Lavant wetlands to reduce storm overflows
Our Lavant wetland has treated 134 storm overflows that would have previously gone out into the environment of West Sussex as settled storm releases.
The problem at Lavant
When the river Lavant fills up in the winter months, it adds to the high groundwater issues in the local area caused by heavy or prolonged rainfall.
This groundwater reaches high pressures and forces its way into the sewer network through joints in pipework. When the system fills up, tankers and over pumping are used to remove the excess water and either take it to our treatment works or divert it into nearby waterways. When this isn‘t enough, storm overflows are automatically activated to prevent the water backing up into homes and streets.
Building a constructed wetland
We’ve created a wetland at our Lavant Wastewater Treatment Works to hold and treat excess water. This will reduce storm overflows and protect the water quality of the River Lavant.
Find out more about how wetlands work.
The result
Reduced storm overflows to the River Lavant
As of July 2024, the wetland has treated 134 storm overflow releases that would have previously gone out into the environment of West Sussex as settled storm releases. This means the stormwater has been through an extra level of treatment before being released.
Biodiversity and carbon offsetting
Wetlands encourage new wildlife into the area, including important insects that provide pollination and pest control like bees, butterflies and dragonflies. They also provide carbon sink benefits, reducing the environmental impact of emissions and improving air quality and health.
Doing better for our customers
Tankers and over pumping are used to take excess water out of the system and direct it into nearby waterways. The wetland is a great alternative to this, resulting in less disruption for residents and less pollution to nearby waterways.
Future work
We're working with Defra and the Environment Agency on our plans to construct up to three more wetlands before the end of 2025 to help reduce storm overflow releases across the south.
Find out more about how our Clean Rivers and Seas Task Force are reducing storm overflows across our region.