Met Office helps South West Water deal with extreme rainfall
30 April 2013, News release from Met Office
With weather conditions having such a significant impact on the performance of the water industry, it is essential for water companies to know how, and when, to respond.
Preliminary research from the Met Office suggests we may have seen a change in the nature of rain we get with an analysis of rainfall events since 1960 indicating that the number of 'extreme' days of rainfall may have become more frequent. With this in mind, the Met Office has helped South West Water predict when river conditions will be difficult or expensive to treat.
During periods of heavy rain, debris and soil is washed into rivers which have to be filtered to remove the debris before going through a treatment process. This removal can increase production costs by up to five times.
South West Water commissioned the Met Office to conduct a weather sensitivity analysis to determine the relationship between rainfall and turbidity. The measurement of turbidity, the cloudiness or haziness of a fluid, is a key test of water quality.
The Met Office used turbidity data from a remotely operated river monitor and rainfall data, to establish a relationship. This information was used to set up a forecast service to help South West Water manage resources and minimise the impact of high turbidity events.
South West Water is now able to predict when river conditions will be difficult or expensive to treat. Keeping a close eye on changing events, the Met Office provides guidance to South West Water's Central Control Centre. When there is increased probability of extreme rainfall, South West Water can remotely alter the volumes of water in the distribution network which supplies its customers. This in turn means that South West Water can slow down the production rate at its treatment works.
In many cases this avoids additional filtering all together helping South West Water to run its assets more effectively, reducing costs to customers and reducing impacts on the environment. Michael Wigmore of South West Water said "The solution was designed and delivered to one of SWW's works in Cornwall and has proved so successful that we are continuing work to establish the possibilities of implementing it on our river sources in Devon".