Peoria, IL Environmental Rules: Stormwater Management (2026)

Any project that increases impervious area must control runoff under Sec. 5-29. Volume control practices must capture the first inch of runoff from impervious surfaces, using retention-based BMPs such as infiltration trenches, basins, porous pavement, or bioretention systems sized to retain and infiltrate that volume. Detention design must ensure the peak discharge rate for the 50 percent and four percent frequency storm events after development does not exceed pre-development rates. Engineers calculate flows using the City of Peoria Hydrologic and Hydraulic Guidelines and NRCS runoff methods, with major stormwater systems sized for the one percent (100-year) frequency storm and minor systems (curbs, storm sewers, ditches) sized for a ten-year event.

Maximum flow depth on roads and ponding depth in new parking lots is capped at 12 inches during the 100-year storm. Before any permitted activity begins, Sec. 5-2 requires a permit or license; initiating work without one draws a fine starting at $100 for a first offense, $300 for a second, and $500 for a third or subsequent offense within two years, and a contractor who racks up more than three violations in two years loses permitting privileges in the city for 12 months, plus a $200 reinstatement fee and a $300 fee to petition for early reinstatement before the administrative hearing officer. The public works official also has a standing right of access to inspect any stormwater detention basin found in danger of failure.