Infiltration Systems

In simple terms, anything that allows water to pass through to the soil below is, essentially, a filtration system. Designed to enable, or enhance, the infiltration of surface water run-off into the ground, a filtration system can be used in isolation but also as part of a 3D (multiple plane) infiltration system.

In the context of SuDS design, a hierarchal approach is taken to how surface water should be managed within a development. Where infiltration systems are required to be considered in the first instance, prior to options that result in a discharge outside the development; whether this is to an adjacent river, watercourse or sewer.

Infiltration of surface water can offer the following potential benefits:

• Reduces the total volume of run-off discharged outside a development; thereby reducing the total attenuation storage that may be required, in addition to delivering interception for the contributing surfaces drained to the system.
• Replenishes local ground water, which may also help support local water course base flow.
• Maintains site soil moisture levels, supporting vegetation and planting and, in turn, attracts biodiversity.