Sheetflow Erosion Control Erosion Control for the CESCL

December 18, 2020

Prepare for Fall and Winter Rains by Preventing Erosion

This is a blast from the past. I think I wrote this in 1996 with I was the first State-wide Erosion Control Coordinator at the Washington State Dept. of Transportation.

Preventing erosion is the best preparation.  Here are some things to consider when you prepare for fall and winter rains:

Cover bare soil. Final grades can be covered with hydroseed, erosion blankets, topsoil, bark or whatever final cover is planned for the project.

Get your hydroseed contractor lined up now and avoid the October rush.

Don’t open up more than a few acres after September 1st.

Grades that aren’t being actively worked can be covered with straw at a rate of 3000 pounds per acre. This is a very cheap and effective way to protect bare soil from raindrop impacts and erosion. Hand seed before spreading the straw. Spray it with water to help hold it in place.

Track your slopes with a Cat: up and down slope, not across slope. The first helps prevent erosion, the second speeds it up.

Use flex pipe drains at bridge ends if your permanent drainage system and curbs are not in place. Collect the water from the bridge using sand bags and divert it to the pipe. Make sure the pipe is long enough to reach the bottom of the slope.

Another good way to prepare for fall and winter rains is to use a water truck and water seeded areas weekly to get quicker growth. The better the growth going into winter the better.

If you have to open up a large area, only clear and grub small areas. You can clear larger areas if you don’t grub. Roots and slash help protect the bare soil.

Walk the site looking only at erosion controls, thinking ahead of areas that could have a problem. Identify them and start making additions and corrections.

Locate all existing water flows in and around your project and find out where they drain to.

Think about maintenance and regular inspection of erosion controls. When are silt fences going to be inspected and who does it? Who removes mud from check dams? Who covers slopes with straw or other mulch?

Get materials on site now. Again beat the rush for materials in October and November when everyone is in a panic to get plastic and straw. Stockpile enough straw, plastic, silt fence, flex pipe, sand bags, seed, rock, now to cover all areas that are bare.

Set up emergency procedures now. Who should be called in emergencies? Do you have a Certified Erosion and Sediment Control Lead (CESCL)? Brief your personnel on what to do if they see muddy water and who to go to.
Make sure that erosion control material installers know proper installation methods.

Make sure all your silt fence is installed on contour with the ends flared up slope a few feet. If it is not on contour, identify the lowest points of the fence as these will be the failure spots. Install a double row of silt fence at these low spots before you have a failure. Double up your silt fence in areas where eroding slopes could flow into wetlands or streams.

Do you have bare spots where previous seeding hasn’t grown? Cover it with seed and straw if the area is small, remobilize the hydroseeder for larger areas.

Make sure all catch basins within the project boundary are protected with inserts, fence surrounds, or other methods to keep mud out. Locate any catchbasins outside project boundaries that may receive water from your site and protect them.

Make sure that you have a copy of the  Temporary Erosion and Sediment Control plan (TESC) and any grading or environmental permits on site in the job shack. Know what they say. Give each inspector a copy of the TESC to keep in their truck. These are working copies that can be adapted to site conditions.

Modify your permanent stormwater ponds into temporary sediment ponds by installing a standpipe and blocking the outlet with sand bags. Cut a few small holes in the standpipe to allow for slow release of water. You can also use perforated pipe as the standpipe and hold it in place with “T” posts, wire, and gravel piled up around it.

Use geotextile fabric as a temporary ditch lining to protect bare soil from erosion. Hold the fabric in place with rock check dams, wooden stakes, or sand bags.

Make sure that all check dams are installed so that the top center point is lower than the bottom end points. This prevents end-cutting. You may have to add more material to the dam to increase the width, especially on wide ditches with shallow grade side slopes.

Now you know how to prepare for fall and winter rains: Prevent Erosion

November 17, 2020

Silt Fence Here?

Photo: David Jenkins

Would I put silt fence here? I would not. The work involves installing an 8 inch ductile water line to a property up the hill. The connection to service is at the left orange cone. The other orange cones are located on the backfilled excavation. I would have specified a gravel berm, asphalt berm, burlap fence, orange construction fence, or a combination.

November 16, 2020

A Final Inspection

I am conducting a final inspection of erosion controls at a former staging area. Some of the best management practices shown are: silt fence, straw wattles, and hydroseed.

Video: David Jenkins-Sheetflow Erosion Control

November 4, 2020

Silt Fence Inspection

Filed under: Photo — Tags: , , , , , , — Sheetflow @ 6:53 am
Photo: David Jenkins-Sheetflow Erosion Control

This silt fence looks pretty ugly and inspection shows it certainly needs maintenance; but does it? The silt fence made sense before we excavated several feet, now it doesn’t. There is a turbidity curtain in the river to the right and the contractor is careful to pull material back from the riverbank. I am going to let this go.

October 21, 2020

Perimeter Controls Presentation

I am giving a presentation on Perimeter Controls: Non-standard Practices for Managing Water and Sediment today at noon. Go to Erosion and Sediment Control Association- British Columbia for information and to sign up. It’s only 10 bucks.

Description-Silt fence is not the only perimeter control BMP option. It is not the best option in many situations. In this presentation, I will discuss when silt fence makes sense, when it doesn’t, what other options are available.

October 19, 2020

Windy, Dusty, No Water

Video: David Jenkins-Sheetflow Erosion Control

It’s windy, dusty and there is no water. Wait! Hey man, there is a hydrant right there. Use it, spray the dirt, keep the dust down!

October 16, 2020

Boulder Fence Silt Fence

Photo: David Jenkins-Sheetflow Erosion Control

I like boulder fence but I hate silt fence. I hate that it is plastic and not recyclable and that it ends up in the land fill. However, it is very strong and in this instance it is the right BMP.

September 29, 2020

Sod Berm Perimeter BMP

Photo: David Jenkins

This is not one of my projects but we have used this method on occasion. Why install silt fence when you can create a sod berm perimeter BMP?

In this case, the area is small and it is surrounded by vegetation so the risk of erosion and turbid runoff is low. In addition, the sod is full roots and seeds so it will regrow in place, providing additional erosion prevention.

September 25, 2020

Gravel Berm

Photo: David Jenkins

When we rebuilt this road, we had the contractor blade the gravel base course into a berm along the edge. This created a berm to project the bare area on the left from erosion caused by runoff from the roadway.

The gravel berm was bladed smooth just before installing a curb along the edge of the road. The bare soil was hydroseeded with bonded fiber matrix.

By using the gravel in this way, we avoided installing silt fence, preventing the soil disturbance that causes and keeping a bunch of plastic out of the landfill at the end of the project.

August 18, 2020

Silt Fence, Covered Stockpile

I saw this driving by a new apartment building project.  Everything is so tidy.   They attached the silt fence to the cyclone fence and  secured the black plastic from damaging wind.
Photo: David Jenkins

I saw this driving by a new apartment building project. Everything is so tidy. They attached the silt fence to the cyclone fence and secured the black plastic stockpile cover from damaging wind.

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