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Our DWMP headlines

An illustration showing different aspects of the Drainage and Wastewater Management Plan.

We’re proud of our first DWMP and encouraged by the level of positive feedback we’ve received. By engaging and working collaboratively with our customers and stakeholders, we’ve deepened our shared understanding and developed new ways to approach drainage and wastewater management across our region. 

Here are the headlines from our first DWMP.

Over the next 25 years, our DWMP will:

  • Invest £31.9 billion, an increase of c.£8 billion from our draft plan
  • Improve to no more than 10 storm overflow discharges per outfall, per year on average, into the environment
  • Protect 187,000 properties from the risk of flooding in heavy storms
  • Upgrade 82 sewage treatment works to cope with population growth*
  • Manage rainwater falling on over 7,500 hectares of land across our region with sustainable drainage solutions (SuDS)

Healthy rivers

  • We're increasing storm overflows investment by £7.0 billion to £10.9 billion to respond to changes in regulatory targets
  • We’re delivering Defra's Storm Overflows Discharge Reduction Plan targets at a faster pace. By 2030, we're committed to delivering:
    • 50% reduction in duration of storm overflow discharges
    • 80% reduction in the total annual duration of storm overflow discharges in sensitive catchments 


  • We're increasing the protection of 207 sewage treatment works from river flooding


  • We're increasing our investment in protecting properties from flooding by £1.1 billion to £19.8 billion. A higher proportion will be invested later in the plan period to support faster-paced storm overflow discharge reduction delivery
  • We're also reducing flood risk through our long-term sustainable partnerships co-delivering nature-based solutions

Evidencing best value

  • c.£6 per month customer bill increase
    • Our DWMP has been carefully developed to make sure our customer bills remain affordable**. It will require some investment from other sources
  • Two thirds of the cost
    • We compared the costs of traditional solutions to green solutions for a trial catchment in North East London and green was cheaper than grey
  • Preparing for different futures
    • We're building flexibility into our DWMP for potential different futures, through testing nine alternative pathways

Partnership opportunities and working

  • Project development with key partners to promote co-funding, planning and delivery, will be in place by the end of 2023 for some schemes
  • Through our collaborative working over 270 partnership opportunities were identified and developed***
  • Over 40% of these partnership opportunities are mature enough to be delivered in the first five years  of our DWMP


In co-creating our shared plan we:

  • Facilitated over 1,000 hours of interactive stakeholder engagement activities
  • Gained input from around 2,000 customers and stakeholders at a national, regional and local level
  • Received around 1,400 responses to the consultation on our draft plan


* Including a potential new sewage treatment works in the South East London area.

** Calculation based on the indicative customer bill impact (pounds per year per household), averaged across our region.

*** Including additional projects identified post publication of our draft plan and a number evolving from AMP 7.


How you can help

There are lots of things everyone can do to protect our drainage and the wastewater services. These include getting involved in our DWMP work, as well as carrying out these simple steps:

Bin it, don't block it

Don't flush anything other than the three Ps (pee, poo and paper) down your toilet. Never pour oil, grease and fat down the sink.

Misconnected pipes

Waste pipes plumbed into surface water drains can allow untreated wastewater to pollute rivers and streams.

Protect green spaces

Avoid choosing materials such as flagstones and tarmac for your home improvements, as these stop rainwater from naturally draining away.