(A) Purpose and intent. The City of Lake Mary Stormwater Management System Maintenance Requirements are to provide for effective management of stormwater run-off within the city; and provide a mechanism for mitigating the damaging effects of uncontrolled and unplanned stormwater run-off; to improve the public health, safety and welfare by providing for the safe and efficient capture and conveyance of stormwater and the correction of stormwater problems.
(B) Definitions.
(1) “DRY DETENTION.” A system designed to collect and temporarily store stormwater in a normally dry basin with subsequent gradual release of the stormwater.
(2) “EXFILTRATION TRENCH.” A below ground system consisting of a conduit such as perforated pipe surrounded by natural or artificial aggregate which is utilized to percolate stormwater into the ground.
(3) “LITTORAL ZONE.” That portion of a wet detention pond that is designed to contain rooted aquatic plants.
(4) “OPERATIONAL MAINTENANCE.” Any activity or repair required to keep a stormwater management system functioning as designed.
(5) “POLLUTION.” The presence in waters of any substances, contaminates, or manmade or man-induced impairment of waters or alteration of chemical, physical, biological, or radiological integrity of water in quantities or at levels which are or may be potentially harmful or injurious to human health or welfare, animal or plant life, or property or which unreasonably interfere with the enjoyment of life or property.
(6) “RETENTION.” A system designed to prevent the discharge of a given volume of stormwater runoff into surface waters by complete on-site storage.
(7) “STORMWATER MANAGEMENT SYSTEM.” a system which is designed and constructed or implemented to control discharges which are necessitated by rainfall events, incorporating methods to collect, convey, store, absorb, inhibit, treat, use or reuse water to prevent or reduce flooding, overdrainage, environmental degradation and water pollution or otherwise affect the quality and quantity of discharges.
(8) “SWALE.” A manmade trench which has a top width to depth ratio of the cross-section equal to or greater than 6:1, or side slopes equal to or greater than three feet horizontal to one foot vertical and contains contiguous areas of standing or flowing water only following a rainfall event and is planted with or has stabilized vegetation suitable for soil stabilization, stormwater treatment, and nutrient uptake; and is designed to take into account the soil erodibility, soil percolation, slope, slope length and drainage area so as to prevent erosion and reduce pollutant concentration of any discharge.
(9) “UNDERDRAIN.” A drainage system installed beneath a stormwater holding area to improve the infiltration and percolation characteristics of the natural soil when permeability is restricted due to periodic high water table conditions or the presence of layers of fine textured soil below the bottom holding area.
(10) “WET DETENTION.” The collection and temporary storage of stormwater in a permanently wet impoundment in such a manner as to provide for treatment through physical, chemical and biological processes with subsequent gradual release of stormwater.
(C) Monitoring and operational maintenance requirements. The following operational maintenance activities shall be performed by the property owner on all systems on a regular basis or as needed:
(1) Removal of trash and debris,
(2) Inspection of inlets and outlets,
(3) Removal of sediments when storage volume or conveyance capacity of the stormwater management system is below design levels,
(4) Stabilization and restoration of eroded areas.
(D) Specific operational requirements.
(1) Retention, swale and underdrain systems shall include provisions for:
(a) Mowing and removal of grass clippings,
(b) Aeration, tilling, or replacement of topsoil as needed to restore the percolation capability of the system. If tilling or replacement of topsoil is utilized, vegetation must be established on the disturbed surface.
(2) Exfiltration systems shall include provisions for removal of sediment and debris from sediment sumps.
(3) Dry detention systems shall include provisions for mowing and removal of grass clippings.
(4) Wet detention systems shall include provisions for operational maintenance of the littoral zone. Replanting shall be required if the percentage of vegetative cover falls below the original permitted level. It is recommended that native species be maintained in the littoral zone as part of the system's operation and maintenance plan. Undesirable species such as cattails and exotic plants should be controlled if they become a nuisance.
(5) If the system is not functioning as designed and permitted, operational maintenance must be performed immediately by the property owner to restore the system.
(Ord. 1464, passed 5-17-12)