Stormwater Quality Design Manual (May 2007) - City of Sacramento ...

Runoff Treatment Control Measure Fact SheetVegetated Filter StripStep 8 – Design irrigation systemProvide an irrigation system to maintain viability of filter strip grass.Construction Considerations• Divert runoff (other than necessary irrigation) during the period of vegetation establishment.Where runoff diversion is not possible, cover graded and seeded areas with suitable erosioncontrol materials.• Install sediment controls (e.g., staked straw wattles) around the filter strip to prevent highsediment loads from entering the filter strip during ongoing upstream construction activities.• Repair, seed, or re-plant damaged areas immediately.Long-Term MaintenanceThe local permitting agencies in the Sacramento and South Placer areas will require execution of amaintenance agreement or permit with the property owner for projects including a vegetated filter strip.Check with the local permitting agency about the timing for execution of the agreement. Such agreementswill typically include requirements such as those outlined in Table VFS-2. The property owner or his/herdesignee will be responsible for compliance. See Appendix B for additional information aboutmaintenance requirements and sample agreement language.Table VFS-2. Inspection and Maintenance Recommendations for Vegetated Filter StripsActivityMow grass to maintain a height of 2 to 4 inches (typical).Use integrated pest management (IPM) techniques tominimize use of fertilizers, pesticides and herbicides.Remove trash and debris from the filter strip.Inspect filter strip for signs of erosion, vegetationdamage/coverage, channel formation problems, debris buildup,and excessive sedimentation on the surface of the strip.Correct problems or remove debris and sediment as soon aspossible.Remove sediment in inlet areas, the channel, culverts, andoutlets whenever flow into the filter strip is retarded orblocked.Repair ruts or holes in the strip by removing vegetation,adding and tamping suitable soil, and reseeding. Replacedamaged vegetation.Inspect filter strip for obstructions (e.g., debris accumulation,invasive vegetation) and pools of standing water that canprovide mosquito-breeding habitat. Correct observedproblems as soon as possible.Reconstruct or replace the control measure when it is nolonger functioning properly.ScheduleAs requiredAs requiredAs requiredAt least twice annually. Schedule one inspection atthe end of the wet season so that summermaintenance can be scheduled to prepare filterstrip for wet season. Additional inspections afterperiods of heavy runoff are desirable.As requiredAs requiredAt least twice during the wet season after significantstorms. Additional inspections after periods ofheavy runoff are desirable.See projected lifespan in Appendix B forinformational purposes.Stormwater Quality Design Manual for the Sacramento and South Placer RegionsVFS-4 May 2007