§ 28-21. Definitions.

The following words, when used herein, shall have the meanings indicated, unless the context clearly indicates otherwise:

Beneficiaries of drainage service shall include all developed real properties within the city which benefit by the provision of maintenance, operation and improvement of the stormwater control system. Such benefits may include, but are not limited to, the provision of adequate systems of collection, conveyance, detention, treatment and release of stormwater, the reduction of hazard to property and life resulting from stormwater runoff, improvement in general health and welfare through reduction of undesirable stormwater conditions and improvements to the water quality in the storm and surface water system and its receiving waters.

Commercial unit means any building or facility used other than as a dwelling unit or for industrial purposes and which has not been converted to equivalent dwelling units. It includes churches, schools and public facilities.

Contributors of drainage waters shall include all developed real properties within the city.

Developed shall mean any property altered in appearance by removal of vegetation, grading of the ground surface and construction of a structure or impervious surface.

Director means the director of the stormwater drainage utility, appointed or designated by the city manager.

Equivalent residential unit (ERU). The average impervious area in square feet of a residential unit within the city. The value of one ERU is two thousand nine hundred (2,900) square feet.

Fee shall mean the stormwater drainage utility fee enacted herein.

Hydrologic response means the manner and means by which stormwater collects upon real property and is conveyed from real property, and which is a function dependent upon a number of interacting factors, including, but not limited to, topography, vegetation, surficial geologic conditions, antecedent soil moisture conditions and groundwater conditions. The principal measures of the hydrologic system may be stated in terms of total runoff volume, as a percentage of total precipitation which runs off, or in terms of the peak rate of flow generated in the event of a storm of given duration and intensity, or statistical interval of return (frequency).

Impervious surfaces means those hard-surfaced areas which either prevent or retard the entry of water into soil mantle, as it entered under natural conditions prior to development, and/or cause water to run off the surface in greater quantities or at an increased rate of flow from that present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, rooftops, sidewalks, walkways, patio areas, driveways, parking lots, storage areas and other surfaces which similarly impact the natural infiltration or runoff patterns which existed prior to development, including normal water in ponds or lakes.

Multiple dwelling unit means a building or facility consisting of more than one (1) dwelling unit, each such unit consisting of one (1) or more rooms with bathroom and kitchen facilities designed for occupancy by one (1) family.

Open drainage way means a natural or man-made conveyance system which has the specific function of transmitting natural stream water or storm runoff water from a point of higher elevation to a point of lower elevation, such as swales, ditches, canals, streams, creeks and gutters.

Peak flow means the highest momentary rate of water flow, measured or estimated in cubic feet of water per second. It is differentiated from total flow volume by the introduction of a unit of time measure during which the maximum rate of flow is measured, calculated or estimated.

Runoff control is any means approved by the city engineer by which the peak rate of stormwater runoff from developed land surfaces is reduced and the erosion created by stormwater is reduced.

Total flow means the accumulative volume of water discharged from a property, basin or water shed. The total flow is quantified in measures such as acre feet or cubic feet of water.

Utility means the stormwater drainage utility created hereby.

(Ord. No. 1355, § 2, 4-17-2003)