Stream Remediation 1

From 11:00-11:40 this morning (2010 July 6) I did my first session of stream remediation in the 5th Road valley that starts by Steve’s house. It’s the closest primary valley to my house. In 40 minutes I did 75 feet, which is about 2 feet (1.875 feet) per minute by one person. I measured my pace at about 3 feet and paced the rest of the valley — it measures about 450 feet to its junction with the main valley. (75 feet done + 450 feet below + 75 feet above = 600 feet) X (1/2 minute per foot per person) / (60 minutes per hour) = 5 hours, estimated work time for one person to do the whole primary valley (and I already did 40 minutes of that). There are eleven residents that might average 1.5 feet per minute, so together we can do 16.5 feet per minute = 990 feet per hour. We could do that valley in about 40 minutes.

Me building a one-rock-high dam in a stream bed.

Me building a one-rock-high dam in a stream bed.

Dry stream bed with rock dam and sticks I tossed in.

Dry stream bed with rock dam and sticks I tossed in. (5 ft. tape measure)

From the junction of the primary valley and the main valley, it’s about 450 feet upstream to the head of the main valley, which seems to be formed by the junction of two primary valleys (though I didn’t walk up them to find out if they really are primary valleys).

What I did:
I walked along the banks, about 30 feet on both side from the center. In my first pass I tossed rocks into the valley. Then I made non-buried one-rock check dams about every 15 feet. Then I made a second pass along the banks and tossed in sticks and logs ranging in diameter from 1/3 inch to 6 inches (that was the biggest present on these banks). I tossed the sticks and logs in at many angles, not just straight across the valley. There are leaf dams accumulated around sticks that are not perpendicular to the valley, so I figured the angle isn’t too important.

I took photos, with a tape measure in each photo.

I measured Steve’s house to get the square footage of his roof: 40 x 40 = 1600 sq ft footprint. With that and the appropriate formula, I could calculate the volume of water that the roof sheds per inch of rainfall. The primary valley starts about 20 feet from the house, and he has the gutter pipes aimed right at the middle of the valley, which is the most erosive position.

Steve's house

Steve's house, 40 ft by 40 ft roof = 1600 sq ft footprint.

Gutter draining into pipe.

Gutter draining into pipe.

Gutter pipe draining at head of primary valley.

Gutter pipe draining at head of primary valley. (tape measure 12 inches)

Head of the primary valley.

Head of the primary valley.

What I might do differently:

  • Halfway bury the first line of rocks in a check dam, as instructed by Kirk Gadzia in the Holistic Management session of the 2009 Carbon Farming Course. Intention: these would be more flood-resistant than loosely piled rocks.
  • Cut bamboo stakes 2 feet long, with a flat end and an angled end, and pound them into the valley in lines perpendicular to the valley every 15 feet. Intention: these would be more flood-resistant than loosely piled sticks, so could anchor debris and make dams. These might be more useful in the main valleys where erosion is much worse. These would be easiest to pound in when the ground is wet (it last rained about a week ago, so the ground is dry right now).
  • Carry paper and pen to note the location of each photo and the length of the tape measure in each photo.

Why I did this:
To stop erosion. To plant water, to plant soil. To decrease downstream water turbidity. To exercise outside in the morning, which I enjoy and makes the rest of my day more pleasant.

Eroded bank in the main valley -- about a 7-foot vertical erosion face. (tape measure 7 feet)

Erosion at the head of the main valley -- a 44-inch deep bowl braced by tree roots. (tape measure 44 inches = 3 ft 8 in.)

Erosion at the head of the main valley -- a 44-inch deep bowl braced by tree roots. (tape measure 44 inches = 3 ft 8 in.)

How we might do this Farm-wide:
Organize by neighborhood. Have one or two Farm-wide leaders, and a leader in each neighborhood. Each neighborhood signs up for a time (either do one week per neighborhood, or one day of the week per neighborhood). The Farm-wide leader is responsible for: investigating, developing, and sharing the technique and related knowledge; and documenting the work with photos and measurements. One knowledge spreading method is to have field days in each neighborhood: the residents of those valleys give a tour and answer questions from folks from other valleys (and the Farm-wide leader). We could do 90 minute work sessions, with 15 minutes prep and 15 minutes wrap up, for a total of 2 hours of attention. Do it in the morning or evening — probably fewer biting insects in the morning.

Bring in someone to speak about stream ecology, stream classification, geology, hydrology, and stream remediation. Perhaps there are State employees who offer such presentations without charge. Perhaps Wade would know, or Cynthia Rohrbach. Have a community dinner: screen “The Man Who Planted Trees” or “The Upward Spiral“, then do dinner (do not try to work through dinner), then a walk-around-to-different-info-and-creation-stations time (an after-dinner activity that’s not sitting still), then a presentation by the main speaker, then a conversation time.

Evidence that something similar works without immediate human action:

Branch that functions as dam for leaf pile.

One branch can effectively brace a leaf dam that slows water, and thus helps the soil stay in place instead of washing away and causing turbidity downstream.

4-inch rock bracing the branch in the photo above.

The branch (in photo above) that braces leaves is in turn braced by a small rock that's partially buried.

Following the example of how the forest heals itself, we can effectively speed that healing. Perhaps this is a step towards what my friend Connor Stedman means when he says humans might live as keystone species.

For more inspiration, see these two films, available online:

Advertisements
This entry was posted in Stream Remediation. Bookmark the permalink.

2 Responses to Stream Remediation 1

  1. Paul Krafel says:

    Hi, kindred soul,
    May your work nourish you and the earth alike.
    Isn’t it fun.
    Feel free to contact me if you wish to discuss more. The technique I am really aware of right now is finding places high in a drainage where a contouring channel can lead water from the drainage onto the adjoining ridge. I, like you, am really trying to photograph and document the effects of such work.
    Paul (The Upward Spiral)

  2. Pingback: 180° South and Wild Places | Amarillo Tableland – Local Gardening and Food

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s