The Maintenance Advantage of High-Rate Biofiltration
Why High-Rate Biofiltration Simplifies Long-Term Maintenance
Effective stormwater management requires looking beyond initial installation costs. While many stormwater treatment systems have similar regulatory performance standards, their long-term operation and maintenance requirements can vary significantly depending on the system’s design, footprint, and technology.
This is especially true when comparing traditional bioretention with proprietary high-rate biofiltration systems such as Contech’s Filterra Bioretention System and similar systems.
Biofiltration Requires Consistent Upkeep
Whether designing traditional or proprietary biofiltration systems, each system relies on water infiltrating through a series of vegetation, mulch, media, and underdrain stone to an underdrain pipe. Over time, total suspended solids (TSS), trash, leaves, and debris can accumulate at the surface and around inflow points. If not removed, this material can reduce the infiltration rate and eventually prevent the system from draining properly.
Routine maintenance may vary slightly for different biofiltration systems; however, the overall procedure is similar. Crews will typically remove trash and sediment from inflow areas, pull invasive weeds, trim existing vegetation, check overall plant health, and replace the top mulch layer as needed. This work is typically performed with manual tools such as rakes, shovels, pruners, and soil probes.
If routine maintenance is not sustained, this could lead to more substantial corrective maintenance being needed. If a system becomes inundated or the design infiltration rate is not being met, remediation can require vacuum trucks, skid steers, dump trucks, and removal or replacement of the media layer and/or internal components. This often occurs when fine silts form a crust on the surface, limiting infiltration and causing standing water.
Traditional Bioretention Can Create Large Maintenance Areas
Traditional bioretention systems are typically designed using lower filtration rates, which means they often have larger surface areas to treat the required runoff volume.
That larger footprint directly affects maintenance costs and timing. Crews may need to maintain large, landscaped basins which may include, replacing substantial quantities of mulch, removing large sums of accumulated debris and sediment, , and repair any erosion or surface clogging across a broad area. If the system lacks effective pretreatment or receives heavy sediment loads, the basin can become inundated quickly in a centralized area and require major corrective actions over time.
For owners, this can turn a landscape feature into a costly long-term maintenance obligation.
High-Rate Systems Make Maintenance More Predictable
High-Rate Biofiltration Systems use engineered high-flow media with increased infiltration rates to treat stormwater in a compact footprint.
Because the treatment area is condensed, maintenance is faster, more standardized, and easier to plan. Instead of maintaining a large basin, crews are able to focus efforts on a smaller system area, typically housed in a precast vault.
In many cases, a single technician can service a high-rate biofiltration system like Filterra in less than an hour using basic landscaping tools and a few bags of mulch. To see this firsthand, watch this short video to see how Filterra is maintained. Routine maintenance does not typically require confined-space entry or a vacuum truck.
Lower Maintenance Risk Supports Long-Term Performance
The practical advantage of high-rate biofiltration is that it can convert maintenance from a site-wide burden into a simpler operating task. That matters for owners, municipalities, and property managers responsible for keeping systems functional after construction.
Traditional bioretention remains a valuable stormwater tool where sufficient land and maintenance resources are available. But on constrained sites, or where long-term maintenance is a priority, high-rate biofiltration offers a strong position.
By combining proven biofiltration treatment mechanisms with a smaller footprint and easier routine upkeep, high-rate biofiltration helps owners meet water quality goals while reducing the long-term maintenance challenges often associated with large traditional bioretention systems.