Using riprap, which is rock that is angular and irregularly-shaped to line channels can prevent erosion by runoff. The same is true for hard-armour type of product.
Implementation
After you build the channel first, excavate the cross-section to the grades found on the plans. You’ll need to over-cut the channel so there is room for the grass and filler. Now, place a layer of gravel filler or geotextile for the underlay. Once completed, you can now place the well-graded riprap.
Place the riprap or suitable hard-armour product in the channel, so that it creates a uniform, well-graded and dense mass with few open spaces. You may need to hand-place the riprap to avoid damaging the underlay and properly distribute the material. The outlet should be free of over-fall, which scours the channel. The riprap bottom with grass covering should have smooth contact to avoid open spaces and potential erosion.
Inspection & Maintenance
Inspections should be conducted on a regular basis and especially after an intense precipitation even or snowmelt. Any accumulation of sediment, piping, scouring, or instability in the bank will need to be addressed. Focusing on the outlets and points where the concentrated flow will enter the channel needs to be accomplished.
Proper documentation of the condition of the channel to see areas of buildup or erosion, so that they can be corrected. Plus, removing all accumulated sediment along with repairing damage quickly will keep the channel open.
Tag: Erosion, construction, inspection, Sediment Control, runoff, riprap, channels, grass, channel, damage, filler, gravel, underlay
