Infiltration SuDS map

This dataset is suitable for those involved in the planning and design of sustainable drainage systems (SuDS) and for those who approve SuDS planning applications within local authorities.

The dataset gives a preliminary indication of the suitability of the ground for infiltration SuDS. These are drainage systems that allow surface water to infiltrate to the ground, such as soakaways, infiltration basins, infiltration trenches and permeable pavements. The selection and design of an appropriate system depends on the properties of the ground, in particular these four factors:

• the presence of severe constraints that must be considered prior to planning infiltration
• the drainage potential of the ground
• the potential for ground instability when water infiltrates
• the protection of groundwater quality

The BGS Infiltration SuDS map is based on 15 nationally derived subsurface property datasets, some of which are a result of direct observations, whilst others rely on modelled data.

The dataset is structured using the four factors and allows consideration of:

• subsurface permeability
• depth to groundwater
• presence of geological floodplain deposits
• presence of artificial ground
• ground stability:
  • soluble rocks
  • collapsible ground
  • compressible ground
  • running sand
  • shallow mining
  • landslides
  • shrink–swell clays
• potential for pollutant attenuation
• the Environment Agency’s source protection zones

SuDS map products

Detailed BGS infiltration SuDS map

The detailed map provides the data layers described along with a further 20 individual, bespoke data layers. These data layers provide information on the properties of the ground, which can be used to guide local SuDS planning and design.

The data can be used to determine the likely limitations present at a site and make preliminary decisions on the type of infiltration SuDS that may be appropriate. We anticipate that this map will be used by planners, developers, consultants and SuDS approval bodies.

The dataset is intended to be used at a preliminary stage and is not a replacement for a site investigation.

Summary BGS infiltration SuDS map

The summary map comprises four summary layers, providing an indication of the suitability of the ground for infiltration SuDS. The layers summarise:

• presence of severe constraints
• drainage potential of the ground
• potential for ground instability as a result of infiltration
• susceptibility of the groundwater to contamination

This map is anticipated to be of use in strategic planning and not for local assessment. It does not provide specific subsurface data or state the limitations of the subsurface with respect to infiltration.