Draft London Sustainable Drainage Action Plan - Greater London ...

The Mayor believes that landlords of large commercial buildings should pay for the .... techniques can be found in a range of other documents and websites. .... different sustainable drainage options and the Benefits of SuDS Tool (BeST) is an ...
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LONDON SUSTAINABLE DRAINAGE ACTION PLAN Draft for public consultation

LONDON SUSTAINABLE DRAINAGE ACTION PLAN – draft for public consultation

COPYRIGHT Greater London Authority October 2015 Published by Greater London Authority City Hall The Queen’s Walk More London London SE1 2AA www.london.gov.uk enquiries 020 7983 4100 minicom 020 7983 4458 ISBN Photographs © Copies of this report are available from www.london.gov.uk

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LONDON SUSTAINABLE DRAINAGE ACTION PLAN – draft for public consultation

CONTENTS EXECUTIVE SUMMARY

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PART 1. WHY WE NEED & WANT MORE SUSTAINABLE DRAINAGE

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Surface Water Management in London Surface Water Management Challenges What is Sustainable Drainage? International Experience of Sustainable Drainage The Case for Sustainable Drainage in London Sustainable Drainage Vision Current Sustainable Drainage Planning and Delivery in London PART 2. THE SUSTAINABLE DRAINAGE ACTION PLAN The Sustainable Drainage Action Plan Understanding the Opportunities and Benefits of Sustainable Drainage Delivering Sustainable Drainage through New Developments via the Planning System Retrofitting Sustainable Drainage across London What Can You Do? Delivering Sustainable Drainage through Domestic and Local Neighbourhood Measures Funding Opportunities & Regulatory Incentives Monitoring APPENDIX 1: Action Plan by Year

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LONDON SUSTAINABLE DRAINAGE ACTION PLAN – draft for public consultation 4

EXECUTIVE SUMMARY

LONDON SUSTAINABLE DRAINAGE ACTION PLAN – draft for public consultation 5

London is outgrowing its drains and sewers. The combined sewer system originally built over 150 years ago by Joseph Bazalgette has served us well, but it was designed for a smaller, more permeable city. The combined challenges of London’s growing population, changing land uses and changing climate mean that if we continue to rely on our current drains and sewers, we face an increasing and potentially unacceptable risk of flooding. This Action Plan is a long-term plan intended to inspire, facilitate and co-ordinate a step-change in how we manage rainwater in the Capital. It seeks to roll back the tide of grey, impermeable surfaces and replace them with a mosaic of green ‘sustainable drainage’ systems. These add to the services provided by our existing drains and sewers, as well as bringing wider benefits to London and Londoners. This new approach recognises the value of rainwater, seeking to capture, use, delay or absorb it, rather than reject it as a waste by-product. Vision By 2040, London will manage its rainwater sustainably to reduce flood risk and improve water security, maximising the benefits for people, the environment and the economy We have all seen the impacts of heavy rainfall elsewhere in the UK and around the world. London has been fortunate to escape the worst of these storms, but it is only a matter of time before heavy rainfall seriously affects parts of London. In parallel, if London continues to seal off its permeable surfaces, effectively ‘waterproofing’ the city, even relatively light rainfall may overcome the drains and sewers. We therefore face a choice: to build further enhanced and expensive storm drains and sewers across large parts of London; or steadily increase London’s resilience by ensuring that more sustainable drainage techniques, such as greenroofs and rainwater harvesting systems, are commonly and widely used. As well as reducing and slowing down the flow of rainfall to the drainage system, many sustainable drainage techniques have a range of wider benefits for London, such as improving the water quality in our rivers and streams, providing attractive areas for people and wildlife, storing water for vegetation, irrigation, and helping keep the city cool in hot weather. Sustainable drainage measures can also have direct financial benefits by capturing and storing ra