AS BUILT DRAWINGS: Design plans which have been revised to reflect all changes to the plans which occurred during construction.
BEST MANAGEMENT PRACTICES (BMP): Physical, structural and/or managerial practices that, when used singly or in combination, prevent or reduce pollution of water.
BOND: A surety bond, cash deposit or escrow account, assignment of savings, irrevocable letter of credit or other means acceptable to or required by the permit authority to guarantee that work is completed in compliance with the project's drainage plan and in compliance with all local government requirements.
CITY: The city of Hayden Lake, Kootenai County, Idaho.
CITY CLERK: The city clerk/treasurer of the city of Hayden Lake, Kootenai County, Idaho, or other officer of the city who is the custodian of the records of the proceedings of the city council, or his successor in functions, if any.
CITY ENGINEER: The engineer or engineering firm selected by the mayor and city council to act as city engineer for the city.
CLEARING: The destruction and removal of vegetation by manual, mechanical or chemical methods.
CONVEYANCE: A mechanism for transporting water from one point to another, including pipes, ditches and channels.
CONVEYANCE SYSTEM: The drainage facilities, both natural and manmade, which collect, contain and provide for the flow of surface and stormwater from the highest points on the land down to a receiving water. The natural elements of the conveyance system include swales and small drainage courses, streams, rivers, lakes and wetlands. The humanmade elements of the conveyance system include gutters, ditches, pipes, channels and most retention/detention facilities.
DESIGN STORM: A rainfall event of specific return frequency and duration that is used to calculate the runoff volume and peak discharge rate.
DETENTION: The temporary storage of storm runoff in a BMP, which is used to control the peak discharge rates, and which provides gravity settling of pollutants.
EROSION: The wearing away of the land surface by running water, wind, ice or other geological agents, including such processes as gravitational creep. Also, detachment and movement of soil or rock fragments by water, wind, ice or gravity.
EROSION/SEDIMENTATION CONTROL: Any temporary or permanent measures taken to reduce erosion, control siltation and sedimentation and ensure that sediment-laden water does not leave the site.
GROUNDWATER: Water in a saturated zone or stratum beneath the land surface or a surface water body.
IMPERVIOUS SURFACE: A hard surface area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development, and/or hard surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads, packed earthen materials and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater. Open, uncovered retention/detention facilities shall not be considered as impervious surfaces.
INFILTRATION: The downward movement of water from the surface to the subsoil. The infiltration capacity is expressed in terms of inches/hour.
INTERMITTENT STREAM: A stream or portion of a stream that flows only in direct response to precipitation. It receives little or no water from springs and no long continued supply from melting snow or other sources. It is dry for a large part of the year, ordinarily more than three (3) months.
LAND DISTURBING ACTIVITY: Any activity that results in a more than a fifteen percent (15%) change in the existing soil cover (both vegetative and nonvegetative) and/or the existing soil topography. Land disturbing activities include, but are not limited to, demolition, construction, clearing, grading, filling and excavation.
NUTRIENTS: Essential chemicals needed by plants or animals for growth. Excessive amounts of nutrients can lead to degradation of water quality and algal blooms. Some nutrients can be toxic at high concentrations.
QUALIFIED, LICENSED PROFESSIONAL: Licensed engineer, landscape architect, architect, soil scientist or other individual who has demonstrated a professional ability to design stormwater systems and certify their effectiveness with a registered stamp.
RECONSTRUCTION: Road reconstruction shall be considered any modification of the cross section or subgrade. Paving or repaving shall not be considered reconstruction.
RETENTION: The holding of runoff in a basin without release except by means of evaporation, infiltration or emergency bypass.
RUNOFF: Water originating from rainfall and other precipitation that is found in drainage facilities, rivers, streams, springs, seeps, ponds, lakes and wetlands, as well as shallow groundwater.
SEDIMENT: Fragmented material that originates from weathering and erosion of rocks or unconsolidated deposits, and is transported by, suspended in or deposited by water.
SEDIMENTATION: The deposition of sediment or ground surfaces and in watercourses.
STORM FREQUENCY: The time interval between major storms of predetermined intensity and volumes of runoff for which storm sewers and other structures are designed and constructed to handle hydraulically without surcharging and backflooding, e.g., a 2-year, 25-year or 100-year storm.
SWALE: A shallow drainage conveyance or infiltration area with relatively gentle slopes, generally with flow depths less than one-half foot (1/2').
TREATMENT BMP: A BMP that is intended to remove pollutants from stormwater. A few examples of treatment BMPs are detention ponds, oil/water separators, biofiltration swales and construction wetlands.
UNIQUE SITE CHARACTERISTICS: Soil, slope or depth to bedrock conditions that will not accommodate on site treatment through infiltration to the standards specified in the ordinance. (Ord. 117, 6-24-1993)
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