Over the last 15 years the water sector has been developing tools for different aspects of its carbon footprint. Through UKWIR the Carbon Accounting Workbook provides a consistent approach for annual operational emissions. Also focused on operational emissions, the Water UK Net Zero routemap programme will culminate in the provision tools for estimating carbon reductions of different options over a given period of time, and the cost per tonne of CO2 avoided.

Now, growing attention is being paid to the embodied carbon of capital schemes and the sector’s supply chain. Already, various tools are available for estimating capital carbon emissions for new assets, (some of which include operational carbon) and with developments such as PAS2080 they are becoming more standardised. But uptake has been variable across the sector.

Two interconnected risks remain. Firstly, that embodied / capital carbon continues to receive less attention than operational emissions and that capital and operational carbon are not assessed in the round – contrary to totex thinking. Secondly, that the sector lags behind regulator and other stakeholder expectations on measuring capital carbon and building it into decision making and reporting

The organisations in the water sector of UK and the island of Ireland require common GHG estimation and reporting tools that can be used for annual accounting (FY 2023-24) and to report against the Ofwat Operational Greenhouse Gas emissions common Performance Commitment during AMP8 (2025-30).

Each year, companies within the UK water industry are required to report on their Greenhouse Gas (GHG) emissions to the industry Regulator. Companies also report on other aspects of their emissions to comply with other legalisation and regulations, such the Streamline Energy and Carbon Reporting (SECR) and climate related disclosures to keep stakeholders informed on emissions and transition plans. The emissions data also contributes to the net zero work that the sector is undertaking and progress of individual company emissions reduction commitments, pledges and targets.

UKWIR has developed a standardised workbook for estimating operational GHG emissions, the Carbon Accounting Workbook (CAW), to bring consistency and accuracy to the emissions estimation methodology used across the industry.  The workbook has been in place for 16 versions (up to 2022) and is updated annually to reflect latest UK Government emissions factors, evolving best practice and recognised international Standards for greenhouse gas emissions accounting and to incorporate changes in industry practices as well as outputs from relevant water sector research projects. This GHG estimation and reporting tools for 2024 project

This GHG estimation and reporting tools for 2024 project in addition to providing an updated CAW v18 to be used for annual accounting (FY 2023-24) will develop a parallel but separate calculation tool to be used to enable Water companies’ reporting to Ofwat against the AMP8 common Performance Commitment for Operational Greenhouse Gas emissions. This is a new performance commitment and therefore does not yet have a finalised scope or agreed calculation but will need a common methodology and supporting tool to ensure undemanding and consistent reporting is possible.

To avoid inconsistent greenhouse gas emissions reporting we need a common method and accounting system. This is achieved through the carbon accounting workbook (CAW).

The CAW requires annual updating - at the very least to incorporate revised emissions factors issued by BEIS. Previous updates have also included broadening the scope of items that are quantified, and improving functionality.