Stormwater Regulations, Permitting, and Related Information

Stormwater Permitting

The Stormwater Program is responsible for issuing permit coverage and monitoring compliance for stormwater associated with industrial activity, construction activity, and municipal separate storm sewer systems (MS4s).

• Construction Stormwater General Permit (CSGP):
  • IDEM administers a general permit program that targets construction activities that are associated land disturbance of one (1) acre or more. The construction stormwater program is intended to reduce pollutants, principally sediment, that are a result of soil erosion and other activities associated with land-disturbing activities.
  • An option for the general public to view projects with permit coverage under the CSGP is available on nSITE Explorer.
  • Applications to obtain permit coverage is available online through the IDEM Regulatory ePortal. Under the new CSGP, online applications are required.
  • Stormwater Program Transition to Master General Permits
• Industrial Stormwater Permitting (327 IAC 15-6):
  • IDEM administers a general permit program that targets stormwater run-off associated with industrial activities. Requirements of this rule apply to specific categorical industrial facilities, which are exposed to stormwater.
• Municipal Separate Storm Sewer Systems:
  • IDEM administers a stormwater program that specifically targets local cities, towns, universities, colleges, correctional facilities, hospitals, conservancy districts, homeowner's associations and military bases located within urbanized areas, as defined by the U.S. Census Bureau. These designated entities are or MS4s are required to develop of a local stormwater program. Most MS4s in Indiana operate under a general MS4 permit, while several others, based on population are issued individual permits.
  • Stormwater Program Transition to Master General Permits