holyoutlaw

As I study North Beach Park, I learn more and more how dynamic it is, and how much of an effect water flow has on it.

We’ve noticed a rill forming on a steep hillside. I think it might have started when some mountain beaver tunnels collapsed, but my theories usually only have a passing relationship to reality.

Here is a picture of the rill. The area of concern starts in the center of the picture and slants down to the left.

This was taken Saturday (9th), after Drexie and I had installed a few nootka rose live stakes. Nootka rose is supposed to live stake pretty well, and this area is too dry overall for salmonberry.

This is Drexie, in the process of putting the nootka rose into the ground.

The area we were working in was very steep and soft, in that the ground moved under our feet.

On Monday (11th) Tad and I went back to the rill and did some more work. We added a fence or dike made of branches from a fallen alder (there are enough of those around).

We staked the dike on both sides, then wedged some rolled-up burlap sacks at the base.

The burlap provides a finer barricade to the dirt than just the stakes and branches would, yet will still allow water to flow through if necessary. The branches were pushed back over the burlap. Just for belts and braces’ sake, we added some regular stakes on the uphill side of the entire structure.

Last but not least, we added some wood chips to the whole thing.

We could have added another couple buckets of wood chips, but it was time to go.

Still to come: More wood chips and a tree below the structure to buttress the whole thing.

Mirrored from Nature Intrudes. Please comment over there.

This spring, the Parks Department gave North Beach Park 1/4 acre of invasive plant clearance on steep slopes, an area volunteers are not allowed to work. I’ve always assumed it was a liability issue, which I think now is only partly the case. I now see it as a skill set issue as well.

I forgot about it until I was asked to review the contract a couple weeks ago. In the meantime, I had allowed a group of volunteers… um… to work on some steep slopes in the very area the crew was being contracted to work. Which caused some confusion we’re still resolving.

In the last week, the crew has come in and done some erosion control and some new invasion removal.

Here’s a side view of some of the erosion control on the Headwaters Bowl slope.

The jute netting is rolled down the hill. Successive stretches of netting are stitched together. At the top of the slope, a narrow trench is dug, and the netting staked into it with 2×2 stakes. This is covered up when the trench is reburied.

There were some restoration plantings at the top of the slope that they worked around. They also preserved some restoration plantings at the bottom of the slope. (After taking this picture, we mulched around the plants.)

Here’s a side view of the HWB slope erosion control. It’s steeper than it looks from this angle. The wood and branches are laid on the jute to weight it down. Here is a view of the slope before removal, with some workers at the bottom to give a sense of scale.

The crew also did some work in another area of the park, even steeper, the North Slope.

You can see the stitching a little better in this picture. The coir log is laid across horizontally to absorb any street run off from 90th St/25th Ave.