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:
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:
New storage tanks in Lyme Regis
Climate change is bringing periods of heavier rainfall. There are storm tanks to hold this water until it can be treated, but the intensity of the rain means they sometimes run out of capacity. To help this we’re looking into building new storm tanks in Lyme Regis, which would store additional wastewater at times of heavy flow.
Combined sewers
Combined sewers carry both foul sewage from homes and businesses and rainwater from roofs, paved areas and in some areas, run off from roads to the treatment works. Rainwater itself doesn’t need treatment before being released back into rivers, but where it enters a combined sewer network it uses valuable capacity and adds pressure to our pumps and storm tanks.
The best way to reduce this pressure is to separate foul and surface water flows. By building one sewer for foul sewage and another for rainwater, we can keep clean water out of the treatment process and release it safely back into rivers after passing through an oil interceptor. Customers can also play a big part by keeping rainwater out of combined sewers, for example through soakaways or other drainage solutions. Checking how your roof and driveway runoff is connected can make a difference. If none of your surface water drains to the public sewer, you may qualify for a lower bill and help ease pressure on the system during wet weather.
Upgrading our sites
Creating green spaces for wildlife
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 by looking at the documents 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.
