Preparing for Fall and Winter Rains

By Dave Jenkins posted Aug 27, 2022 09:28 AM


#Preparing for Fall and Winter Rains

Tags: bark, #CESCL, clear and grub, construction erosion, cover, divert, erosion and sediment control, erosion blanket, erosion control, #hydroseed, pipe slope drain, plastic sheet, rock, sand bag, #constructionerosioncontrol, seeding, silt fence, straw mulch, topsoil, trackwalk,#construction

Something I wrote up for Washington State Department of Transportation in 1996.  I think it still applies.  What do you think?

Fall is approaching, now is the time to get construction projects ready. Here are some things to consider:

  1. Cover bare soil. Final grades can be covered with hydroseed, erosion blankets, topsoil, bark or whatever final cover is planned for the project.
  2. Get your hydroseed contractor lined up now and avoid the October rush.
  3. Don’t open up more than a few acresat a time after September 1st.
  4. 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.
  5. Track your slopes with a Cat: up and down slope, not across slope. This alone can reduce erosion up to 50%.
  6. Use flex pipe drains at bridge ends if your permanent drainage system and curbs are not in place. Collect the water from the bridge  and divert it to the pipe. Make sure the pipe is long enough to reach the bottom of the slope.
  7. Use a water truck and water seeded areas weekly to get quicker growth. The better the growth going into fall and winter the better.
  8. 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.
  9. 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.
  10. Locate all existing water flows in and around your project and find out where they drain to.  Convey them away from your project.
  11. 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?
  12. Get materials on site now. 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, to cover all areas that are bare.
  13. Set up emergency procedures. 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.
  14. Make sure that erosion control material installers know proper installation methods.
  15. 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.
  16. 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.
  17. 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.
  18. 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 to keep in their truck. 
  19. Make sure that all check dams are installed so that the top center point is lower than the bottom end points. This prevents endcutting. You may have to add more material to the dam to increase the width, especially on wide ditches with shallow grade side slopes.
  20. Anything else you can think of.
Stormwater pond plugged and being used to contain construction runoff to be chemically treated.  During a heavy rain event, the treatment system could not treat fast enough and the pond began to overflow to a creek.

Photo: Dave Jenkins, CPESC

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