Indiana SWPPP inspection requirements
- Rain trigger
- 0.5″ storm event
- Post-rain deadline
- By the end of the next business day after a qualifying storm (max three storm inspections per week)
- Routine inspections
- Every 7 days
- Permit
- Construction Stormwater General Permit (INRA00000)
- Agency
- Indiana Department of Environmental Management (IDEM)
How Indiana handles construction stormwater
Construction sites in Indiana disturbing one acre or more need coverage under the Construction Stormwater General Permit (INRA00000), administered by Indiana Department of Environmental Management. A qualifying event is 0.5″ in 24 hours; the inspection is due by the end of the next business day (weekends excluded), capped at three storm inspections per week, with at least one inspection per work week regardless of rain. Monthly allowed for areas stabilized with permanent vegetation. The current permit expires December 17, 2026 — re-verify at reissuance.
Inspector qualifications
A "trained individual" as defined in Appendix B of the CSGP — no third-party certification mandated.
Official sources
Common questions
What triggers a SWPPP inspection in Indiana?
Under the Construction Stormwater General Permit (INRA00000), a storm event of 0.5 inches or more triggers a post-storm inspection, by the end of the next business day after a qualifying storm (max three storm inspections per week). Routine inspections: every 7 days.
Who can perform SWPPP inspections in Indiana?
A "trained individual" as defined in Appendix B of the CSGP — no third-party certification mandated.
Who administers the construction stormwater program in Indiana?
Indiana Department of Environmental Management (IDEM) administers the NPDES construction stormwater program in Indiana under the Construction Stormwater General Permit (INRA00000).
What are the penalties for SWPPP violations in Indiana?
Federal Clean Water Act civil penalties can reach $68,445 per day per violation, and IDEM can issue administrative orders and state penalties on top. Missing rain-triggered inspections is among the most commonly cited violations in stormwater audits.
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