[Ord. No. 10546, 1-3-2019[1]]
The purpose of this article is to provide stormwater rules, regulations and standards to establish best management practices (BMPs) for infill development within the City of Kirkwood, Missouri, in order to promote the public health, safety, convenience and general welfare of the municipality.
[1]
Editor's Note: Pursuant to this ordinance, former Art. VII was renumbered as Article VIII.
[Ord. No. 10546, 1-3-2019]
As used in this article, the following terms shall have the meanings indicated:
BEST MANAGEMENT PRACTICE (BMP)
A structural device, measure, facility, or activity that helps to achieve stormwater management control objectives at a designated site.
IMPERVIOUS AREA (IA)
The portion of a parcel of property that is covered by any material, including without limitation roofs, streets, sidewalks and parking lots paved with asphalt, concrete, compacted sand, compacted gravel or clay, that substantially reduces or prevents the infiltration of stormwater. Impervious area shall not include natural undisturbed surface rock.
INFILL DEVELOPMENT STORMWATER GUIDANCE DOCUMENT
The latest edition of the manual "Stormwater Management Guidance, City of Kirkwood Green Infrastructure Techniques for Stormwater Management" maintained by the Department of Public Services.
LOT
A tract, plot or portion of a subdivision or parcel of land intended as a unit for the purpose, whether immediate or future, for transfer of ownership or for building development.
MAINTENANCE AGREEMENT
An agreement between the current property owner and the City where the property owner agrees to maintain any installed BMPs on the property.
NET ADDITIONAL IMPERVIOUS AREA
The impervious area calculated by subtracting the present impervious area in the most currently available aerial photography data or current site survey from the proposed post-development impervious area and maintaining the original property boundary as the regulated project boundary, regardless of subdivision, replat, horizontal property regime, or any other modification of property boundaries by deed or plat.
PLAN
A document approved at the site design phase that outlines the measures and practices used to control stormwater runoff at a site.
REGULATED INFILL DEVELOPMENT
The creation of net additional impervious area of at least 1,000 square feet or causing the total impervious area on the lot to be 25% or greater of the total lot area for commercial, industrial, or residential real property through new development, redevelopment, or rehabilitation of existing lots.
STORMWATER
Any surface flow, runoff and drainage consisting entirely of water from any form of natural precipitation and resulting from such precipitation.
VACANT LOT
Any lot containing no current permanent structure(s) and no permanent structures visible on the aerial photography dated 2001 maintained by the City.
[Ord. No. 10546, 1-3-2019]
(a) 
All regulated infill development shall not proceed without a permit and shall meet the requirements of this section.
(1) 
All regulated infill development creating 1,000 square feet or more of net additional impervious area is required to treat, by means of capture, the first 1.14 inches of rainfall runoff, for impervious area equal to the net additional impervious area. Vacant lots shall be subject to this requirement.
(2) 
All regulated infill development causing the total impervious area on the lot to be 25% of the total lot area are required to treat, by means of capture, the first 1.14 inches of rainfall runoff, for the amount of impervious area greater than 25% of the total lot area or the net additional impervious area, whichever is greater.
(3) 
All regulated infill development required to provide stormwater quality or quantity control BMPs by the Metropolitan St. Louis Sewer District MSD shall be exempt from the requirements of items in Subsection (a)(1) and (2) of this section.
(4) 
All new development and redevelopment sites that disturb greater than or equal to one acre, including projects that are part of a larger common parcel or project that is greater than one acre shall have development plans submitted to the Metropolitan St. Louis Sewer District (MSD) for review and approval prior to the issuance of any building permits.
(5) 
All development proposed for commercial, industrial, or multifamily use regardless of disturbed area shall have development plans submitted to the Metropolitan St. Louis Sewer District (MSD) for review and approval prior to the issuance of any building permits.
(6) 
Construction of an approved stormwater BMP(s) shall not require a separate permit if installed in conjunction with associated construction activities requiring a permit from the Department of Public Services.
(7) 
Approved stormwater BMP(s) constructed in association with any permitted work not requiring a residential site restoration escrow or performance guarantee shall require a stormwater BMP construction escrow as set forth in Chapter 5, Article VIII, Fee Schedule.
(8) 
All regulated infill development shall comply with the provisions of Chapter 5, Article V, of this code.
(9) 
All regulated infill development shall comply with all applicable provisions of Appendix A, Zoning Ordinance, Ord. No. 10103.
(b) 
The owner/developer of a project qualifying as regulated infill development shall endeavor to treat the first 1.14 inches of rainfall runoff from the net added impervious area using methods from the infill development stormwater guidance document. If this treatment proves impractical, improving downstream drainage to mitigate a known flooding problem with assistance from a professional engineer may be considered for all or part of the 1.14-inch treatment requirement; final determination of allowable alternate method to be made by Director of Public Services.
[Ord. No. 10546, 1-3-2019]
(a) 
All projects which include the installation of sump pumps or existing sump pumps with discharges causing a nuisance per Chapter 16, § 16-2, of this Code must discharge to one of the following BMPs per the infill development stormwater guidance document:
(1) 
Drywell sized to treat a minimum of 175 square feet of contributing area and located a minimum of 10 feet from any property line; or
(2) 
Vegetated filter strip sized to treat a minimum of 175 square feet of contributing area and sump pump discharge located a minimum of 20 feet from any property line.
(b) 
BMPs for sump pump discharges listed in this section may contribute to the required BMPs for regulated infill development by § 5-202.
[Ord. No. 10546, 1-3-2019]
The Director of Public Services shall maintain the "Stormwater Management Guidance, City of Kirkwood Green Infrastructure Techniques for Stormwater Management" as adopted by resolution by the City Council. The latest version as adopted by resolution by the City Council shall be followed by all persons planning or constructing regulated infill development within the City limits.
[Ord. No. 10546, 1-3-2019]
(a) 
Prior to the issuance of any permit for a development involving any regulated infill stormwater BMP, the owner(s) of the site must execute a maintenance agreement that shall be binding on all subsequent owners of land served by the stormwater BMP. The agreement shall provide for access to the BMP and the land it serves at reasonable times for periodic inspection by the City or the City's designee and for regular or special evaluations of property owners to ensure that the BMP is maintained in proper working condition to meet City stormwater requirements. The maintenance agreement shall be recorded with the St. Louis County Recorder of Deeds, and a recorded copy of the agreement shall be provided to the City by the owner prior to issuance of any permit.
(b) 
The owner(s) of every regulated infill development site shall be responsible for maintaining stormwater BMPs in an effective state as determined in the sole judgment of the City after completion of construction.
(c) 
Occupancy permits shall not be granted until all stormwater BMPs have been inspected and approved by the City.
[Ord. No. 10546, 1-3-2019; ]
Whenever the Director or the Director's designees, including inspectors within the City's Department of Public Services, find that a person has violated the terms of the maintenance agreement or failed to meet a requirement of this chapter, the Director or his or her designee may order compliance in accordance with procedures set forth in Chapter 5, Article III, Property Maintenance Code.
[Ord. No. 10546, 1-3-2019]
Violation of the provisions of this article or failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with granting of variances) shall be subject to penalties in accordance with Chapter 5, Article III, Property Maintenance Code.