Draining the Poison Oak Swamp

01 May 2011

From a junction with Wilder Ridge Loop fire road, a narrow single-track trail heads generally west following the rim of Old Dairy Gulch. Just over the hill from the junction the trail dips low to cross one of the many channels that drain water into the gulch. The terrain above the trail forms a funnel that drains several acres of open hillside. Below the trail it levels out allowing water to linger during the rainy season to nourish a lush thicket of poison oak. Inevitably, the slow moving water softens the trail making it susceptible to damage from boot soles and tire treads.

The red that you see in these poison oak leaves is fresh spring growth.
The red that you see in these poison oak leaves
is fresh spring growth.
This seems to be characteristic of locations
that get a lot of direct sunlight.


Bountiful crop of poison oak berries
This bountiful crop of poison oak berries
may be the product of plentiful rainfall.


Yes, all that sunlit green in the background is poison oak.
Yes, all that sunlit green in the background
is poison oak.


Tamp! Tamp! Tamp! Can you find the culvert exit with its natural looking camouflage?
Tamp! Tamp! Tamp! Can you find the culvert exit
with its natural looking camouflage?


That’s the high side catch basin on the right and a drainage ditch on the left.
That’s the high side catch basin on the right
and a drainage ditch on the left.
A little patch of grass adorns the culvert entrance.


Off-camber descent onto our new, elevated trail tread.
Off-camber descent onto our new,
elevated trail tread.


Last month as we worked our way along this section of trail cleaning and improving drains as we went, we pondered whether it wasn’t about time that we did something a little more ambitious to protect trail at this swampy crossing. In the end, we acquiesced to the better part of inspiration and postponed that project thinking that we should be a little better prepared before taking it on. With that in mind, we closed out the April workday by retrieving one of the eight-foot pieces of four-inch PVC pipe that has been stashed out behind some coyote brush up near the big Black Earth Swamp soaking up UV rays for the past two or three years. After surviving our field test for structural integrity (Too bad we didn’t get a photo of our technician jumping up and down on it.), we carried it back to the Poison Oak Swamp and attempted to store it in a way that would not present an unsightly distraction to trail users.

Even though we didn’t make any great effort to publicize this project, word must have leaked out. Just look at all the folks who came out to help us bury a pipe!

Rich Seiter
Drew Perkins
Ange Chao
David Kelley
Ben Schoettgen
Kristin Cockerill
Tucker Stanwood
Roger Kern
Zach Dammann
Leslie Cuevas
Fred Aron
David Aron
Nora Aron
Verity Aron
Chase Sturaf
Harvey Hartman
Greg Lydon
Chuck Wisse

It took our driver, Brian Smith, two trips with the State Parks truck to transport everybody to the work site. To augment the larger than average crew, we arranged to have beautiful weather and perfect soil conditions. We would have to move a lot of dirt to get the job done. There was just enough moisture in the soil so that it was easy to dig without being slippery, sloppy, or excessively sticky, but with enough adhesion to tamp well when we needed to pack it back down over the pipe.

Given the limited drop on the low side of the trail, we had to be careful not to go deep with the initial trench for the pipe. This, in turn, would require that we build up a raised trail bed above the grade of the existing trail. The dirt for this raised bed would come from the catch basin that we would dig out on the high side of the trail after setting aside the top layer of vegetation, turf with some sprigs of poison oak, for ‘landscaping’ the finished product. Native rock was used to camouflage the pipe ends. And, if I may say so, the net result is an attractive bit of landsculpting.

The first major test of our work would come in two weeks when the XTERRA Pacific Championship race, a triathlon event that would send upwards of 180 cylists racing over our new protective trail feature. Some of the bicyclists among todays volunteers pointed out that the steep, downhill approach to our little causeway was more than a little off camber with a narrow, eroded ditch on the low side. Racers would rather ride the ditch than risk losing traction on the trail tread and sliding into it unintentionally. But a fix for that would have to wait for another day.

Still, we made a difference today that anyone can plainly see. Many of us will be looking for the effect of that difference during the next rainy season.



15 happy faces in this group shot at the end of the day.
There are 18 names on the crew roster and only 15 happy faces in this group shot at the end of the day. We keep a close count of tools when we check them out from the storage closet, but it appears that we lost a few volunteers out on the trail. Actually, two people had to leave early due to a prior commitment, and we thank them for multi-tasking us into their busy weekend. And one person arrived and departed the work site by bicycle.