We provide expert permitting services for construction activities within designated floodways. From hydrologic modeling to IDNR coordination, we guide your project from concept to approval.
A floodway is the channel of a river or stream and the adjacent land areas that must remain unobstructed to safely carry and discharge floodwaters. Construction in a floodway requires special review and approval to ensure flood risks are not increased.
Permits are required for any construction, excavation, or filling activity in a designated floodway. In Indiana, this includes obtaining approval from the Department of Natural Resources (IDNR) under 312 IAC 10.
Activities requiring floodway review include culvert or bridge installation, utility crossings, grading, berms, buildings, fencing, and stockpiling of materials within a mapped floodway.
We manage the entire floodway construction permit process—from identifying floodplain boundaries and preparing application documents to coordinating with IDNR and responding to review comments.
Permit applications typically require engineered site plans, floodplain modeling, cross-sections, construction details, and hydrologic and hydraulic (H&H) calculations to demonstrate no adverse impact.
We coordinate floodway construction approval with related permits such as Rule 5 (construction stormwater), Section 401/404 (wetlands/waters), and local MS4 requirements to streamline project timelines.
We have experience with challenging locations including stream crossings, former gravel pits, and industrial redevelopment projects where floodway boundaries intersect critical infrastructure.
Once your floodway construction permit is approved, we support you with construction-phase inspections, as-built documentation, and permit closeout reporting.
Our team stays up to date on changes to floodplain rules, FEMA map revisions, and state-specific permitting trends, allowing us to anticipate issues and keep your project on track.
Floodway permits typically require the following documentation: