Sheetflow Erosion Control Erosion Control for the CESCL

November 26, 2020

Why Perimeter Controls?

Filed under: Power Point — Tags: , , , — Sheetflow @ 1:43 am
Presentation: David Jenkins

Why are perimeter controls necessary? Here are few reasons: keep clean water out of your project and keep dirty water and sediment in your project.

November 25, 2020

Non-Standard Perimeter Controls

Filed under: Power Point — Tags: , , , — Sheetflow @ 1:33 pm
Presentation: David Jenkins

Last month, I did a presentation on non- standard perimeter controls. These are controls other than silt fence, which is the standard perimeter control on construction projects.

While silt fence is the appropriate perimeter control in many situations, (the bottom of a slope), it is inappropriate is so many other situations.

Over the next few weeks, I will post the presentation slides and talk about some of the non-standard controls.

April 7, 2020

Silt Fence Water Bars Fail

Photo: David Jenkins

Whenever I see something like this, it makes me think that the site owner/contractor either didn’t know what they were doing or bit off more project than they could chew, or both. These guys cleared, grubbed and graded something over 80 acres starting in late summer, failed to phase the work, failed to use soil cover practices, failed to listen to the experts and got nailed by the fall rains.

Erosion control is really about water control: reducing volume, preventing it from becoming turbid, and controlling where it goes. By the time the rains hit this project, there was too much water, it was too dirty, and there were too few options for controlling where it went.

In addition, they refused to set up a chitosan-enhanced sand filtration system to treat and discharge water; this left them no options and too much turbid water that had nowhere to go. As a result, they hammered a wetland, were fined heavily, and were shut down for months.

Silt fences are not meant to control water, convey water, filter water; they are designed to control eroded sediment. Ditches, berms (rock, gravel, triangular silt dikes, etc.) would have been better choices at this location. Not opening up so much area so late in the season would have been the best option. Their means and methods did not save them time or money.

October 31, 2019

Is This Silt Fence Necessary?

photo: David Jenkins

Is this silt fence necessary? Overlooking the fact that this silt fence installation needs some maintenance, I wonder if it was ever really needed in this location? The slope grades to the fence are minimal and not very long, and the roadside ditch line is graded so that water will drain away from the road.

This type of silt fence installation is appropriate at the base of long, steep slopes, or if there is risk of sediment travelling off site. Also, all of the materials used will likely be land filled and not reused, including the wire backing and the “T” posts.

If this were my site, I would have installed orange safety fence with steel “T” posts, maybe with a compost berm along the base, on the project side. The safety fence can be easily removed and reused later, and the compost could be raked into the ditch line and hydroseeded.

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