There are a few activities which involve the placement of fill in a waterway that are not subject to the Section 404 regulatory progaram. However, the fill must not change the use of the water and the flow must not be impaired. These exempted activities are breifly described below, and located in the regulations at 33 CFR 323.4.
1. Normal farming, silviculture and ranching activities such as plowing, seeding, cultivating, minor drainage and harvesting.
2. Maintenance or emergency repair of a currently serviceable structure such as dams, riprap, abutments, and levees. The orginal design may not be changed.
3. Maintenance or construction of stock ponds or irrigation ditches. Maintenance (not construction) of drainage ditches. Discharges associated with irrigation facilities are included.
4. Construction of temporary sedimentation basins at construction sites if fill material is not placed in waters of the United States.
5. Activities for which a state has an approved program under Section 208 of the Clean Water Act for non-point pollution sources.
6. Construction or maintenance of farm roads, forest roads, or temporary mining roads. Best management practices must be followed to reduce flow pattern impairment and aquatic impacts (see regualtions for more information).