The WetlandMod® leverages the same horizontal flow advantages as the Modular Wetlands® System Linear to combine screening, separation, and biofiltration treatment stages. The compact modular design is a Low Impact Development (LID) solution which is functionally equivalent to bioretention, with up to a 50% smaller footprint and the ability to reduce and control water volume in a more efficient way.


  • Horizontal flow biofiltration
  • Volume reduction & control
  • Pretreatment chamber
  • Reduced clogging
  • 50% smaller footprint
  • No depressed planter area
  • Low maintenance costs

Approvals & Performance

Washington Ecology Functional Equivalency

The Washington State Department of Ecology (Ecology) finds the Bio Clean WetlandMod system is functionally equivalent to a bioretention facility when used for treating stormwater. The media specifications for the WetlandMod system must adhere to the design guidelines for bioretention areas.

The WetlandMod must use an Ecology approved bioretention soil mix.

Operational Comparison

Downward Flow Bioretention vs. The WetlandMod

Bioretention systems have an inherent flaw — the force of gravity. As stormwater runoff carries pollutants into the system, including sediments and hydrocarbons, they are deposited on top of the bioretention media where it accumulates and quickly clogs the filter media. It has been documented that sediment accumulation from just a few storm events can completely clog a bioretention system. This leads to drastically reduced infiltration rates, expensive maintenance burdens, and safety issues associated with standing water, depressed landscaping, and vector control.

Downward Flow Flaws

Horizontal Flow Advantages

  • Downward flow systems filter water in a single vertical direction, forcing material to build up on the top.
  • As sediment rapidly builds up on the media bed, flow is impeded and the bioretention system quickly clogs or fails.
  • Sediment, trash and debris entering the WetlandMod accumulate adjacent to vertical media surface reducing clogging.
  • The vertical ponding area (void area) maximizes sedimentation and minimizes clogging issues associated with downward flow bioretention.


Bioretention Mix

The WetlandMod is designed to utilize any type of bioretention mix regardless of your regional standards and regulations. From Washington state to Florida, the WetlandMod can address your local requirements and specifications, including a 5-Inch Per Hour sand compost mix found in most Low Impact Development (LID) manuals.