It’s uncommon to have back-to-back Rain Years with 20+ inches of rain in Los Angeles. During Rain Year 2022-2023, Downtown Los Angeles (USC) recorded 28.4 inches of rain — about two times normal. This rain year Los Angeles has already had about 21 inches of rain, so another big year is in progress.
Curious to see how the trail conditions compare to last year, on February 17th and 25th I ran the Trippet Ranch Loop in Topanga State Park.
The big surprise was that the fire roads on the loop — Fire Road #30, Eagle Springs Fire Road, and a short section of Eagle Rock Fire Road — generally fared better than last year. Fire Road #30 had some damage along it’s shoulder, but I did not see the numerous mudslides along these roads like last year.
A little mud on the Musch Trail.
The news on the trails was divided. One of the more unusual events occurred where the Garapito Trail crosses the east fork of Garapito Creek. A mudslide from a gully on the northwest side of the creek crossed the creek, and left a pile of debris on the trail. The stream may have been dammed by mud and debris for a short time. Farther up the trail, about a half-mile from Eagle Rock Fire Road, a section of the trail collapsed in a slide.
Lately, I’ve been doing another option — adding an out and back from the Hub to Temescal Peak and Temescal Lookout and then continuing on the Trippet Ranch Loop from the Hub.
This extends the run to about 16 miles, plus Temescal Peak and Temescal Lookout are excellent viewpoints (video).
California fuchsia along Fire Road #30, near the Hub.
Downtown Los Angeles (USC) finished the 2022-2023 Water Year with 31.07 inches of rain, making it the seventh wettest on record in Los Angeles. The rainfall total includes about three inches of rain from former Hurricane Hilary as it moved through Southern California as a rare tropical storm and post-tropical cyclone.
Canyon sunflower blooming out of season along Fire Road #30.
The effects of all that rain can be seen on just about any trail in Southern California. It has resulted in a false Spring in many areas, with greening hills, out-of-season wildflowers, flowing creeks, and profuse growth throughout the area.
This morning, I returned to the Top of Reseda and Topanga State Park to do a variation of the Trippet Ranch Loop and continue exploring and enjoying the unusual conditions.
After running up to the Hub, this variation does an out and back to Temescal Peak and Temescal Lookout. After returning to the Hub, the route continues on Eagle Springs Fire Road down to Trippet Ranch. From Trippet Ranch, it works back to the Top of Reseda using the Musch and Garapito Trails and connecting sections of fire road. This interactive, 3D terrain map shows a GPS track of the trail run.
Dodder growing on laurel sumac on the Musch Trail.
Visiting Temescal Peak and Temescal Lookout increases the run’s mileage from 12.5 miles to 16. On a clear day, the runner is rewarded with far-reaching views of the coast, West L.A., Downtown, and the surrounding mountains.
While most of the roads and trails on this route are frequently used and in decent condition, the Garapito Trail has been overgrown all Summer. As of October 8, it was still overgrown. Some people I’ve encountered on the trail were OK with this, but others haven’t been so happy. If desired, the trail can be bypassed by continuing to the Hub on Eagle Rock Fire Road and retracing your route back to the Top of Reseda.
Update September 8, 2023. The new grass from T.S. Hilary’s rain is coming in nicely at Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch).
Tropical storms are a different kind of weather beast than usually seen in Southern California. The warmer air associated with such storms can carry much more water and produce unusually high amounts of precipitation.
The first hints of Hilary approaching Los Angeles.
The rain resulting from Tropical Storm Hilary shattered many daily and monthly records. Over decades of record keeping, most stations in the greater Los Angeles area had previously measured only a trace of rain on August 20 or 21, or at best, a few hundredths of an inch. Some stations had never recorded any rain on these days.
The highest rainfall amounts occurred where the precipitation was enhanced by mountainous terrain. The northeast-facing slopes of the eastern San Gabriel Mountains, near Wrightwood, were ideally positioned in Hilary’s circulation to enhance rainfall. The Big Pine RAWS recorded over 6 inches of rain for the storm, Lewis Ranch slightly over 7 inches, and Lytle Creek nearly 10 inches.
This crossing of Las Virgenes Creek was about the same as before Hilary.
Curious to see some of the local impacts of the storm, I ran at Ahmanson Ranch on August 22 and then a few days later at Malibu Creek State Park.
My West Hills weather station, about three miles from Ahmanson Ranch’s Victory Trailhead, recorded 3.86 inches of rain for the storm. After an initial technical hiccup, the Cheeseboro RAWS, overlooking Las Virgenes Canyon, recorded 3.52 inches of rain. This and other data suggest rainfall amounts in the Ahmanson area of at least 3.5 – 4.5 inches.
My Ahmanson run started at the Victory trailhead, went out East Las Virgenes Canyon, through part of Las Virgenes Canyon, and then up to Lasky Mesa. With that much rain, I was sure I would be wallowing in the mud and wading the creek crossings. But my shoes didn’t even get muddy!
Dry streambed of Las Virgenes Creek, north of the Las Virgenes Trailhead
As Hilary moved northward in California, the counterclockwise circulation of the storm increased the rainfall in the Santa Monica Mountains. Automated RAWS stations in Topanga, the Malibu Hills, and in Malibu Canyon recorded 4.0 to 4.5 inches of rain during the storm. CNRFC gridded precipitation data indicated higher amounts in some parts of the range.
Las Virgenes Creek in Malibu Creek State Park, about 5 miles downstream of Ahmanson Ranch.
On August 27, I ran the Bulldog Loop in Malibu Creek State Park. The run started at a small parking area at the junction of Malibu Canyon & Piuma Roads. As I was running up the Tapia Spur Trail, I wondered if State Parks had — as a precaution — removed the seasonal bridge across Malibu Creek on the Crags Road Trail. On August 19, the day before Hilary drenched the area, the bridge had been in place for the Bulldog Ultra. If it wasn’t removed, did Malibu Creek get high enough to damage it?
Once again, I need not have worried. The bridge was just fine, and the reeds in the water near the bridge suggested only a modest increase in streamflow.
It’s unusual for the slopes along Bulldog fire road to be this green in Summer!
It looked like Malibu Creek State Park received more rain than Ahmanson Ranch. There was slightly more erosion on the dirt roads and some small sluffs/slides, including one tree that slid onto Mesa Peak Mtwy fire road. A tree had also fallen near the beginning of the Forest Trail.
Back at Ahmanson on August 31, things were drying out, but it was beginning to look like Spring. Grass was sprouting all over Ahmanson Ranch. It will be interesting to see if the grass survives the inevitable heat and grows enough to turn the hills green. The little bit of rain and cooler weather over Labor Day weekend will help. Some out-of-season wildflowers could also result from a false Spring.
Yesterday, I did a run in Topanga State Park, and the story was much the same. There was some minor erosion on the fire roads, but none of the larger sluffs and slides seen during the rainy season. There was no new damage to the Musch or Garapito Trails. It did look like the flow had increased on Garapito Creek with Hilary’s rain, and there was a still little water in the mainstem of the creek.
