Diversion

Earthen embankment similar to a terrace that directs runoff  water from a specific area.

How it works

A diversion is much like a terrace, but its purpose is to direct or divert runoff water from an area. A diversion is often built at the base of a slope to divert runoff away from bottom lands. A diversion may also be used to divert runoff flows away from a feedlot, or to collect and direct water to a pond.

How it helps

Reduces soil erosion on lowlands by catching runoff water and preventing it from reaching farmland below.
Vegetation in the diversion channel filters runoff water, improving water quality.
Vegetation provides cover for small birds and animals.
Allows better crop growth on bottom land soils.

Planning ahead

Are there proper soil conservation measures installed to prevent the diversion from filling with sediment?
Is the outlet planned in a location which will not cause erosion?
Is the diversion and outlet large enough to handle the runoff amount for that location?

Tech notes

Diversions cannot substitute for terraces used for erosion control.
Diversions must be built to carry at least the peak amount of runoff generated by a 10-year, 24-hour storm. *
Minimum top width for a diversion ridge is four feet. *
Each diversion must have an outlet. A grassed waterway, grade stabilization structure, or underground outlet is acceptable.
Establish vegetative outlets before a diversion is constructed.
Diversions should not be built in high sediment producing areas unless other conservation measures are installed too.

Maintenance

Keep outlet clear of debris.
Keep burrowing animals out of the diversion.
Maintain vegetative cover on the diversion ridge.
Install filter strips above the diversion channel to trap sediment and protect the diversion, if needed.
Fertilize as needed.

* Check local recommendations.