Ordinance 3676-19 - Laserfiche WebLink

3. "Normal rainfall" refers to rainfall that is at or above the mean of the accumulated rainfall record, based upon the water year,for the city as recorded at the Seattle Tacoma International Airport, or other local rainfall recording station recognized by the city. 1. "Perennial stream" refers to those stream segments that do not go dry at any time during a year of normal rainfall. 5. "Riparian corridor" m ans a perennial, intermittent, ephemeral stream or swale including its channel bottom, lower and upper banks, and area beyond the top of the upper bank which influences and upland ecosystems and docs not necessarily include the entire floodplain of a stream. 6. "Stream" refers to those areas, excluding erosion caused by the inappropriate discharge or rerouting of storm or surface water, where surface waters flow with sufficient volume,velocity, duration, and/or frequency to scour away leaf litter and other vegetative matter and/or scour away or pre=vent the-growth of vegetation such that clear evidence of the passage of flow is present on the land and remains even in the absence of such flow. Sod lined or other heavily vegetated swales and wetted areas, which remain lined with I of litter or other vegetative matter,do not meet the criteria of a canals, are not considered streams unless they are used to convey water which flowed in a naturally defined channel prior to the creation of the artificial watercourse or are used by salmonid fish. C. Periodically inundated wetlands that fall within the str m classifications are also subject to the wetland regulations of this chapter. (Ord. 2909 06§ 16, 2006} 19.37.140-1-7-0 Standard stream and lake buffer requirements. A. Standard Buffer Width. It is the goal of this chapter to preserve streams and their buffers in a natural condition to the maximum extent possible. 1. Buffers shall be measured from the top of the upper bank or, if that cannot be determined,from the ordinary high water mark as surveyed in the field. In braided channels and alluvial fans, the top of the bank or ordinary high water mark shall be determined so as to include the entire stream feature. 2. The standard buffer widths required by this chapter presume the existence of a relatively intact native vegetated community including native tree cover, shrub understory and ground cover. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species,the buffer width shall be increased as required by this section. 3. Except as otherwise provided by Section 19.37.050 of this chapter,the following minimum buffers of native vegetation shall apply to streams based upon stream classification: Table 37.5:Stream Buffers Standard Buffer: U nvegetated; Standard Buffer: Sparsely Vegetated; Stream Classification Intact Native or Vegetated with (Type) Vegetation Invasive Species Type S Buffer determined Buffer determined by requirements of by requirements of city of Everett city of Everett Planning Commission Resolution 19-04 Page 49 Critical Areas March 19, 2019