A.    Purpose.  In order to promote the public health, safety, and general welfare of the citizens of the City of Ottawa, the purpose of this Article shall be to establish post-construction minimum stormwater management requirements and controls on any new development or redevelopment project(s) with subdivision or site plan applications.

B.    Objectives.  This Article seeks to meet this purpose through the following objectives:

1.    Minimize increases in stormwater runoff from any development in order to reduce non-point source pollution, siltation, and streambank erosion and maintain the integrity of stream channels;

2.    Minimize increases in non-point source pollution caused by stormwater runoff from development which would otherwise degrade local water quality, particularly if receiving bodies are classified as impaired on the most recent version of the 303d listing of impaired waters in Kansas as identified by KDHE;

3.    Reduce stormwater runoff rates, soil erosion, and non-point source pollution, wherever possible, through stormwater Best Management Practices (BMPs) and to ensure that these BMPs are properly maintained and pose no threat to public safety.

Within this Article, the term Stormwater Management Facility shall mean BMPs that are implemented or constructed in order to comply with this Article.

(Code 2015; Ord. 4001-18)

A.    Applicability.  This section is applicable to development and redevelopment projects for commercial, industrial and new residential subdivisions that disturb 1 acre or greater or increase net impervious surfaces by 500 square feet or greater.

B.    Exemptions.  Owners of properties where the following activities are undertaken are exempt from the stated requirements.

1.    Farming activities;

2.    Unplanned emergency work and emergency repairs necessary to protect life or property.

C.    Waivers.  All or some of the required stormwater management facility standards may be waived by the City under the following circumstances:

1.    If it can be demonstrated that the proposed development is not likely to impair attainment of the objectives of this ordinance; or

2.    The City of Ottawa finds that meeting the minimum on-site management requirements is not feasible due to the natural or existing physical characteristics of the site; or engineering studies determine that installing a stormwater management facility in order to meet the stormwater management standard(s) will cause adverse impact to water quality, or cause increased channel erosion, or downstream flooding.

(Code 2015; Ord. 4001-18)

A.    Technical Specifications and Design Criteria

1.    Unless specifically stated and amended by a formal written policy statement by the City Manager, all stormwater management facilities required or constructed shall be designed and constructed in accordance with the latest edition of the Manual of Best Management Practices for Stormwater Quality (Mid-America Regional Council and American Public Works Association), with exceptions as adopted by the City of Ottawa, Manual of Best Management Practices for Stormwater Quality is hereby incorporated by reference into this Article.  Other best Management Practices (BMP) manuals may be used to provide supplemental design guidance with approval by the City Engineer, provided that all of the treatment requirements of this article are met.

2.    Required water quality treatment shall be calculated based on treating the Water Quality Volume (WQv) from 100 percent of the new development area, or 100 percent of the redevelopment area less previously developed portions that remain unaltered.  The WQv will be based on the 90-percent Water Quality Rainfall Event for Ottawa as designated by the City.  BMPs will be required to treat the entire WQv from the required treatment area.

3.    If hydrologic or topographic conditions, receiving stream water quality or regulatory status warrant greater control than provided by the minimum control requirements set forth in the Manual of Best Management Practices for Stormwater Quality, the City Manager or his/her designee may impose additional requirements deemed necessary to control the pollutants in stormwater runoff.  It shall be unlawful for any person to fail to comply with any additional requirements imposed by the City Manager or his/her designee as necessary to control the pollutants.  Water quality or regulatory status includes but is not limited to water bodies with Total Maximum Daily Loads (TMDL), that are tributary to TMDL bodies, that are experiencing exceedances of Kansas Surface Water Quality Guidelines, or are otherwise designated in the City’s Municipal Separate Storm Sewer (MS4) Permit.

B.    General Requirements for Stormwater Design Plans

1.    Stormwater management facility design information, including required post-construction water quality BMPs, shall be submitted as part of the preliminary plat, final plat, site plan and construction plans, in accordance with the policy and requirements established by the Community Development Department pertaining to the Stormwater Management Study.

C.    Conformity to the Approved Plans

1.    Grading designs shown on approved master grading plans and the design of stormwater management facilities and controls shown on approved design plans shall be adhered to during grading and construction activities, in accordance with the Erosion and Sediment Control Plan stated in Section 14-306.

2.    Grading and stormwater design plans shall be amended to meet all local ordinances and standards if the proposed site conditions change after plan approval is obtained, or if it is determined by the City during the course of grading or construction that the approved plan is inadequate.

D.    Provide an Operations and Maintenance Plan

1.    An Operations and Maintenance Plan shall be included with the stormwater management facility design information submitted with the construction plan.  The Operations and Maintenance Plan shall include the required operation and maintenance provisions, maintenance and inspection checklist for each stormwater management facility and water volume area that is serving, or will serve, the development or redevelopment.

2.    A statement shall be included on the final plat and/or site plan that indicates the owner(s) responsibility for operation, maintenance, and inspection of the stormwater management facility(s) per Section 14-403.

E.    Provide Stormwater Construction Information on As-Built Drawings

1.    Completed as-built drawings shall be provided to the Community Development Department and shall include sufficient design information to show how the stormwater management facilities operate as designed under the approved stormwater management study.

2.    The as-built drawings shall be prepared and stamped by a Professional Engineer licensed to practice in the State of Kansas.

(Code 2015; Ord. 4001-18; Ord. 4025-19)

A.    Maintenance Responsibility.  The landowner of the property on which the stormwater management facility(s) has been constructed pursuant to this Article, or any other person or agent in control of such property, shall maintain in good condition and promptly repair and restore all grade surfaces, walls, drains, dams and structures, vegetation, erosion and sediment control measures, and other protective devices. Such repairs or restoration and maintenance shall be in accordance with approved plans.

1.    Maintenance Schedule.  A maintenance schedule shall be developed for any stormwater management facility(s) and shall state the maintenance to be completed, the time period for completion, and who shall perform the maintenance.  This maintenance schedule shall be incorporated into the maintenance agreement and shall be followed by subsequent responsible parties.

2.    Pollutant Removal for Maintenance.  The removal of pollutants, sediment, and/or other debris for the purpose of maintenance of stormwater management facilities shall be performed in accordance with all City, State, and Federal laws.

3.    Preserve Approved Grading Designs. Re-grading an individual lot or lots, or portions of a lot or lots, in a manner that is not in accordance with the approved master grading plan, such that the direction(s) of stormwater runoff is altered from the direction that would occur under the approved master grading plan, shall be considered in violation of this Article.

4.    Preserve Existing Drainage Paths.  Blockage of a channel, ditch, stream, any other drainage path or stormwater management facility shall be considered a violation of this Article.

(Code 2015; Ord. 4001-18)

A.    Inspection.

1.    Notice by City.  The City may periodically inspect these privately-owned stormwater management facility(s).  If the stormwater management facility is not operating as shown in the as-built drawing, or should conditions be found that cause or may cause the pollution of downstream receiving waters or the flooding of adjacent or downstream properties, the City may issue a notice of violation in accordance with the enforcement provisions in Article I, Section 14-104.  The City may order the property owner(s) to perform corrective actions as are necessary to implement the proper operation of these facilities for the purposes of flood prevention, public safety, and/or to ensure compliance with jurisdictional regulatory conditions.

2.    After Construction.  Once the site has been stabilized and construction has ceased, the property owner or his/her appointed designee shall conduct routine inspections for the stormwater management facility(s) based on the guidance provided in the Operations and Maintenance Plan.

3.    Reports.  After construction on the property is complete, the property owner(s) shall provide to the City, on an annual basis, a completed and signed copy of the inspection report for each stormwater management facility that is included with the Operations and Maintenance Plan for the property.  The inspection report is due every two years after the date (month and day) of approval of the as-built plan for the property.

4.    Records.  The property owner(s) shall make available upon request any self-inspection reports, monitoring/maintenance records, compliance evaluations, notices of intent, and any other records, reports, receipts, and other documents related to compliance with this Article with any related City, State, or Federal permit.

5.    Access Easement.  All City maintained open channels must have a minimum 20-foot wide maintenance access on each side of the stream as measured from the top-of-bank of each side of the stream.

(Code 2015; Ord. 4001-18; Ord. 4025-19)

Enforcement, penalties, and administration for violations shall be managed by Article I, Section 14-104.

(Code 2015; Ord. 4001-18; Ord. 4025-19)