As used in this chapter:
(a) "Channel" means a natural or artificial watercourse which, continuously or periodically, contains moving water or which forms a connecting link between two bodies of water. It has a defined bed and banks which confine the water.
(b) "Channel flow" means the water flowing within the limits of the defined channel.
(c) "Developer" means any person who acts in his or her own behalf or as the agent or an owner of property and who engages in the alteration of land or vegetation in preparation for or in undertaking construction activity.
(d) "Development" means any alteration of land or vegetation in preparation for or in undertaking construction activity.
(e) "Drainageway" means a route or course along which water moves or may move to drain an area.
(f) "Emergency flow way" means the flow routes and drainageway necessary to convey the 100-year storm through a development.
(g) "Emergency spillway" must be included with all retention/detention basin designs. SCS methods must be utilized in the design. A design frequency of 100 years must be used.
(h) "Erosion" means the process by which the land surface is blown away by the action of water, wind, ice or gravity.
(i) "Fence" means a structure required around all storm water facilities, as required by Planning Commission.
(j) "Flood" means a general and temporary condition of partial or complete inundation of normally dry land areas from:
(1) The overflow of inland or tidal waters; and/or
(2) The unusual and rapid accumulation or runoff of surface waters from any source.
(k) "Floodway" means the channel of a watercourse and the adjacent land areas that have been reserved in order to pass the base flood discharge.
(l) "Grassed waterway" means a broad and shallow natural course or constructed channel covered with erosion resistant grasses or similar herbaceous cover and used to conduct surface water.
(m) "Hydrologic and hydraulic study" means an engineering study utilizing SCS TR 55, 1986 edition or latest edition, to determine rates, volumes and distribution of storm runoff, and its collection, storage and conveyance.
(n) "Runoff" means the portion of rainfall, melted snow or irrigation water that flows across the ground surface and eventually is returned to streams. Specifically:
(1) "Accelerated runoff" means increased runoff due to less permeable surface area primarily caused by urbanization.
(2) "Peak rate of runoff" means the maximum rate of runoff for any storm.
(3) "Runoff volume" means the total quantity or volume of runoff during a specified time period. It may be expressed in acres-feet or in inches-depth of the drainage area, or in other units of volume.
(o) "Storage" means the control, retention or detention of runoff. Specifically:
(1) "Detention storage" means the storm runoff collected and stored for a short period of time and then released at a controlled rate (dry pond).
(2) "Retention storage" means storm runoff collected and stored for a short period of time and which is released at a controlled rate, leaving in the facility a permanent pool of water. This facility is often associated with water related recreational or aesthetic uses (wet pond).
(p) "Storage facility" means any facility used to store, retain or detain storm runoff, including, but not limited to, retention and detention storage facilities, underground pipes, rooftop or parking lot storage, basins, depressions and pools.
(q) "Storm frequency" means the average period of time in which a storm of a given duration and intensity can be expected to be equaled or exceeded.
(r) "Storm drainage system" means the surface and subsurface system for the removal of water from the land, including both the natural elements of streams, gullies, ravines, marshes, swales and ponds, whether of an intermittent or continuous nature, and man-made elements which include conduits and appurtenant features, culverts, ditches, channels, storage facilities, streets and the storm sewerage system. Specifically:
(1) "Initial drainage system" means that part of the storm drainage system which is used regularly for collecting, transporting and disposing of storm runoff, snow melt and miscellaneous minor flows. The initial system is also termed the "convenience system," "minor system," or "storm sewerage system," and may include many features ranging from curbs and gutters to storm sewer pipes and open drainage ways.
(2) "Major drainage system" means that storm drainage system which carries the runoff from a storm having a frequency of occurrence of once in 100 years. The major system will function whether or not it has been planned and designed and whether or not improvements are situated wisely in respect to it. The major system is also termed the "emergency flow way." The major system usually includes many features, such as streets, ravines and major drainage channels. Storm sewerage systems may reduce the flow in many parts of the major system by storing and transporting water underground.
(s) "Stream" means a course of running water, usually flowing in a particular direction and in a definite channel, and discharging into some other stream or body of water.
(t) "Watercourse" means a channel in which a flow of water occurs either continuously or intermittently in a definite direction. The term applies to either natural or artificially constructed channels.
(Ord. 05-79. Passed 6-7-05.)