Noblesville, IN Environmental Rules: Erosion Control (2026)

Erosion and sediment control on construction sites in Noblesville sits at the intersection of three frameworks: federal (40 CFR 122.26 NPDES construction stormwater regulations), state (the IDEM Construction Stormwater General Permit, formerly known as 'Rule 5' under 327 IAC 15-5 before transition to the CSGP on December 18, 2021), and local (Chapter 52 of the Noblesville City Code, Section 52.34 SWPPP requirements, and the Noblesville Stormwater Technical Standards Manual). The CSGP trigger is land disturbance of one acre or more, or less than one acre if part of a larger common plan of development or sale. The project operator files a Notice of Intent (NOI) with IDEM, prepares a SWPPP signed by a trained individual, and submits the SWPPP to Noblesville Engineering for review under Section 52.34 before clearing or grading begins. Required EPSC measures on covered sites include perimeter silt fence at down-gradient edges, inlet protection at every storm drain and curb inlet, stabilized construction entrances with rock pads, sediment traps or basins sized per the Indiana Storm Water Quality Manual, concrete washout containment, dewatering controls, riparian buffer protection along Cicero Creek and the White River, and prompt temporary or permanent stabilization of disturbed areas (typically within 7 days of last disturbance under the CSGP). The SWPPP must remain on site, must be updated with inspection records weekly and after every 0.5-inch or greater rainfall, and must be available to City inspectors and IDEM inspectors. As of HEA 1037 (effective May 1, 2025, codified at IC 36-1-3-14), Noblesville and other Indiana MS4 ordinances cannot impose construction stormwater standards more stringent than the IDEM CSGP. SWPPP and erosion-control questions go to the MS4 Coordinator at (317) 776-6330.