(A) Purpose. The purpose of this section is to establish stormwater management regulations that reduce the volume and rate of stormwater runoff entering the storm sewer system and help prevent flood damages.
(B) Applicability. The standards of this section shall apply to all development that meets the criteria stated in § 1250.01(B) (Applicability). The standards of this section shall not replace any stormwater management controls required by any other agency. If any development is subject to the standards of this section as well as the stormwater management requirements of another regulating agency, the standards of this section shall be met in addition to any applicable requirements of such agency. If the provisions of this section are inconsistent with the stormwater management requirements of another regulating agency, the more restrictive provision shall govern.
(C) Stormwater management controls.
(1) Runoff detention. All stormwater conveyance and retention measures shall be designed to manage the 50-year, 24-hour return frequency storm event and to provide measures to manage and direct overflows to the public right-of-way. Detention shall be achieved through incorporation of green infrastructure, post-construction stormwater management measures, and BMPs designed to increase permeable areas and to reduce pollution. Detention shall be provided as part of a stormwater management plan to accommodate the allowable size of a stormwater connection to the city sewer system.
(2) Discharge rate. The maximum allowable discharge rate shall be 0.15 cubic feet per second per acre (cfs/ac). The maximum discharge rate (cfs) from the regulated development shall be based on the maximum release rate (cfs/ac) times the disturbed land area (ac).
(3) Sheet flow. Runoff from impervious surface area shall not sheet flow to the public right-of-way.
(4) Fee-in-lieu. Any property may satisfy city stormwater management requirements for any use through payment of a fee-in-lieu of providing stormwater management controls, subject to approval by the Zoning, Planning, and Development Commission and in conformance with the following standards. This provision shall not be allowed in-lieu of stormwater management controls required by any other agency except those required by this chapter.
(a) Approval required. The Zoning, Planning, and Development Commission may approve or deny any application for fee-in-lieu based on the following criteria:
1. Approval will facilitate new development or redevelopment of property.
2. Approval will remedy constraints in providing the required stormwater management controls due to lot size and configuration.
(b) Dedicated stormwater management fund. The fee required shall be based upon a calculation made by the Department of Public Works for construction and ongoing maintenance of the required on-site controls. Such payment shall be placed into a dedicated stormwater management fund to be used by the city for the acquisition, construction, and maintenance of stormwater management controls within the same general area as the property for which the fee was collected.
(c) Certificate of waiver. Evidence of the issuance of a stormwater management controls waiver shall be in the form of a certificate of waiver, recorded with the Cook County Recorder of Deeds at the property owner's expense and issued in the name of the property owner to which the waiver is granted. Full payment shall be made in advance to the dedicated stormwater management fund as a condition of the certificate of waiver issued by the city and prior to issuance of a certificate of occupancy.
(d) Applicability of certificate. The certificate of waiver shall be applicable only for the limits of the development for which it is issued. New development or additions, or any construction that results in applicability of this section, shall be required to comply with the parking requirements for said additions or obtain another waiver.
(5) Operations and maintenance plan. Maintenance of stormwater management facilities located on private property shall be the responsibility of the property owner. An operations and maintenance plan (O&M plan) must be signed by the owner and notarized, and submitted to the city. A copy of the O&M plan must be provided to each new owner before the sale is finalized, and the O&M plan must be signed by the new owner, notarized, and submitted to the city to be kept on record. The O&M plan shall include the following:
(a) Maintenance easement. Prior to approval of a stormwater management plan, the applicant must execute a maintenance easement agreement that shall be binding on all subsequent landowners served by the stormwater management facility. The easement shall provide for access to the facility at reasonable times for periodic inspection by the city to ensure that the facility is maintained in proper working condition to meet design standards and any other provisions established by this chapter. The easement shall be recorded by the grantor with the Cook County Recorder of Deeds after approval by the city.
(b) Maintenance after construction. The owner or operator of permanent stormwater management facilities installed in accordance with this chapter shall be responsible for the operation and maintenance of such facilities to achieve the goals of this chapter. Proper operation and maintenance shall include, at a minimum, the following:
1. A preventative/corrective maintenance program for all critical facilities and systems of treatment and control (or related appurtenances) which are installed or used by the owner or operator to achieve the goals of this chapter.
2. Written procedures for training personnel in the operation and maintenance of the facilities.
3. Discharge from facilities shall not exceed design criteria or cause or contribute to water quality standard violations.
(Ord. 17-31, passed 9-12-2017)