Are subdivisions under one acre exempt from Rule 5?

Only if they are not part of a larger common plan of development. Lots within a planned subdivision are aggregated, so individual half-acre lots in a 10-acre development still require Rule 5 coverage.

Who enforces Rule 5 locally?

IDEM delegates inspection authority to county Soil and Water Conservation Districts and qualifying MS4 communities, but the underlying state rule applies uniformly across all 92 counties.

Indiana Erosion Control Law: Statewide Environmental Rules Rules (2026)

Key Facts

Governing rule: 327 IAC 15-5
Acreage trigger: 1 acre disturbance
NOI lead time: 48 hours minimum
Final stabilization: 70 percent cover
Inspection frequency: Weekly plus rain events

Full Breakdown

Rule 5 applies to all construction activity in Indiana disturbing one or more acres of land, or smaller sites part of a larger common plan of development. Operators must submit a Notice of Intent at least 48 hours before earth-disturbing activity, prepare a Stormwater Pollution Prevention Plan (SWPPP) addressing erosion controls, sediment controls, stabilization timelines, and post-construction measures, and conduct weekly self-inspections plus inspections after qualifying rain events. Soil and Water Conservation Districts and delegated MS4s perform field reviews. Final stabilization with 70% vegetative cover is required before terminating coverage.

Violations & Penalties

Failure to submit a Notice of Intent, missing SWPPP elements, or unstabilized sediment discharges can trigger IDEM enforcement, stop-work orders, and penalties up to $25,000 per day per violation.

Indiana Rule 5 Construction Stormwater Erosion Control

Key Facts

Full Breakdown

Violations & Penalties

Frequently Asked Questions

Sources

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