Water conditions 24 August 2018

We went up to San Jacinto Peak this morning and also on Tuesday 21st, the latter via Fuller Ridge and the upper Deer Springs Trail before a fire lookout shift at Black Mountain. On Wednesday 22nd August, I reviewed the springs and creeks around the Tahquitz area meadows when descending from a fire lookout shift at Tahquitz Peak.

As the San Jacinto Trail Report creeps slowly into the 21st Century, I thought I’d try an occasional short video blog. All the usual detail follows in the text below.

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Weather Rainfall from thunderstorms three days in a row last week, 15-17 August, included a spectacular storm cell over Idyllwild on the afternoon of 17th, when we recorded 1.50″ rain at home in under an hour! Despite similar rainfall on many parts of the mountain at the same time, impacts on water sources were remarkably short-lived.

At San Jacinto Peak at 0840 today, Friday 24th August, the air temperature was 51°F (10.5°C), with a pleasant windchill temperature of 43°F (6°C), a return to a more typical 39% relative humidity, and a firm 9 mph SW breeze gusting to 15 mph. It was even more autumnal on Tuesday 21st August, when at 0720 the air temperature was 49°F (9.5°C), with a cool windchill temperature of 40.4°F (4.7°C), 73% relative humidity, and a chilly SSW wind sustained at 16 mph and gusting just over 20 mph.

Despite the shift this week from monsoonal easterly airflow to more typical westerly maritime weather, hikers should always be prepared for rapidly changing conditions in the high country in summer. Thunderstorms with lightning can occur at or near the high peaks even when such storms are not forecast for lower elevations.

Trail overview Despite the rains of last week, flow rates at water sources have rapidly returned to being far below seasonal norms. Several well-known water sources are dry or are very close to drying up and should not be relied upon by hikers at this time. There is no snow anywhere on the mountain (all trails have been completely clear since early May). Details of the condition of high country trails following the 25-30 July 2018 Cranston Fire are described at an earlier posting linked here.


The Round Valley faucet is dry again, despite flowing for a few days briefly after rain on Thursday 16th. [Thanks to Florian Boyd for this update from today.]

The flow rates at the northern and southern springs at Wellman’s Cienega have dropped drastically since the rains, but both continue to flow gently. These springs are the sources for Willow Creek, which continues to flow where it crosses the Willow Creek Trail.

Wellmans North Cienega early this morning, 24 August 2018.

Tahquitz Valley has been completely dry for at least two months.

Tahquitz Creek continues to flow steadily at the northern (lower) end of Little Tahquitz Meadow.

Tahquitz Creek at the north end of Little Tahquitz Meadow, 22 August 2018.

Tahquitz Creek continues to trickle gently further upstream at its source (known locally as Grethe Spring) where it crosses the PCT at the northern end of the fire closure (approx. PCT Mile 177). Immediately after crossing the PCT, the creek dries up and disappears subsurface.

Tahquitz Creek crossing the PCT immediately below Grethe Spring, 22 August 2018.

Skunk Cabbage Creek is dry where the trail crosses Skunk Cabbage Meadow at the small wooden bridge.


The North Fork of the San Jacinto River continues to flow gently where it crosses the Deer Springs Trail, at about 3.7 gallons per minute (up from about 2.6 gpm prior to last weeks rains). However, the same river just downslope is now flowing very weakly where it crosses the Pacific Crest Trail on the Fuller Ridge Trail (approx. PCT Mile 186.2), at only 0.2 gallons per minute. The latter is extremely low flow for this critical PCT water source. These two crossings are the most important water sources for hikers on the western side of the mountain. Prior to recent rains the flow rate was the lowest in living memory, and it will rapidly return to that status without new precipitation.

North Fork of the San Jacinto River on Fuller Ridge Trail, 21 August 2018.

O’Sullivan Creek (PCT Mile 186.4) on Fuller Ridge Trail remains completely dry.

The spring in the creek in Little Round Valley has been completely dry since early June.

Shooting Star Spring – 0.28 trail miles below Little Round Valley – continues to flow significantly better than before the rain last week. For hikers it is possible to filter water from the source at the base of the obvious huge rock, but a better option is to descend to the North Fork crossing mentioned above.

The minor creek crossing (sometimes known as Rock Spring) on Deer Springs Trail midway between the North Fork of the San Jacinto River crossing and Shooting Star Spring, remained dry even during the rainfall, and has been dry across and below the trail since June.

The Deer Springs stream crossing at the PCT (approx. PCT mile 185.6) is dry, and the pools just upstream (and downstream) of the trail are also dry. The Deer Springs camp just downslope has been occupied by a crew from the California Conservation Corps since late May (although not since the fire evacuation on 25th July).

Switchback Spring – the small spring just below the eight switchbacks on Deer Springs Trail about 0.4 miles north of Strawberry Junction – continues to flow well. There is a tiny pool on the upslope side of the trail where water can be filtered if necessary.

Switchback Spring crossing the PCT, flowing well today, 17 August 2018.

The little spring in the rock crack at Strawberry Cienega (PCT mile 183) is back to flowing very weakly. For filtering, there is a tiny pool among the rocks (currently heavily obscured by plants). A permanently placed tent stake makes a clean accessible trickle out of the mud when flow rates are reasonable.

On Devil’s Slide Trail, Middle Spring has been completely dry since 26th July, with no significant flow even after last weeks rain.

On the Ernie Maxwell Trail, Chinquapin Creek just below Humber Park has been diverted by Fern Valley Water District to their storage tanks more-or-less continuously since 1st July, usually drying the creek where it crosses the trail. However good pools receive some fresh flow immediately upstream from the trail. This can be a very important water source for the many dogs walked on this trail.

One thought on “Water conditions 24 August 2018

  1. Hey, Jon. Thanks for the report, top notch as usual! I really am grateful you are out there keeping an eye on the water, trails, weather and peeps in general. Nice to see the vidblog, too! Yay!


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