For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
"BANKFUL ELEVATION." The water level, or stage, at which the stream, river, or lake is at the top of its banks and any further rise would result in water moving into the floodplain.
"BEST MANAGEMENT PRACTICES (BMP)." A schedule of activities, prohibitions of practices, maintenance procedures, and other management practices, which are proven to be effective in preventing or reducing runoff, erosion, and sedimentation.
"BUFFER ZONE." The are defined from the bankful elevation extending toward a construction activity that shall be protected from disturbance.
"DETENTION FACILITY." Any structure which is designed to collect and store surface water for subsequent gradual discharge.
"DRAINAGE FACILITY." Any component of the drainage system.
"EXCESS STORMWATER RUNOFF." That portion of stormwater which exceeds the safe storm drainage capacity of storm sewers or natural drainage channels serving a specific watershed.
"IMPERVIOUS AREAS." The horizontal–projected plain area of roof and paved areas of all permanently constructed roofs of houses, garages, mobile homes, businesses, industries, paved driveways, patios and parking lots, but does not include no-permanent structures such as temporary buildings and tents. Also excluded are impervious areas of stored materials and equipment, swimming pools, ponds and lakes, and storm water retention and detention basins. Gravel or rock roads and gravel or rock parking areas are not considered as impervious areas.
"LAND DISTURBANCE ACTIVITY." Any change that may result in soil erosion from wind, water and/or ice and the movement of sediments into or upon waters, lands, or right-of-way within the city, including, but not limited to, building demolition, clearing and grubbing, grading, excavating, transporting and filling of land. It can also include unintentional acts such as natural weathering and intentional acts such as vandalism. It does NOT include minor land disturbances activities such as underground utility repairs, replacement of services, gardens, and maintenance work. Nor does it include installation of fence, signs, utility poles or posts. Emergency work to protect life, limb, or property and emergency repairs are not included in "LAND DISTURBANCE ACTIVITIES".
"LAND DISTURBANCE PERMIT." A permit is required by this chapter for land disturbance activities.
"PROTECTED CHANNEL." A channel which receives stormwater discharge and which is paved, rip-rapped, or otherwise improved by addition of man-made materials so as to reduce the potential for erosion.
"SAFE STORM DRAINAGE CAPACITY." The quantity of stormwater runoff that can be transported by a channel or conduit without having the water surface rise above the top of the channel or conduit.
"STORMWATER CHANNEL." A natural or man-made open watercourse with definite bed and banks which periodically or continuously contains moving water, or which forms a connecting link between two bodies of water.
"STORMWATER RUNOFF." Water that results from precipitation which is not absorbed by the soil or vegetation or evaporated and which flows over the ground surface or is collected in channels or conduits.
"STORMWATER RUNOFF RELEASE RATE." The rate at which stormwater runoff is released from dominant to servient land.
"TWENTY-FIVE-YEAR, 24-HOUR FREQUENCY RAINFALL." A precipitation event of 24-hours’ duration, having a 4% chance of occurring in any one year.
(Ord. 432, passed 5-16-90; Am. Ord. B2006-8, passed 5-23-06; Am. Ord. B2011-19, passed 9-27-11)