2025/03/19 Council Agenda Packet

CITY OF EVERETT PUBLIC WORKS DEPARTMENT  SMITH ISLAND ESTUARY RESTORATION ADVANCE MITIGATION SITE: YEAR 7 MONITORING Page 4 | February 18, 2025 ASSUMPTIONS:  Site conditions are such that the hydroperiod field work can be accomplished within two site visits by two NSD staff – gage installation and gage retrieval. Approximately 10 hours for gage deployment and survey and 8 hours for retrieval site visit by two NSD staff is included, including travel.  Gages will function as intended over their month deployment; vandalism or loss of gage will require replacement and reinstallation through Additional Unanticipated Services task budget.  Site conditions are such that the salinity monitoring field work can be accomplished within one approximately 8-hour site visit, including travel, by two NSD staff.  Site conditions are such that the wetland delineation data collection field work can be accomplished within one approximately 8-hour site visit, including travel, by two NSD wetland biologists.  Survey of the WSE gages will use GPS RTK, no total station work will be required. DELIVERABLES:  Year 7 hydroperiod graph, included within Task 5, Monitoring Report  Year 7 salinity data, included within Task 5, Monitoring Report  Year 7 estuarine extent figure and associated wetland determination data (Appendix to Task 5, Monitoring Report) Task 2. Wetland Vegetation Development Per Tables 6-1 through 6-3 of the Advance Mitigation Plan, wetland vegetation development monitoring is required in Years 7 and 10 to quantitatively evaluate tidal marsh development, habitat complexity and interspersion, vegetation cover, and control of reed canarygrass, invasive species, and noxious weeds within the mitigation site. Subtask 2.1 Data Collection NSD will visit the project site in August or early September of 2025 to complete the Year 7 vegetation monitoring. NSD will assess the general condition of the site, collect photos from the photo point locations utilized in Years 1 through 6, and conduct vegetation monitoring in accordance with the Advance Mitigation Plan (ICF 2016) and consistent with the methods NSD used for Years 3 and 5 vegetation monitoring. NSD biologists will record species composition and percent cover of all identifiable species in approximately 130 vegetation sample plots (each 1 square meter in size) located along at least 13 transects, oriented north to south across the topographic gradient of the site. The location of the first sample plot on each transect is determined using a random distance between zero and 50 feet from the northern boundary of the AMS. Thereafter, sample plots are positioned at 75-foot intervals to the south. NSD will employ GPS to navigate the transects and to the location of each sample plot and will record transitions between mudflat, marsh, and tidal channel communities along each transect to support creation of the Year 7 vegetation community map. Invasive and noxious weed monitoring will occur along the surveyed vegetation transects and in the sample plots. Invasive and noxious weeds will also be qualitatively monitored by observational surveys from the ends of the transects and from the photo point locations. The aerial photo will also be utilized,