The Anglian Water region is home to some of the fastest growing cities in the country, so continuing to save water and manage excess rainwater effectively is essential to continue meeting the needs of the company’s six million customers. Anglian Water’s Innovation Shop Window Project Manager, Nick Sexton, explains how the company is utilising technology in a bid for resilience while relieving pressure on the region’s water and sewerage network.
The East of England faces enormous climate change challenges. The increasing extremes of weather and ever-growing population, means surface water management (SWM) is an important tool in securing the future resilience of our waste water network. Harsh and sudden storms coupled with the effects of population growth bring acute SWM issues to the region.
One such problem, known as urban creep, sees an increase in hard surfaces, such as extensions, patios and paved driveways and means less and less rainfall is collected by plants, trees and soil, ultimately allowing more surface water to flow directly into sewers. There is also a significant amount of rainfall entering our system from property downpipes. The challenges presented by too much rainfall over a short period of time differ greatly from those presented by too little rainfall over longer periods, but we recognise solutions can be holistic and address both issues where possible.
A long-term, multi-faceted challenge, requires a long-term strategy. And with that, we created a 25-year SWM plan that recognises the importance of removing unwanted surface water from our sewers to ensure serviceability, resilience and capacity for future growth. To achieve this, we are testing novel ways to engage communities with the challenge of reducing rainwater flows into sewers with innovative installations, which have the added benefit of providing an alternative non-potable water supply for use in the home and garden.
The installations involves the disconnection of downpipes into the sewer and redirecting them into a Sustainable Drainage System (SuDS) feature, such as a swale or rainwater tank. Whilst these alternatives are not new in themselves, the challenge of delivering them on a large scale, and achieving positive societal and environmental change using exploratory new technologies, is a new challenge for the water industry.
The success of the long-term SWM plan relies on customers actively engaging with us to make sure any assets are maintained in the long-term. But what is in it for customers?
One of the biggest challenges with SuDS is that they require a repurposing of small amounts of urban land, and people don’t always like change. So, it’s critical to take people with us on the journey through communication that listens to and engages with people’s emotions. We developed the ‘Make Rain Happy’ brand to support our project and it has a simple principle. Rain is happy if it ends up in a green space or in rainwater tank, but it’s sad if it lands on an impermeable surface or in our sewers. The rhetoric resonates with all age groups, providing justification for SuDS without the over-complication of climate change, population growth and resource management.
SuDS and SWM aren’t widely recognised concepts by the public, so engagement to install traditional SuDS may only get us so far. To explore how technology could benefit our communities and SWM, we have collaborated with experts outside of our current supply chain to take our solutions to the next level.
We are working with OTA Water – a sustainable water management company – to utilise near-real-time data solutions at customers’ properties to provide a real change in our management of surface water. This is taking place in Newmarket, our Innovation Shop Window location – a real-world test-bed trialling the latest technology, systems and process in one environment. Our unique relationship with customers here has allowed us to test previously unproven technologies and approaches as a community, rather than a silent service.
Working with 11 customers, ourselves and OTA Water have installed two rainwater harvesting systems, two 800-litre water butts, six 300-litre water butts and one rain planter. OTA Water’s technology monitors the water level, water and ambient temperature, and water flow rate (where appropriate) at each property and has the built-in capability to remotely monitor and control the draining of these tanks into our network. This control will allow us to establish whether the ability to alter attenuation and discharge of surface water can influence successful future SWM, whilst ensuring access to non-potable supplies for customer’s homes.
Following commissioning of these installations in Autumn 2018, OTA Water has demonstrated the systems performance during and after rainfall. Utilising the data collected from each tank and characteristics of each site, including customer demand and forecasted rain, the system can operate to provide the necessary storage for an upcoming storm.
Illustrated above, (fig1), a predefined volume of water is discharged from a water tank, so further storm water can be captured during the next storm. This illustrates the capability to successfully manage decentralised storage and control the volume and timing of discharge to the sewer system. The impact is particularly significant where several tanks work together to generate an optimum discharge, whether these are locally led by the ‘master’ tank or connected to a centralised management system.
OTA Water has developed control algorithms and proprietary software that enables them to monitor and manage rainwater at a plot-scale. The system was developed building on intellectual property licenced from The University of Exeter’s Centre for Water Systems. Their software predicts spill events and takes actions to release rainwater (either to green space or into the network), thus freeing capacity for coming storms.
CEO Dr Peter Melville-Shreeve describes the system: “It has taken our team several years to develop the platform and control algorithms to enable deployment in a cost-effective manner. It is really exciting to see our assets in the field performing so well. With our StormSenseTM technology, we can help customers capture and reuse rainwater, whilst maximising capacity to mitigate flooding during intense storms.” Benefits are also being seen on customers’ bills – at a property where a rainwater tank is feeding a toilet and washing machine we’re seeing an average daily demand reduction of 95 litres.
Initial results indicate that this technology provides the capability to control the release of surface water into our sewerage network when it has been collected at customer properties.
Alongside OTA Water, we’re working to understand how this control can help alleviate the pressure storms cause on our sewerage network and serve the needs of our customers with water for non-potable use. Our Newmarket installations provide us with data to understand how customers are using water from the tanks so we can ensure this need is always met, even when we plan to drain tanks to mitigate storm flows to sewers.
The next phase of work is investigating how we successfully install disconnection features at a community scale. We want to understand the potential for these when we have a knowledge of forecasted rainfall, current sewer levels and customer demand of water. An understanding of both engagement and technology is critical to the successful evaluation of this approach.
A street in Newmarket, which is near a school where we have installed SuDS previously, is a location where we know surface water is entering the sewer. This dense urban area and high number of properties provides us with an important and challenging location to trial the technology on a larger scale. By completing disconnection work at the school and landing the ‘Make Rain Happy’ message, we have already warmed the community to our work and its purpose, in anticipation of another targeted engagement and installation programme.
We are working with OTA Water to understand how the tanks could work together when installed at numerous properties on the same street, against the performance of the older, traditional ‘leaky’ water butt – a water butt which discharges a pre-determined amount to provide capacity for storm events. The OTA Water StormSenseTM software enables us to model a range of low and high-tech SuDS devices for a given site. This ranges from leaky water butts through to smart rainwater control systems driven by real-time rainfall data provided by our modelling team using ICM Live.
Through evaluation workshops, we have been working with OTA Water to understand the value of plot-scale SuDS and rainwater reuse systems, and how control systems can help us to test different strategies in a real-world setting. This is to ensure our future investment in these technologies provides maximum benefit for both Anglian Water and our customers.
Our work with OTA Water is providing us with a wealth of knowledge for our long-term approach to SWM. We see it as having the potential to alleviate the ever-increasing pressure on our existing infrastructure, whilst providing a sustainable, long-term solution to longer periods of dry weather.