Building an Armored Swale

Today Jessica M. and I (both volunteer stewards) tackled a Montini trail project that I had long planned. There was a place on the Rattlesnake Cutoff Trail where water, during heavy storms, would flow across the trail. Since the initial construction of the trail didn’t take this into account, the water would pool on the trail, leading to a long trail segment that would essentially turn into a tiny lake (see photo).

The Montini Preserve was heavily mined in the early 1900s (this property and adjoining Schocken Hill, now the Sonoma Overlook Trail, essentially paved the streets of San Francisco at the time), and there is a quarry “divot” in the hill above that collects rainwater and funnels it out to the trail. Being essentially bedrock, the water has nowhere to go but out and down. 

The finished armored swale.

What the trail needed is what’s called an “armored swale,” which is essentially a channel cut into the trail that is protected by a floor of rocks to prevent erosion. I had been waiting for rain to soften the soil, as we would first need to excavate the existing rocks and in summer the ground is like concrete. It rained yesterday, so the soil was going to be about as soft as it was going to get. Also, since I knew that an “atmospheric river” was set to dump several inches of rain in a matter of a few days, now was the time to act.

So Jessica and I went out today and built it. We first needed to excavate a channel across the trail, then place stones to protect from erosion, and fill in gravel and soil around the stones. Do your worst, atmospheric river, we’re ready for you!

Prepping the Trails for Rain

Since rain was predicted for today (and it came!) I headed out earlier in the week with a mattock to clear trail drainage channels, which had become clogged with rocks, leaves and miscellaneous debris since spring. Water must be guided off our trails immediately or else it will erode the trail and harm it, especially over time. Plus we don’t want the soil that gets eroded to end up in our waterways.

I also cut new ones where I thought they may be needed. Some of this work is obvious, but I know that additional work will be needed once we actually have flowing water on the trails and can see the trouble spots, where water is pooling or running down the trail.

This is just one task that the volunteer stewards group does throughout the year to keep our trails safe and well-maintained.

 

Snake Season

We are thoroughly in snake season now, with rattlesnake sightings up dramatically this year. That news made me dismayed that I had yet to see a single one, despite being on the trail (and off) every day. All that changed today, when I saw two in one place (see photo). One appeared to be my old friend “Big Jo(e)”, which has a characteristic dark coloring and at least ten rattles. The other snake was new to me, with a distinct greenish hue and also a large number of rattles. It is the one coiled in the picture. I guess now I have to come up with another name!

The location where they were sighted was off the trail to the left when going up Holstein Hill trail, just prior to the wide wheelchair turnaround spot, also called “Coyote Point.” Since one snake subsequently slid into a crevice in the rock wall, it’s possible that there is a den there, so be extra careful in that area.

Meanwhile, keep your eyes open anywhere on these properties and stay safe out there!

 

Completely Determined. Thoroughly Implacable. Absolutely Relentless.

Before: Note the white fluffy seeds.

Doing invasive species removal work has its ups and downs. Not long ago, I was down. But the mood tends to pass, and I picked myself up and got back to work.

And when I did, it was with a renewed sense of purpose: I refuse to be defeated.

I even know exactly how that works: you must be absolutely relentless, completely determined, and thoroughly implacable.

After.

This year I even upped my game. In previous years, by now I had stopped pulling Italian thistle, as it was going to seed. I thought that pulling it would simply spread the seeds. But this year, when I kept pulling it, I realized a few things:

  • It’s possible to pull it without spreading seeds. This can be done a couple of ways: one is to push the head of the thistle into the bag before you pull it. Another is to grab the thistle at the head where the seeds are coming away, pull it out, and put it all in the bag.
  • A large number of plants went dry without yet releasing its seed. These are easy targets.
  • I’ve even begun picking up the seeds themselves. Not in all cases, but certainly at times (see the before and after photos).

I’ve learned some other things: 

  • I have more determination than I ever knew I had.
  • I can make a real difference.
  • Being absolutely relentless works — it just takes time. Thankfully, that I have.

I see you, thistle, and I’m coming for you.