accessIndiana

Hydromodification activities include earthmoving, construction and maintenance activities in or adjacent to waterbodies. Most states require permits, either independent of or related to Clean Water Act Section 404 permits, for certain activities to alter waterways or to maintain prior drainage ditches, dams or diversions, with the overall goal of protecting wetlands. Not all states apply these provisions to reduce nonpoint source pollution.

There are five basic categories of State permits: stream alteration, regulation of agricultural drainage, dam safety and operation, State wetlands, and floodplains. Permits for stream alterations often overlap with Section 404 permits, though States without such provisions can use Section 401 water quality certification to affect impacts on water quality.

Many States have laws providing detailed requirements for work in tidal and nontidal wetlands. Many regulations specify use of forestry and agricultural BMPs, permit requirements, prohibitions of certain activities and other enforceable requirements. Many State programs overlap some with Clean Water Act Section 404 permitting, but often cover activities in or near wetlands either not regulated or that would be permitted by a general permit.