Simple Index Approach (SIA) For SuDS Developments

When the Simple Index Approach (SIA) is requested as part of a planning condition for a new development, it is used to assess potential pollution risks from surface-water runoff and demonstrate that appropriate water-quality treatment has been provided within the proposed SUDS scheme. The SIA supports the design and justification of the proposed SUDS treatment and helps demonstrate compliance with relevant SUDS and planning requirements. Information required to complete the SIA: Site location and development proposal. Site layout showing the areas draining to the proposed SUDS solution (i.e soakaway/ attenuation). Proposed land uses within the development (e.g. residential roofs, residential/front paved areas, roads). Existing and proposed drainage arrangements. Proposed SUDS devices/treatment measures (e.g. permeable paving, bioretention systems). Ground investigation information and infiltration rates, where a soakaway solution is proposed. Discharge location and proposed discharge rate, where an attenuation solution is proposed. Outputs: Completed Simple Index Approach assessment of the proposed SUDS treatment (PDF). If a SuDS design is required, please find our list of SuDS drainage design services here. Please note: Allow 10 working days for the output to be delivered from supply of information requested above.