220 OLYMPIC BLVD VA OUTPATIENT CLINIC 2023-02-09

. Place irrigation systems to ensure that plants receive water where they need it. For example, do not place irrigation systems downgradient of plant's root zones on hillsides. Recommended Operational BMPs: . Add a tree bag or slow-release watering device(e.g., bucket with a perforated bottom)for watering newly installed trees when irrigation system is not present. . Water deeply, but infrequently,so that the top 6 to 12 inches of the root zone is moist. • Use soaker hoses or spot water with a shower type wand when an irrigation system is not present. Pulse water to enhance soil absorption,when feasible. Pre-moisten soil to break surface tension of dry or hydrophobic soils/mulch,followed by several more passes.With this method, each pass increases soil absorption and allows more water to infiltrate prior to runoff. . Identify trigger mechanisms for drought-stress(e.g., leaf wilt, leaf senescence,etc.)of dif- ferent species and water immediately after initial signs of stress appear. . Water during drought conditions or more often if necessary to maintain plant cover. . Adjust irrigation frequency/intensity as appropriate after plant establishment. . Annually inspect irrigation systems to ensure: <, That there are no blockages of sprayer nozzles. Sprayer nozzles are rotating as appropriate. Sprayer systems are still aligned with the plant locations and root zones. • Consult with the local water utility, Conservation District,or Cooperative Extension office to help determine optimum irrigation practices. . Do not use chemigation and fertigation in irrigation systems.This will help avoid over applic- ation of pesticides and fertilizers. 2019 Stormwater Management Manual for Western Washington Volume IV-Chapter 4-Page 536