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development desiqn storm is the 5 year storm. Detention <br />storage and orifice calculations mu�t be redone. The change <br />in release from the detention vault will allow the upper <br />swale to be downsized if the applicant wishes to do so. <br />PLAN REVIEW COMMENTS <br />vevetated awales: <br />The swale seed and plant list from page IV-17 of the City's <br />standards must also be included on the plans. A copy of the <br />list is attached. The list of additional vegetation for <br />`/ biofiltration swales was written for a one foot wide swale. <br />Given that the swales on this site are designed to be wider <br />than one foot, the specification for each vegetation type <br />must be changed from "25 clumps per lineal foot of swale" to <br />"25 clumps per sauare foot of swale". <br />The following note should be added on the page with the <br />biofiltration swale cross-sectional details: <br />NOTE: the specified biofiltration seed mix is not a <br />atandard mix and will need to be specially ordered. Allow <br />3-4 weeks for delivery of the mix. If problems are <br />encountered in obtaining a mix meeting the City's <br />specifications, please contact Jane Zimmerman, City of <br />Everett Public Works, at 259-8800. <br />Reccmmended methods for constructing vegetated swales have <br />changed recently. The paragraphs given in the attached <br />sheet entitled "Construction of Vegetated Swales" should be <br />iricluded on the pl3ns. <br />The swale construction notes and �wale plantfng/seeding <br />requirements must be shown un both the landscaping plan and <br />the storm drainage plan. <br />The attached detail showing the cross-section of the <br />biofiltration/grass swale should also be included on the <br />storm drainaga plans and the landscape plans. The detail <br />should help clarify swale construction. <br />The swales must be somewhat accessible for maintenance. A <br />gate in the fence along the east sid� of the upper Gwale <br />would be appropriate. <br />Given the width of the swales, some type of level spreader <br />should be placed at regular intervals along the lenqth of <br />each swale to try and prevent water from creatinq a low-flow <br />channel in the swale. A successful spreader in the pa�t has <br />been a 4 by 6 or e board (timber?) imbedded in the bottom of <br />the sw31e (long dimension downwards) and into the banks <br />(about. 2 feet). The timber must he set absolutely level at <br />