Green Infrastructure for water

We have developed a model for mapping locations in the Irwell River catchment area where there is both a need and an opportunity for installing trees and other green infrastructure (GI) to help prevent and reduce water pollution.

This project is developed in partnership with The Environment Agency and United Utilities, and part funded by the EU Value+ fund.

Why Green Infrastructure for water?

Managing the risk of flooding to householders is a major challenge, with substantial cost implications for the UK, and one that is expected to increase in the future with climate change.

Poor water quality is a further challenge, with the EU Water Framework Directive requiring that all water bodies be brought to ‘Good’ ecological and chemical status.

Urban woodlands and the integration of trees and other GI with sustainable drainage solutions are being increasingly recognised as having important benefits in improving the condition of the water environment.

Irwell Catchment Pilot project

The aim of this project is to develop a systematic and strategic model to help identify where, in a predominantly urban environment, there is the greatest potential for GI to bring about improvements to the water environment, and precisely which GI solutions should be used.

Using GIS modelling

We have constructed a GIS model, comprising individual ‘layers’ of different landscape features, each representing a potential pathway for pollutants or water, and each offering the opportunity for GI interventions.

We have also produced a ‘final opportunity targeting map’, which highlights locations across the catchment where there is the greatest number of opportunities for GI to have a beneficial impact.

We can then utilise the GIS mapping functionality to assess the detailed range of opportunities present in any given location.

This model has already been used to build a portfolio of new GI projects, and is now being developed further and extended to include the upper and lower Mersey catchments.