The soil burn severity map included in that report shows that Malibu Creek State Park was one of the most severely burned areas in the Woolsey Fire. This was clearly evident as we ran/hiked along Bulldog Mtwy, Castro Peak Mtwy and Mesa Peak Mtwy. Here is a Google Earth image of the WERT Soil Burn Severity Map with a GPS track of our run added.
As mentioned in last week’s post, there had been some flooding and small debris flows along Crags Road near the M*A*S*H site and at the bottom of Bulldog Mtwy. This week we noted some rockfall along a stretch of Mesa Peak Mtwy that is prone to rockfall. Hazards existed before the fire and hazards exist after the fire.
Bulldog Mtwy and Castro Peak Mtwy had been recently graded and were in decent shape — at least as of December 29. Heavy rain may have changed that assessment.
As badly burned as the park is, there were some things to see on the plus side. The area’s vegetation was taking its first steps toward recovery, with grasses and other annuals, laurel sumac and wild cucumber sprouting. Most of the chaparral along the Mesa Peak Mtwy segment of the Backbone Trail between the picnic table at Puerco Mtwy and Tapia Park was left intact. Most of the Tapia Spur Trail was just outside the fire’s perimeter.
I’d done a long run the day before in Pt. Mugu State Park, so the plan for this morning was to do a short run and check out the Woolsey Fire impacts between Century Lake and the MAS*H site in Malibu Creek State Park.
In addition to checking the condition of the coast live oaks and other native trees, I was curious to see how the coast redwoods along the Forest Trail had fared. These trees were planted nearly a century ago and in recent years have struggled with the drought. Had they survived the fire?
It had been about a year since I had checked on the redwoods. The good news is that a few of them still appear to be viable. The bottom limbs on some of the trees were scorched, but I think they will be OK. Of the 16 or so redwoods, about five have died, about five are in poor shape, and five or six appear to be OK. There is one young naturally occurring tree that was severely scorched and may not survive. We’ll just have to see.
While there was some damage to the MAS*H site, the picnic tables, ambulance, and signpost made it through the fire. Some repairs will be necessary.
I was supposed to turn around at the MAS*H site, but you know how that goes. I wanted to see “just a little” of the Bulldog climb… and a little more… and a little more. I finally ran out of time about 2.5 miles up Bulldog Mtwy and headed back.
Even when you expect it, it is sobering to see areas of high soil burn severity. Thirty-six years of robust chaparral growth were just… gone. Also startling were the stream flows and debris flows that resulted from “only” about 1.5 – 2.0 inches of rainfall in early December. An atmospheric river event of the magnitude that caused the Malibu Creek flooding in February 2017 would be catastrophic.
A lot of work had been done on Bulldog Mtwy. It had been repaired and graded. Where there was still brush and trees along the road the branches had been trimmed!
The initial burn severity estimate is based on a Burned Area Reflectance Classification (BARC) derived from satellite data before and after the fire. In the map above the burn severity classes are high (red), moderate (orange) and low (yellow). Note that areas within the fire perimeter that are not included in these classes may still have burned. Also note the fire was still burning when this assessment was made.
GPS tracks of the Backbone Trail and some other trails in the region have been added. Trail and placename locations should be considered approximate.
The Google Earth image above shows a recent perimeter for the 2018 Woolsey Fire along with GPS tracks of the Backbone Trail and some other trails in the region. The Hill Fire perimeter and 2013 Springs Fire perimeter (purple area) are also shown. Trail and placename locations should be considered approximate. Here is a larger version of the map.
The perimeter was was downloaded from GEOMAC and timestamped November 18, 2018 at 5:59 a.m. If the timestamp of the perimeter of the displayed map doesn’t match, try refreshing/reloading this page. The perimeter has been refined and the acreage is a slightly less than previously specified.