What is a Drainage and Wastewater Management Plan (DWMP)?

Our DWMPs are long term plans that outline how we plan to approach and manage sewerage and wastewater over the next 25 years. They provide us with the opportunity to understand the impact on our network from things such as:

Population growth - new housing developments and increased occupancy of exisiting homes

Climate change - more volatile weather, severe rainfall events, longer dry periods

Urban creep - paving over urban areas such as parks and gardens, removed natural soakways for rainwater run off

We know that how we respond to these issues will have a huge impact on our region and communities. The decisions we make will impact on our customers and the environment that we live and work in for many years, so it’s important we get those decisions right.

Improvements to your wastewater network

Our Drainage and Wastewater Management Plan covers the improvements we’re making to our wastewater network up to 2050. We’re determined to be a service you can rely on to protect the environment, handle wastewater responsibly and plan for future expansion.

We know there’s a lot to do, and we’re promising that by 2050 we will have achieved:

surface water removed
of storage added
sewers upgraded
treatment works upgraded

To do this, we’ve split the region into 22 catchments. Each area has a specific plan of improvements and upgrades that we’ll be working on. Some of the major projects include:

Picture of a storm tank
Some of the things we're doing

Increasing storm storage

At times of high rainfall the water flow into our treatment works currently hits levels well above capacity. So, by increasing storm storage capacity, we plan to reduce the number of times wastewater is discharged straight into water courses (rivers, sea etc) through storm overflows – down to 10 spills per year in any one location by 2050.

More about storm overflows
Picture of works to separate sewers
Some of the things we're doing

Separating combined sewers

To further help control the amount of wastewater ending up at our treatment works, we’re separating surface water (rainwater) from the foul sewerage. The surface water is released into watercourses with minimal treatment, freeing up the treatment works to more efficiently treat foul sewage from homes and businesses.
Picture of a storm. A wave can be seen crashing over a railway track
Some of the things we're doing

Upgrading our sites

In the next few years, we’ll be upgrading, improving, and even relocating some sites to protect them from rising sea levels, coastal erosion, and demand changes.
A few people standing and looking at a river
Some of the things we're doing

Proactive interventions

We’re collaborating with landowners on a wide range of land management solutions which will help keep our rivers healthy.
Nature-based solutions
Picture of ants farming
Some of the things we're doing

Creating green spaces for wildlife

We’re making our sites more wildlife friendly in our ground management techniques and protecting the wildlife like bats, birds and unique plants and insects that already live there.

Our plan to 2050

Our first DWMP was published on 31 May 2023 and was developed in line with the industry framework.

You can read our plan below, as well as our customer and technical summaries.

Our Plan to 2050

Technical Appendices

Data Tables

Strategic catchments

Each wastewater treatment works in our region has an area that it serves – we like to call these catchments. Currently, we have c. 653 of these! To enable us to focus our planning we have split these into 22 larger catchments – this means we can manage our region as an entire system rather than looking at smaller challenges isolated to individual treatment works.

You can find out more about our plans for each of these areas using the map opposite - please click on the orange dots to read the plan for each catchment or the full list can be found in the section below. 

Strategic catchments

Our plan for healthy rivers and seas

As part of our DWMP, we are running a programme of work called WaterFit which is focussing on improving the river and sea quality in the region.

Our plan for healthy rivers and seas image