11102 EVERGREEN WAY 2018-01-01 MF Import

The following note ahould be added on the page with the biofiltratior. swale cross-sectional details: NOTE: the specified biofiltration seed mix is not a standard mix and will need to be specially ordered. All�w 3-4 weeks for delivery of the mix. If problems are encountered in obtaining a mix meetinq the City�s specifications, please contact Jane Zimmerman, City of Everett Public Works, at 259-8800. Standards for vegetated swale construction have changed recently and are not yet included in the standards manual. , . The paragraphs qiven in the attached sheet entitled "Construction of Vegetated Swales" muet be included on the plans. The swale seed and plant list from paqe IV-17 of the City's standards must also be included on the plans. A copy of tlie list is attached. The list of additional vegetation for biofiltration swales was written for a one foot wide swale. Given that the swales on this site are designed to be wider than one foot, the specification for each vegetation type must be changed from "25 clumps per lineal foot of ewale" to "25 clumps per s�cuare foot of swale". The actual contours for the swale and how they relate to the surrounding topography must be shown. Where a swale is located adjacent to a building, a minimum of ten feet of essentially flat ground should be provided between the building and the top of the swale. The swale construction notes and swale planting/seeding requirements must be shown on both the landscaping plan and the storm drainage plan, as well as the attached detail showinq the cross-section of the biofiltration/grass swale. The entire associated side slope of the swale, from the bottom of the swale to the top of the adjacent bank, must have a maximum slope of 3: 1 unless rockeries or retaining walls are used. Rockeries or retaining walls meeting the distances in the attached detail may be used to provide the vertical drop necessary for the slope of the swale to have a maximum slope of 3 : 1. The entire associated side slope of the swale, from the bottom of the swale to the top of the adjacent bank, must have a maximum slope of 3 :1 unless rockeries or retaining i walls are used. Rockeries or retaining walls may be used to provide the vertical drop necessary to meet the swale side slope requirements, but the minimum distances shown in the attached d�atail must be met. In addition, a minimum of 4 horizontal feet is required for rockeries under 7 vertical feet that are constructed per City standards.