17 E MARINE VIEW DR 2022-02-01 - Laserfiche WebLink

MEMO: Landscape Restoration Methodology for Delta Site 12 September 2018 Page 3 SITE RESTORATION PREPARATION The purpose of this memorandum is to document the scope and methodology of the proposed landscape restoration activities. The landscape restoration plan removes post -fill, non-native soils and invasive plants within 100 feet of the wooden bulkhead retaining wall. Surface grades will be restored to approximate pre -fill conditions. Restored site areas will then be ripped to a depth of 12 inches and rocks, debris, and other man-made materials will be removed. Soil nutrient and organic matter soil tests will be completed. The remaining soils will be amended with organic compost and recommended soil amendments necessary to provide a suitable growing medium for proposed plantings. LANDSCAPE PLANTINGS Native deciduous and evergreen trees will be placed in loose drifts surrounded by native shrubs that mimic natural groves and meadows of the pre development landscape. New plantings will be selected from an indigenous plant palette suitable for riparian areas in the Puget Sound lowlands. Proposed native plants will improve the ecological function of revegetation area. Native trees will be placed 10 feet on center in loose drifts to provide a variety of sun and shade conditions conducive to riparian plant communities. Shrubs and herbaceous plants will be planted in the remaining areas at densities to create planting masses. All planted areas will be top dressed with 3 inches of wood chip mulch. The drifts of trees will also allow both a more natural, filtered view of the Snohomish River from within the site and softened views from outside of the site, including views from Pacific Highway. LANDSCAPE IRRIGATION A temporary, automatic irrigation system will provide water during the plant establishment period. It is recommended that irrigation be provided for the first two complete growing seasons to maintain plants in a vigorous growing condition and to speed establishment. The number and spacing of emission devices will be sufficient to cover the entire revegetation area. The frequency of watering will be determined by weather and precipitation patterns but it is anticipated that watering will be required between four and eight times per month during hottest and driest periods. The design -build system will be removed after two full growing seasons. LANDSCAPE MAINTENANCE Landscape maintenance for the restoration area includes watering, monthly weeding, and debris removal as necessary to promote successful plant establishment. All plantings will include a 1-year plant warranty and any dead or dying planting materials at the end of the 1-year warranty period will be replaced. The irrigation system will receive annual winterization and backflow preventer testing. 6-5