1600 121ST ST SE 2016-01-01 MF Import

The following note should be added on the page with the biofiltration swale cross-sectional details: NOTE: the specified biofiltration seed mix is not a standard mix and will need to be specially ordered. Allow 3-4 weeks for delivery of the mix. If problems are encountered in obtaining a mix me�ting the City�s specifications, please contact Jane 2immerman, City of Everett Public Works, at 259-8800. Standards for vegetate� swale conetruction have chanqed recently and are not yet included in the standards manual. The paraqraphs given in the attached sheet entitled �'Construction of Vegetated Swales" must be included on the plans. The swale seed and plant list from page IV-17 of the City's standards must also bc included on the plans. A copy of the liat is attached. The list of additional veqetation for biofiltration swales was written for a one foot wide swale. If 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 swale" to "25 clumps per s�cuare foot of swale". The swale construction notes and swale planting/e;eeding requirements must be shown on both the landscaping plan and the storm drainage plan, as well as the attached detail showing the cross-section of the biofiltration/grass swale. Wetponds If the applicant chooses to design the surface pond to meet wetpond standards, the followtnq review comments are typical: The wetpond�s length to width rat+_o must be a minimum of 3:1. Baffles can be used to create an effective length to width ratio qreater than 3:t. Baffles used for this purpose must extend vertically fros� the bottom of the pond to G inches above tha elevat4on at which the required wetpond volume is provided. A wooden baffle essentially constructed like a fence in the bottom of the pond has been used successfully in the past. A plan detail and information on an environmentally safe wood preservative are attached for the applicant's information. The standards also call for at lea�t one baffle across the width of the pond. This baffle must extend vertically from the bottom of the pond to the elevation at which the required wetpond volume is provided.