Policy information sourced from the Merton Sites and Policies Plan

DM F2 Sustainable urban drainage systems (SUDS) and; wastewater and water infrastructure

Link to Core Planning Strategy Policy CS 16 Flood Risk Management

Policy aim

To help reduce the overall amount of rainfall being discharged into the drainage system to reduce the borough’s susceptibility to surface water flooding and to reduce water use.

Policy

The council will require all developments to reduce water consumption, the pressures on the sewer network and the risk of flooding by:

  1. Ensuring all new developments have to consider SUDS and demonstrate sustainable approaches to the management of surface water in line with the emerging National SUDS standards.
  2. Seeking mitigating measures against the impact of flooding from all sources; and surface water run-off through the inclusion of SUDS including green roofs rainwater harvesting and other innovative technologies where appropriate.
  3. Ensuring developers demonstrate the maintenance and long-term management of SUDS through a SUDS Management Plan.
  4. Requiring developers, where feasible, to incorporate soft landscaping, appropriate planting (including trees) and permeable surfaces into all new developments including non-residential developments.
    For development proposals associated with existing homes, the council requires:
    1. The retention of soft landscaping and permeable surfaces in gardens and the reduction, or at least not the increase in, the amount of impermeable surface associated with existing homes
    2. new driveways or parking areas associated with non-residential developments and those located in gardens to be made of permeable material in line with permitted development rights
  5. Requiring any development or re-development that impacts on a heritage asset or its setting (including conservation areas) has to consider SUDS and demonstrate within a Heritage Statement, the approach taken to ensure that there is no adverse impact on the character and appearance of the asset and that there is no long term deterioration to the building’s fabric or fittings.
  6. Requiring developers, when discharging water including wastewater into the public sewer, development proposals are required to demonstrate that the local public sewerage network has adequate capacity to serve the development and existing developments. If the public sewer does not have adequate capacity, the developer should demonstrate alternative sustainable approaches to the management of water.
  7. Requiring any development proposals with adverse impact including potential water pollution will be refused by the council.
  8. The development or expansion of water supply or waste water facilities will normally be permitted, either where needed to serve existing or proposed new development, or in the interests of long term water supply and waste water management, provided that the need for such facilities outweighs any adverse land use or environmental impact.
  9. Requiring any new water supply, sewerage or waste water treatment infrastructure must be in place prior to occupation of the development. Financial contributions may be required for new developments towards the provision of, or improvements to such infrastructure.

For more information see the Merton Sites and Policies Plan