2005/08/10 Council Agenda Packet

Exhibit 1 1 3 A gain of approximately 1,201 IVA acre-points was projected in the Salmon Overlay for a moderately conservative restoration scenario (mean of minimum and maximum effort). Additional value could be added by increasing channelization and connectivity, maintaining and enhancing riparian vegetation. If only 24 acres of the 26-acre site were restored and the calculated score of 57 IVA points per acre achieved, the restoration would yield approximately 1,370 IVA acre-points. (5). Mechanisms to insure implementation and to measure effectiveness: If the project is constructed, it will include a monitoring and management program similar to those described above. c. Port of Everett - Union Slough Dike Breach Expansion North Spencer Island (1). Project Description: In February 2001, the Port of Everett breached a dike along Union Slough on North Spencer Island to create an approximately 24- acre tidal area. The objective was to create mudflat and saltmarsh estuarine habitat to replace the habitat and ecological functions lost as part of Port improvements at the South Terminal. The South Terminal properties that were impacted scored approximately 2.7 to 4.7 IVA points per acre. By November 2002, monitoring showed that the Union Slough site was providing approximately 58.5 IVA points per acre, a large gain compared to the impacted areas. The score could increase in the future if marsh develops over more than 25% of the site, if riparian buffer is established, and as the site accumulates more large woody debris along its shoreline. The Port of Everett is planning a 4.6 acre expansion of their Union Slough mitigation site. 3.49 acres of the expansion will be mitigation for dredging and improvements at the 12th Street Marina. Expansion will be accomplished by building an internal dike north along the existing site public access area, east along the existing Biringer Farm access road, and south along the site property line to join into the existing dike. Material within this diked perimeter will be excavated and contoured to form a channel system. The northern dike of the existing site will then be breached and the existing northeast channel connected into the new portion of the site. To resist erosion forces during sustained south winds during high tides, south-facing portions of the new dike will be faced with rounded river gravel/cobble. Over time, marsh vegetation is expected to colonize these areas to provide dike face stability. (2) Schedule: Construction is expected to occur in the fall/winter of 2004/2005, subject to obtaining the necessary permits. (3) Costs/Funding Sources: This project is funded by the Port of Everett as mitigation for other projects, including the 12th St. Marina project. i 2 5 Section 3 General Goals, Objectives,Policies and Regulations Page 3-55