Kenner, LA Environmental Rules: Stormwater Management (2026)

City Code § 13-53 sets the drainage-detention standard for growth in the City of Kenner, a city built largely on drained wetlands where soil subsidence makes flood control non-negotiable. Any development other than single-family, totaling 10,000 square feet or more of land area counting all phases, and any single-family residential development of five acres or more, must hold the ten-year storm event post-development runoff rate at or below the pre-development rate. Compliance is achieved through on-site detention engineered so the release rate never exceeds the pre-development rate, using design concepts consistent with the Jefferson Parish 'Storm Drainage Design Manual' (1981 and later revisions) and the parish's 'Parking Lot Storm Runoff Detention Manual.' Before construction, the developer must submit drainage design calculations and a drainage map to the Department of Public Works, tracing the existing drainage system from the site outfall to the receiving outfall canal, plus calculations showing how the detention facility performs in a 100-year storm event.

Those calculations must cover drainage basin characteristics, system hydraulics, and any upstream or downstream influences, along with ten-year pre- and post-development flows, the release facility's volume-versus-depth performance, maximum water depth in the detention facility, and how the system will be maintained long-term. Culvert design velocity follows the Jefferson Parish manual's criteria unless the outlet ditch is paved. The Director of the Department of Public Works reviews and must approve every covered development before the city issues permits to proceed, making detention-plan approval a hard prerequisite to breaking ground rather than an afterthought.