Surface-level maintenance is necessary both for ecological performance and for aesthetic value. Remove trash, sediment, and debris from stormwater facilities and tree trenches; this routine maintenance should be completed frequently, anywhere between weekly and quarterly. Partner with a community group or Business Improvement District where possible.
Erosion repair and control, as well as structure or pavement inspection (and potentially repair), should occur at least once annually by a trained crew.
For permeable pavement systems, street sweeping and vactoring should be completed frequently, as often as weekly, to ensure that pores remain open for water to drain through. Small stones and aggregate between pavers should be replaced periodically, as small materials will gradually be removed through the course of normal wear.
Monitor bioretention facilities according to their design goals. Use water sampling monitoring or infiltration testing to ensure the facility drains as intended. Monitor the rate of sediment accumulation and adjust the frequency of cleanings and maintenance as necessary.
Identify opportunities to work with non-profit and neighborhood organizations to provide additional landscaping and cleaning, especially at high-profile locations such as a commercial district. Consider the partner organization’s capacity when outlining a scope of work or maintenance contract.
Watering and irrigation are essential during the establishment period of new bioretention facilities, and should be done as often as daily at first. Piped irrigation systems or watering bags can reduce the amount of labor required to nurture new plantings.
Weed removal is critical to facility health and performance, especially in the period after installation. Crews or maintenance partners may need to care for new facilities weekly.
Mulch and soil should be inspected periodically for loss, compaction, or other issues that can affect vegetation health.
Maintenance crews or trained partners and stewards should complete pruning or trimming typically at least once per month as part of routine superficial inspection and care. Ensure partners receive proper education so plants are not over-pruned. Perennials should also be trimmed back each winter in cold-weather climates.
At the end of a facility’s design life, major maintenance or full reconstruction may be necessary to replace feature components such as soil, mulch, or vegetation.
More involved subsurface cleaning and maintenance may be completed either semi-annually or annually, depending on what types of systems are installed, and what intensity of use is placed on the system by regional climate and performance need.
Typical subsurface tasks may include vacuum cleaning and jet-rodding of cleanouts and sewer pipes to ensure proper drainage rates and volumes.
While the expected lifespan of green infrastructure varies by cell type, construction materials, climate, and the amount of stormwater managed and treated by the facility, plan for cyclical replacement of soil and media, and possible need for full reconstruction of stormwater facilities. These infrequent maintenance tasks may be needed after 10 to 20 years of performance, though design life varies widely and should be broadly planned for during the design process. Regular maintenance can extend the life cycle of green infrastructure assets.