counting every drop...

of legally diverted water from Castle Creek, now digitally and remotely, the Utah Department of Natural Resources has just installed a real-time monitoring point using a solar powered acoustic detector 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 certainly calibrated to the old staff gage, and likely radios the data in real-time, or perhaps daily.

Newly installed water diversion 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 acoustic water level detector at the upstream end of the Parshall flume. Note staff gage on side of flume.

Several dreary and misty days...

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).

Back into the green...

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.

Nearly back to normal...

snow water content in the high country as a result of several late-winter storms this month. But the valleys remain exceptionally dry, with my gauge recording only 0.15 inches (~4 mm) of precipitation from yesterday’s storm.

Lingering clouds obscure the higher La Sal Mountains where snow is almost certainly still falling this morning.

Current SNOTEL data showing 92% median snow water equivalent in the snowpack with 18 days to go to the median peak.

Still on track to be a dry winter...

despite the recent snow and rainstorms that passed through the region.

A view of the high country with its fresh mantle of snow.

We’re only half-way to an “average” snowpack but there are still 46 days until the typical peak.

An interesting groundwater seep...

at the stratigraphic contact between the Cutler and Moenkopi Formations below Adobe Mesa bears some further examination, but it’s a difficult scramble to its location on steep and unstable slopes. Light-colored mineral deposits, likely either calcium carbonate (calcite) or calcium sulfate (gypsum), occur at the margins of the seep.

The snowpack has statistically diminished...

to only about 70% of median snow water content in the La Sal Mountains as this very dry winter season continues.

Wind-swept rocky surfaces and large snow cornices reveal a high country that hasn’t seen significant snowfall since around Thanksgiving.

Sediment aggradation will almost certainly occur...

in the ephemeral stream channel upstream of the newly installed concrete ford in Placer Creek, rather than being continuously transported across the structure when the stream is flowing. Engineers should have matched the elevation of the stream bed rather than maintain the road grade at the crossing. While this structure isn’t going anywhere in future floods, it will require maintenance after each event in clearing accumulated sediment, in perpetuity. It could have been self-maintaining, so let’s see how it performs over the next decade.

The brand-spanking-new $188,889 mega-concrete stream crossing structure on Placer Creek at the entrance of Round Mountain State Park.

The calendar year begins...

with a normal snowpack in the La Sal Mountains. But it’s been dry in the surrounding canyon country.

A window opens in the passing storm...

but very little precipitation fell in the valley nor in the high country, a bit of a disappointment. The snow water equivalent at the Lasal Mountain SNOTEL is indicated at 113% of the median.

The new off ramp to Interstate 70...

is coming along nicely in Castle Valley at Placer Creek. What folly.

Any one of these lower cost and more environmentally friendly low-water crossing designs would have worked just fine at this small and usually dry stream crossing: Chapter 5 - Low-Water Crossing Types.

A mild autumn season...

comes to a close in three days on the winter solstice and the extended forecast is for continued dry conditions with moderate temperatures. The Old Farmer’s Almanac is predicting that “precipitation and snowfall will be average or above average throughout the Intermountain Region. The snowiest periods will fall in mid-November, early and late January, and mid-March.” We shall see.

Another vibrant sunrise this morning above the La Sal Mountains. It’s good to be a morning person.

The snow water equivalent in the snowpack has flatlined since late-November, now just 121% of median.

The Culebra Cut of Castle Valley...

is being excavated at the Placer Creek dry stream crossing. Methinks this is a grossly overengineered and expensive solution to an erosion problem that no longer exists, but that’s just 40+ years of experience as a fluvial geomorphologist talking.

Meanwhile, elsewhere in the community, the drainage ditches that are choked with sediment from summer flooding go largely unattended. Pure negligence.

An outstanding early start...

to the water year in the high country thanks to a pre-Thanksgiving winter storm that dropped 1.5 inches (38 mm) of rain on Castle Valley yesterday.

SNOTEL time series showing this year’s snowpack (black line). Green line represents the median and the orange line is the previous water year for comparison.

Link to NRCS Snotel network.

These enormous imbricated boulders...

were certainly moving as bedload in this ephemeral wash below Adobe Mesa during the flash flooding events this summer. Here they now sit, shingled on top of one another, likely stranded for a decade or more until mobilized in the next extreme hydrologic event in this drainage.

As artificial as the sky and cloudscape appears in this image, it was that lovely of a day in Castle Valley.

Significant scour and fill on Castle Creek...

occurred above the bridge on Castleton Road during this summer’s flooding, clearly evident from examining these images taken three years apart. Compare and contrast.

THEN: Castle Creek on 17 November 2021.

NOW: Castle Creek on 31 October 2024.

The footprint of flood impacted areas...

throughout Castle Valley is clearly seen in the recently updated satellite imagery available in Google Earth and Google Maps. Light-colored sedimentary deposits paint the areas affected by overland sheet-flooding and where floodwaters escaped ditches and natural channels. Compare and contrast.

Imagery date: 7 August 2024.

Imagery date: 14 October 2022.

Hint: Learn to use the time slider tool in Google Earth to time travel into the past and examine earlier satellite imagery.

Episodic scouring and filling...

of the steep gradient, coarse-grained and ephemeral Placer Creek channel through time, coupled with headcutting by knickpoint migration through the stream crossing, has created a challenge in upper Castle Valley for road maintenance. Compare and contrast the conditions that existed five years ago and today.

Placer Creek crossing on 1 May 2019. Note crushed culvert and concrete on downstream side of roadway. By attempting to maintain this knickpoint in the stream profile for the long term only exacerbated the erosion that eventually occurred here.

Placer Creek crossing on 30 June 2024. Significant scour has deepened the channel once again. The knickpoint has migrated upstream and behind the two large boulders on the left.

The road crossing is now graded to a more stable position in the short term, at the same elevation of the stream channel both upstream and downstream, now that the knickpoint has migrated upstream and no longer occurs right at the crossing as seen in the early image.

View upstream showing the knickpoint in the stream channel that will continually erode upstream with future events.

High desert fluvial geomorphology...

on display in the canyons, washes and arroyos in mid- to upper-Castle Valley as a result of an intense thunderstorm two days ago. Erosion and sedimentation has occurred across a widespread area - both in and out of channels - but no structural damage was observed anywhere.

Flash flooding in Castle Valley...

occurred late this afternoon in response to an enormous storm cell that passed over the valley dropping about a half-inch of rain in less than an hour on hard-baked soils. Overland flow and sheet-flooding began immediately and ditches ran at full capacity along roadways for more than an hour. The National Weather Service did post both flash flood and severe thunderstorm warnings for the region and the last time an event this intense occurred was around 2010.

Peak runoff down the lane occurs as the storm cell moves eastward, with both roadside ditches running at full capacity. But a rainbow appeared and no personal property was damaged.

The low swale on the east side of my property took some runoff and sediment from small breaches in the berm along the roadside ditch.

UPDATE: The morning after in the mud bowl as the Town’s grader gets to work. There’s a lot of ditch maintenance that needs to happen beyond just clearing debris from the road surfaces.