All commercial buildings have a responsibility to ensure that water runoff from their buildings and parking lots is controlled and managed.
These regulations have been in place for some time, but the Metro Nashville Stormwater Division is turning attention toward a proactive approach to enforcement of compliance measures. There are a few simple steps business managers and facility managers can take to make sure compliance is continued and prepare for their annual inspection.
What you need to know about bio-retention space and why it’s important to your facility For facility managers:
(from “Nashville.gov - Stormwater - Green Infrastructure Practices - Bio-retention.”)
Routine and Non‐Routine Maintenance Tasks Maintenance of bio-retention areas should be integrated into routine landscape maintenance tasks. If landscaping contractors will be expected to perform maintenance, their contracts should contain specifics on unique bio-retention landscaping needs, such as maintaining elevation differences needed for ponding water, proper mulching, sediment/trash removal, and limited use of fertilizers and pesticides.
A customized maintenance schedule must be prepared for each bio-retention facility. Tasks will differ depending on the scale of bio-retention, the landscaping template chosen, and the type of surface cover.
The most common non-routine maintenance problem involves standing water. If water remains on the surface for more than 48 hours after a storm, adjustments to the grading may be needed or under-drain repairs may be needed.
Suggested Annual Maintenance Activities for Bio-retention
- Mowing of grass filter strips and bio-retention turf cover at least 4 times a year
- Remove invasive plants using recommended control methods as needed
- Stabilize the contributing drainage area to prevent erosion as needed
- Spring inspection and cleanup annually
- Supplement mulch to maintain a 3-inch layer annually
- Prune trees and shrubs annually remove sediment in pre‐treatment cells and inflow points once every 2 to 3 years
- Spot weeding, erosion repair, trash removal, and mulch raking twice during the growing season
- Add reinforcement planting to maintain desired vegetation density as needed
- Replace the mulch layer every 3 years