Client:
Severn Trent Water (STW)
Providing Fresh-& Wastewater services
for 4.6 million households and businesses across the Midlands and Wales.
Deliverable:
Provide a co-designed operational weather service and
consultancy for STW,
to help mitigate
weather impacts,
manage resources & maintain safety across the business.
Outcomes:
The service helps STW to maintain supply by reducing losses, highlighting process faults and planning for variations in demand.
The Challenge
As the climate continues to change, increasing strain is being placed on the water cycle. Drier summers with heavier thundery downpours and milder winters mean balancing water resources and sustaining contracted services to customers is becoming increasingly difficult for all Water Utility Companies. This is further exacerbated by these drier summers being accompanied by warmer temperatures causing water demand to dramatically increase.
The variability of our winter weather can also lead to rapid swings in temperature, causing the ground and the pipes within to shrink, expand or move, and finally burst. This results in a loss of supply and leakage when resources should in fact be recharging.
Meanwhile, during periods of high rainfall and low evaporation, wet wells may rise significantly, increasing the risk of pumping stations breaking down and sewage being released into the environment. A tailored weather service provides the advanced warning and insights required to plan ahead, mitigate risks and maintain supply and safety.
“The weather information that is provided to us is critical to what we do every day, setting our operating rhythm for all our services and how we manage our assets below ground and above ground along with many staff that are working in and around these assets. Heavy rain affects our sewage network, high winds can bring down power lines – affecting pumping stations, high temperatures cause increases in demand and cold temperatures and dry spells cause ground movement and broken pipes. This is why good weather information is so important.”
Mark MacLeod, Resource and Improvement Manager, STW
The Service
WaterQuest
For Water Utilities we offer our modular WaterQuest service, providing you the flexibility to design your own tailored service package. These include daily PDF weather briefings, site-specific forecasts for asset locations, customised weather warnings based on your own thresholds, sub-seasonal and seasonal forecasts, and an online Forecast Web Portal. Our forecasters can also join your team tele-conferences. We also offer three water and wastewater indices: the Burst Pipe Index, the Water Demand Index and the High Wet Well Index. Each of these has been co-developed with our clients, based on their deep knowledge, practical experience and telemetry data.
The Outcomes
Overspills
We help STW to identify the main cause of each flood/overspill event by providing historical localised rainfall totals for the flood location, helping the company discriminate between natural extreme rainfall events and faults in their infrastructure or processes. This helps STW deliver on their Water Resource Management Plan and in reporting requirements to Ofwat.
Swing Index
Our forecast ‘Swing Index’ (Burst pipe index) highlights the rate of air temperature change from negative to positive. During the winter of 2022, the UK suffered a sudden cold spell during the first half of December and, according to the Met Office, the subsequent maximum daily temperature change (‘swing’) from the 18th to the 19th was the third largest in records back to 1960 (see graph to left). This caused more than 100 burst pipes for STW (as recorded in their Ofwat response), but our forecast assisted with planning and recovery, reducing the number to near zero in just five days, reducing leakage and supply outages. STW reported a 93% increased performance in downtime reduction compared to previous years.
Resource Management
During the warmer drier months, especially as the climate continues to change, our forecasts inform near-term water resource management planning. Based on our forecast solar radiation/sunshine hours and temperature data, STW managers assess current supply levels and project when additional resource is needed in order to match supply and demand. This was especially useful to STW during the summer of 2022, when temperatures across the UK exceeded 40oC, avoiding the need to enforce any Temporary Use Bans (TUBs).
Operational Rhythm Meetings
WeatherQuest meteorologists also occasionally join key decision makers at STW during operational rhythm briefings. They give further insight and forecast confidence during times of high-impact weather events that may lead to Operational Bronze or Silver thresholds being exceeded. This enhances communication and promotes understanding between the STW and WeatherQuest teams.