7702 RAINIER DR 2022-04-05 - Laserfiche WebLink

. Wetlands in western Washington often contain necessary wildlife habitat resources such as food, water, thermal cover, and hiding cover in close proximity. The subject wetland and associated buffer provide protected habitat, which becomes increasingly important as areas become further populated with humans and habitat areas become fragmented. The subject wetland provides a low level of habitat for wildlife species as evidenced by Habitat Function score on the Wetland Rating Form for Western Washington of 14. Habitat functions in this wetland are limited by the proximity to roads and development (both residential and commercial) as well as the presence of invasive species. However, even with the adjacent development and presence of invasive vegetation, the subject wetland provides habitat for wildlife. During our site visit an American Crow (Corvus brachyrhynchos), black-capped chickadee (Poecile atricapillus), and American Robin (Turdus migratorius) were noted in the subject wetland and buffer. The dense vegetation within the wetlands and associated buffers on this site serves to intercept rain fall before it strikes the soil, thereby reducing erosion and improving water quality. The presence of adsorbent soils and the biological action of the wetland vegetation, serve to remove sediment and pollutants from the water. These materials are bound in the soil and plant material providing increased water quality to downstream systems. All assessed functions in this wetland are limited by prevalence of non-native and invasive vegetation. BUFFER ENHANCEMENT Because the existing wetland and stream buffer is vegetated with invasive species, the applicant is proposing to enhance the entire on-site buffer as required by EMC 37.110(A)(6) and EMC 37.170(C). Buffer enhancement will consist of removing invasive species and planting native trees and shrubs. As part of the buffer enhancement, the applicant is proposing to remove a portion of an existing, unneeded sewer line that currently runs through this buffer. Removal of this feature will be done concurrently with the removal of invasive species and the disturbed area will be seeded to the grass seed mixture recommended in this plan and restored with native trees and shrubs as part of the buffer enhancement. Buffer enhancement will consist of removing invasive species and planting 60 percent of the mitigation area with native trees and 40 percent of the mitigation area with native shrubs. All proposed species are native to the Puget Sound region and have been selected for their benefits to wildlife and their proven success on past mitigation projects. The following native trees and shrubs will be installed within the wetland and buffer enhancement areas. Acre Environmental Consulting, LLC October 29,2015 CAS& Buffer Mitigation Plan for—Kymera Inc.-7702 Rainier Drive Everett,WA Page 8