Standards for implementing stormwater best management practices.
Columbus City Codes § 3372.907
in effect3372.907 - Standards for implementing stormwater best management practices.
Development of a lot or parcel within the Hellbranch Run watershed overlay is subject to the following general principles intended to implement stormwater best management practices within the development site. The director of Columbus Water & Power shall promulgate through regulations standards to implement these general principles.
A. Detention and Treatment. Stormwater generated as the result of development shall be managed using best management practices such as extended detention, natural or constructed wetlands, or other approved means to the extent necessary to meet water quality pollutant removal goals, reduce channel erosion, prevent overbank flooding, and pass extreme floods. The applicant shall demonstrate that the stormwater management practices for the development site are designed to:
1. Capture and treat 90 percent of the average annual stormwater runoff volume (water quality volume - WQv);
2. Provide 24-hour extended detention of the post-developed one year, 24-hour storm event (channel protection storage volume - Cpv);
3. Control the peak discharge of the post-development runoff volume from the ten-year, 24-hour storm event to the ten-year predevelopment peak discharge rate (overbank flood protection discharge volume) unless a watershed hydraulic model indicates the ten-year control is not needed on the site; and
4. Control the peak discharge of the post-development runoff volume from the 100-year, 24-hour storm event to the 100-year pre-development peak discharge rate (extreme flood volume - Qf), unless the site is smaller than five acres or a regional flood model indicates the 100-year control is not needed for the site.
B. Conveyance. All stormwater generated as the result of development shall flow into the nearest receiving stream or approved storm sewer drainage system without increasing flood depths or causing standing water either upstream or downstream. To assure that this goal will be achieved, the applicant must affirmatively demonstrate that: between the proposed development site and the point in the receiving watercourse at which the proposed development site is ten percent of the total area tributary, post-development stormwater peak rate of runoff for the ten-year, 24-hour storm event will be less than or equal to the pre-development stormwater peak rate of runoff.
(Ord. 2431-03 § 41; Ord. 0854-2008 § 47; Ord. No. 1882-2026, § 1, 6-29-2026.)
Source: City of Columbus, City Codes and City Charter (Municode Library, library.municode.com)URL: https://library.municode.com/oh/columbus/codes/code_of_ordinances?nodeId=TIT33ZOCO_CH3372PLOV_3372.907STIMSTBEMAPRFetched: 10/27/2026