9205 4TH AVE W 2025-12-03 - Laserfiche WebLink

RAIN GARDEN OPERATION AND MAINTENANCE MANUAL In a low impact development, native vegetation and soil protection areas serve as stormwater management facilities. Clearly written management plans and protection mechanism are necessary for maintaining the benefits of these areas over time. Some mechanisms for protection include dedicated tracts, conservation and utility easements, transfer to local land trusts (large areas), and homeowner association covenants. Property owner education should be part of all these strategies. Ongoing maintenance should include weeding, watering, erosion and sediment control, and replacement of dead plant material for a minimum of three years from installation in order to achieve a minimum 80 percent survival of all plantings. If during the three-year period survival of planted vegetations falls below 80 percent, additional vegetation should be installed to achieve the required survival percentage. Additionally, the likely cause of the plant mortality should be determined (often poor soils and compaction) and corrected. If it is determined that the original plant choices are not well suited to site conditions, these plants should be replaced with plant species better suited to the site. Permanent signs should be installed explaining the purpose of the area, the importance of vegetation and soils for managing stormwater, and that removal of trees or vegetation and compaction of soil is prohibited within the protected area. Permanent fencing, rock barriers, bollards or other access restriction at select locations or around the perimeter of protection areas may be required to limit encroachment.