Hydro Nation: annual report 2022

Promoting growth and innovation in the water sector

Scottish Water's route to net-zero

Greenhouse Gas Emissions Halved as Net Zero Routemap Update Published

Exactly half of the greenhouse gas emissions associated with the delivery of Scotland's water and wastewater services have been cut. The second annual update of Scottish Water's Net Zero Emissions Routemap has been published and highlights the progress made.

Last year saw a reduction of 18,000 tonnes in operational greenhouse gas emissions – taking the total yearly figure to 231,000 CO₂e. This was achieved though delivering a mixture of energy efficiency, generating renewable energy, transforming the fleet and planting more than 200,000 trees. In 2006/07, the baseline year for measurement, the figure was 462,000 CO₂e. These are all emissions which stem from the processes of managing and delivering Scotland's daily water needs and wastewater treatment.

Scottish Water made progress across all areas of the routemap, delivering actions to eliminate, reduce or capture emissions.

Highlights include:

• increasing the pace of energy efficiency delivery through improving control of wastewater treatment as part of the long term 20% efficiency target
• upping the rate of renewables delivery, adopting new battery technology to maximise the benefits of solar power, and concluding studies that enable Scottish Water to extend its renewable self-generation target to 120GWh by the end of the decade
• innovative partnerships to trial co-digestion of distillery material and wastewater sludge to maximise biogas production
• piloting low carbon concrete, alternative materials and delivery approaches with capital investment partners to support development of a pathway to net zero capital investment
• commencing transition of 800 small van fleet to electric vehicles
• planting over 240,000 trees to begin the carbon capture journey

UNESCO Ecohydrology Demonstration

The Eddleston Water project, which is the Scottish Government's long-running empirical study on the effectiveness of natural flood management measures, has been designated a UNESCO Ecohydrology Demonstration site. As such it becomes the first UK study to be recognised and will now be included in the UNESCO Intergovernmental Hydrological Programme, part of the UN system dedicated to water research and management; enabling the creation of policies to achieve water quality improvement, biodiversity enhancement and sustainable development.

Managed by Tweed Forum and funded by Scottish Government, EU Interreg and SEPA, the project is delivered in collaboration with University of Dundee's UNESCO Centre for Water Law, Policy & Science, British Geological Services, local farmers and the surrounding community. Initiated in 2012, the project is collecting evidence of the costs and benefits of using Natural Flood Management techniques to reduce flood risk through the restoration of natural processes that slow water flow and increase the amount of water stored in the landscape. This helps reduce the risk of flooding to communities downstream and provides adaptation to climate change, while simultaneously improving the biodiversity of the river.

Measures implemented across the 69km² catchment include the creation of 38 new ponds to catch surface water flow and the remeandering of 3.5km of once-straightened river channels. Over a hundred log structures have been placed in streams in the upper catchment, slowing excess water by directing it onto land either side of the river channel. Over 330,000 native trees have also been planted across the catchment which provide a positive impact for ecology and sequestering carbon, and also aid water infiltration in upstream areas where floods are generated, further helping slow overland water flows.

Results to date have shown reduced peak water levels downstream during heavy rain as well as a delay of up to 7 hours in the timing of river peaks, which gives people more time to prepare and take action. There has also been a rise in fish numbers due to increasing the channel length through re-meandering, and a recovery in the diversity and numbers of aquatic invertebrates in response to the range of new habitats created within the re-meandered channels. Other species including Kingfishers, Dippers, Lampreys and Otters will also benefit from improvements to these river habitats.