Reducing Incision and Gullying

Surface erosion, in the form of sheet and rill erosion, can eventually lead to the incision of large gullies. Sheet and rill erosion can best be diminished by maintaining vegetation or litter cover and minimizing exposed soil. Once gullies have begun to form, they can grow rapidly if not treated.

Small gullies can be controlled by filling in with soil and/or rocks, covering with mulch, and seeding with fast-growing grass seeds. Larger gullies may require check dams to slow water movement and thereby reduce its scouring effects. Check dams are barriers constructed in the gully or waterway of hay bales, piles of rock, brush, or logs, typically up to 0.5 m in height. Very large gullies may not respond to the construction of check dams and may require rediversion of water at the head of the gully or the construction of more permanent dams in the channel.

This document provides guidelines on restoring a deeply incised gully.

Above: A check dam decreases the erosive power of runoff.

Another approach for minimizing incision is to harden the stream channel. Increased runoff rates can be expected in areas with exposed soil. Predetermining the drainage channel and constructing it to be resistant to erosion is a preemptive measure to disrupt the progressive sheet-rill-gully erosion pattern. Channels can be stabilized using crushed rock, riprap (large, angular rocks), or geotextile erosion blankets. Channels can also be seeded or planted with native plants.