We must deal with whatever weather happens on a daily basis, and this included the impacts of severe weather. Since 2010 we’ve put a lot of effort into improving our understanding of how climate change could affect our ability to deliver essential services to our customers. It is widely accepted that climate change is a serious issue and a major challenge to society; however, it is almost impossible to predict the extent and timing of its impact. We have nearly 7000 operating sites providing the essential water and wastewater services to 15 million customers and we don’t want to invest at these sites inappropriately or at the wrong time. This makes planning for issues extremely challenging. Following a review of the potential impacts of climate change on the business, we identified that our key issues are still broadly associated with either too much or too little water. Today's blog focuses on our response to "too much water", which includes flooding resilience and sustainable drainage systems (SuDS). Two of our current performance commitments agreed with our regulator Ofwat include increasing flooding resilience of water (WB8) and wastewater (SB7) services for customers. We’re working hard to protect our sites from flooding. We’ve assessed our water and wastewater sites for how the might be impacted by river and surface water flooding associated with a 1 in a 1000-year event. This is to help us understand how much and where flood water would be in relation to our assets. This has helped us to better define the risks at each site and to develop more detailed investment planning needs. Through a number of schemes at our wastewater sites, we have managed to cover 962,842 population equivalent so they have a flood resilience standard of a 1 in 200 year event. Our area is in one of the most densely populated and urbanised regions in the UK, which places a lot of pressure on drainage. Heavy rain can overwhelm our sewers, so whenever possible, we take advantage of opportunities to deliver more SuDS to increase our sewer capacity, encourage natural drainage and reduce and slow the flow of surface water into our network. In 2015, we launched a SuDS programme to disconnect 20 hectares of impermeable land from the combined sewer network - one hectare is roughly the size of an international rugby pitch – and we’re on track to deliver this target. Between 2020 and 2025 we’re looking to more than triple our target to 65 hectares, providing a wide range of benefits to our customers beyond that of improving asset resilience. Nine Elms is the UK’s biggest SuDS project. With our partners we’ve been installing ambitious and innovative SuDS to ease the pressure on the existing sewerage system as a result of a number of high-profile projects planned in the Nine Elms area of Vauxhall, South London. Instead of running into the sewer network, the rainwater which falls on the area between Vauxhall and Battersea Power Station will be channelled into large underground pipes which will then be discharged into the River Thames. This big engineering project will be complemented by a variety of eco-friendly innovations in the new housing developments, including green roofs, ditches containing filtering vegetation, and streets with rainwater gardens. These will allow water to evaporate into the atmosphere, irrigate plants, and reduce the volume of rainwater flowing into the river. By keeping much of the rain water out of the sewers, we’ll have extra capacity to serve new developments and improve our resilience to floods in the downstream sewer network. We can also reduce the size of the sewer pipes needed, as well as the associated pumping and treatment requirements.
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One way we’re managing the unavoidable impacts of climate change on our business is to reduce our greenhouse gas (GHG) emissions. We have set ourselves a challenging goal to become zero net carbon by 2030 for our operational activities. We’re currently around 60 per cent of the way towards this goal. Whilst we haven’t yet identified how to get to net zero, we’re investigating how we will achieve this over the next few years. There are emissions associated with the delivery of water and wastewater services and the use of electricity from the national grid. We’re acting to reduce our operational emissions by enhancing our understanding of them, becoming more energy efficient, and generating our own renewable electricity. When we’re not able to generate our own renewable electricity, we source renewable grid electricity. Therefore, combined with our renewable self-generation, this means 100 per cent of the net electricity we consume is from renewable sources. In 2018/19, we generated 22 per cent of our own electricity needs from renewable sources including sludge, wind and solar power. We have two wind turbines at sites in east London and Solar Panels at 43 sites, including Europe’s largest floating solar panel array which was installed in 2016 at our Queen Elizabeth II Reservoir. The low carbon and renewable energy produced by the solar array is used to help power nearby Hampton water treatment works. Most of the renewable electricity we self-generate comes from the treatment of sludge. This reduces our greenhouse gas emissions and is the equivalent of over £32 million a year in energy savings. Sewage sludge is an energy rich resource, with a high calorific content which we extract as biogas and use to generate renewable electricity. We’ve been producing renewable energy at our larger sewage works since the 1930s, mainly with Anaerobic Digestion (AD). By investing in our infrastructure and using a combination of methods and new technologies such as Thermal Hydrolysis Process (THP) and Pyrolysis, we’re able to increase the amount of renewable energy produced from sludge. As well as helping to reduce our carbon emissions, it also improves resilience by reducing our reliance on grid electricity and makes even better use of a valuable resource. We are continuing to find ways to use less energy by being more efficient, making more of our own renewable energy, and continuing to invest in low carbon operational processes and assets to achieve our challenging goal to become zero net carbon by 2030 and help mitigate the impacts of climate change.
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Walthamstow wetlands The impacts of climate change may often seem a long way off, but in simple terms they’re just a long term shift in the frequency and intensity of extreme weather. Over the past few years alone, there have been several extreme weather events which have all significantly affected our ability to deliver essential water and wastewater services to our customers, including:
Summer 2018 – joint hottest summer on record
Late February and early March 2018 – ‘The Beast from the East’
October 2016 to March 2017 - the driest period since 1995/96
In 2014 - the wettest English winter since 1766
The floods of 2013/14
In 2012 - the wettest summer for 100 years
Drought in 2010/12
Each of these extreme weather events made delivering the service our customers expect very challenging. Although it is not possible to attribute these weather events to man-made climate change, they represent the type of weather we expect to see more regularly in the future.
We have therefore incorporated learning from these events into our long-term planning to better understand future risk, to increase the longer-term resilience of our services and to ensure that customer bills are no higher than they need to be. It is widely accepted that climate change is a real issue and a major challenge to society. However, it’s almost impossible to predict the extent and timing of its impact.
We believe that a twin track approach of managing the unavoidable impacts of climate change on our business (‘adaptation’), combined with reducing our greenhouse gas emissions (‘mitigation’), is essential if we are to manage the challenges that climate change represents.
An important part of our approach is the need to work with other organisations to develop resilient responses to the impacts of climate change, and to reduce our greenhouse gas emissions. We know we can’t do this alone, so we’re continuing to work collaboratively with our customers, employees, partners, suppliers and regulators to create opportunities to better understand what we can do.
We will be posting a blog every day this week to highlight how we’re reducing our contribution to climate change by reducing carbon emissions and how we’ve been adapting to the impact of climate change, with two recent examples - ‘The Beast from the East’ and the joint hottest summer on record.
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