Sheetflow Erosion Control Erosion Control for the CESCL

December 10, 2020

Infiltration Berm

I call these infiltration berms. They aren’t berms like the others in this presentation but they function the same way-they contain water, divert water, or both.

The first two photos show created berms and the last is a utility trench that has not been paved yet. The first two were installed to contain the dirty runoff from muddy shoreline rip rap that we had to remove to install piling.

The berm surrounds about two acres of paved surface. The asphalt was removed to expose the subgrade to allow runoff to infiltrate. These can be designed but we didn’t have time.

To do this correctly, you should figure out how much runoff you will have, how much storage volume to create (this determines how long and how wide the trench is) and the actual infiltration rate of the subgrade.

The last photo shows how you can use your site to your advantage.

Presentation: David Jenkins-Sheetflow Erosion Control
Presentation: David Jenkins-Sheetflow Erosion Control
Presentation: David Jenkins-Sheetflow Erosion Control

March 8, 2019

Curb Inlet Protection

According to the Minnesota Stormwater Manual:

“Curb Inlet protection devices intercept and/or filter sediment before it can be transported from a site into the storm drain system and discharged into a lake, river, stream, wetland, or other waterbody.

These devices also keep sediment from filling or clogging storm drain pipes, ditches, and downgradient sediment traps or ponds.

Inlet protection may also include placement of a barrier to create a bypass of an inlet transferring flow downstream to a sediment trap, basin, or other inlet discharging to a non-critical area.”

Nothing wrong with sediment control BMPs, as they are necessary tools in an effective erosion and sediment control system.  However, these do not “filter” sediment. 

When properly installed, these allow for ponding of water which allows larger sediment to settle out, keeping it out of the storm system.  This is a good thing, but doesn’t necessarily prevent water quality non-compliance.   

I do like this statement in the manual : “Caution: To the extent feasible, erosion prevention practices such as stabilization are preferred to sediment control practices.”

In my world, where we have to meet a turbidity effluent limit of 25 NTUs, stabilization and stormwater management are the primary methods used to meet strict turbidity limits.  

Photo: David Jenkins

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