Kiosk Watercourse Restoration, Redwood Regional Park

Updated Thursday, February 17 This is an ongoing project involving groups of kids, the regular Wayside restoration crew, and others.  My first introduction to the site was back in August, when I got to feel a bit like Livingston chopping his way through the jungle, but significant work has been going on here since at least last winter and likely shall be for some time.  And already, quite a change! (Thanks to ranger Pamela Beitz for providing all the photos for December, January, and February of last year.)

Here is how things looked on December 1, 2009.  The first shot is a general view of the area looking eastward across the park entrance road.  In the middle right of that photo there is a large coyote brush plant standing pretty much on its own, and it is from there that the second photo is taken, looking roughly northwards (photos are in HQ and work best if you click on them!):

Part of the issue here is erosion of upstream sediment into nearby Redwood Creek, which is bad for the native rainbow/steelhead trout that spawn there;  more on that in a bit.  As evident from these photos, however, the area is also thick with non-native poison hemlock and periwinkle.

By the next day some progress had already been made, with much of the hemlock removed and some of the existing natives flagged.  Expand slideshow to full-screen and click “show info” to see annotations for each slide:

These next photos, from February 11 of last year, are of a series of checkdams that had just recently been installed by a work party of kids under the guidance of the rangers.  Dams four and three are in the first photo (in that order, from the left), and dam one (the uppermost) is shown in the second photo.  The first photo also gives a good impression of the whole checkdam project area, with the broom-choked upper watercourse in the upper-left distance and the confluence with Redwood Creek just a few meters behind the photographer:

Which brings us to the reason for this project, namely, the major diversion of this watercourse from its natural channel some decades ago during construction of the park residence.  I am no expert on such things, but it appears to my untutored eye as though a bulldozer simply gouged out a giant rut and left it to eat through bare dirt, be colonized by thickets of broom and hemlock, and dump its sediment smack into the spawning gravels of Redwood Creek.  And so this restoration project appears to have two parts — slowing and settling the water and sediment by means of this series of small dams, and removing the monoculture of invasives to allow revegetation by native plants that hold streambanks and stabilize soil.

And already, by February 25 of last year, these dams appeared to be working quite well at slowing the water and catching some of the silt that otherwise would have flowed into the trout stream (which is just visible in the far upper left of the first photo):

And again, in another good rain storm in March:

Now, during all this time I was continuing with the broom pulling a bit further up the road, as we consolidated the progress we’d made through the impenetrable old-growth stands of broom on the steep hillside between the Wayside Picnic Area and the ranger station (more on this in a future post).  So much so that I hardly noticed what was going on with this watercourse restoration, other than always seeing Calvin down here pulling periwinkle.

But in August 2010, with a slim vacation-season crew, ranger Pamela had us combine forces at this location. Although much progress had been made with the periwinkle (Vinca sp.) since the project began, there was plenty left to pull, as well as a virgin forest of broom in the draw just upstream (behind the photographer in this view).  Photo is looking roughly south (downstream) along the entire checkdam area, with Calvin and Pamela pulling vinca in the distance.  Redwood Creek lies just beyond view, in the deep shady area where the trees begin:

While they continued work on the floodplain, I essayed clearing the broom thicket from the steep, machine-hewed watercourse.  The ability of French broom to seize and keep disturbed ground for decades was very evident here, as there was almost nothing else growing in the bulldozer’s swath (video is in HQ and works best in fullscreen):

And here are the simple before-and-after photos, sans action sequences:

Remembering that Redwood Creek is just a few tens of meters downstream of here, the lack of ground cover under the broom thicket does seem to have resulted in the disturbed soil eroding substantially over the years and, inevitably, ending up in the stream.  Fortunately those four little silt-catching check dams were well in place and ready for another winter!

These photos are from January 9, 2011:

And it is some winter we’re having.  We had around three summery weeks in January and early February, but as I write these words (midday on February 17) it is pouring, pouring, pouring all day, and at the time of these photos (January 9) it had been raining pretty much incessantly since November.  And the checkdams, by doing exactly as they are meant to do, had filled up (hit fullscreen symbol, then “show info”):

And so, I believe for the first time since they were constructed a year ago, it was time to clear out the accumulated sediment;  and, while at it, plant a few more rushes (Juncus patens) and other plants to hold the soil and eventually make the checkdams superfluous.  If memory serves, Pamela said that there were already some rushes here when the project began but that they really took off upon removal of the competing invasives.

And, “You can build a checkdam, but…”

Meanwhile, the ongoing effort to remove vinca, broom, and other invasives from the flat proceeded apace, while some of the French broom rootstocks started to come out of the steep upstream draw.  Although they had been lopped to just a foot or two off the ground back in August, broom is very resilient and generally sprouts right back unless the entire root is removed.

Part of the fun of this restoration work — and work it is, for sure, though very much of a kind with the good work that Wendell Berry writes about so eloquently — is that so much of this is so new, so untried, that experimenting is a natural and joyful part of it all.

For example, removal of all that French broom from this particular draw generates a pretty big pile of, well, French broom.  And pulling their rootstocks, though done to ensure revegetation and holding of the soil by locally-adapted native plants, does, in the short term, mean some loosening of the soil and greater potential for downslope movement in subsequent rains.  And so, why not try making checkdams out of the broom itself?  I don’t know if that is how Pamela came up with the idea, but its logic strikes me as inescapable.  And, as implemented, the resulting structures seem to me quite handsome, as well as potentially useful for slowing erosion until new plants take hold:

This pretty much catches us up with the present so I shall post subsequent developments under their own headings.  As I learn more about the history and development of this watercourse restoration project I shall post those things as well!

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