New moves to protect famous Cambridge chalk stream
Water and environment agencies are taking joint steps to prevent taps running dry by announcing measures to protect Cambridge’s famous Hobson’s Conduit chalk stream. .
The environment agency, Cambridge water company and the Trustees of Hobson’s Conduit have set out plans to address the environmental impact associated with water abstraction, particularly involving all-important chalk streams such as the 400-year-old Conduit.
They have issued a joint statement on the future plans for less water abstraction from the Conduit at Nine Wells - one of 160 chalk streams in the UK.
Pete Aspley, wholesale director of Cambridge water company, insists there is no threat of a drought in the region as yet and are planning to safeguard supplies in the future.
He said: “We are closely monitoring the situation in conjunction with the environment agency.
“We are not at the point where we believe a drought should be declared. We have suffered from some exceptionally low levels of rainfall and without it, ultimately the whole system isn’t sustainable in the long term.
“There’s no imminent risk of anyone’s taps running dry, as there are adequate supplies to meet everyone’s demand at the moment but we’re really conscious of the environmental impact associated with the abstraction of our water.
“We’re working very closely with the Cam Valley Forum and the EA and we’ve limited the volume that we abstract and reduced our licence capacity in order to make sure we minimise that environmental impact. We’ve done that by using some alternative sources and moving water around. However, in the longer term with the continued growth in population we are going to find it increasingly difficult to do that.
“New developments will have a significant impact on demand. We’re planning ahead and looking at our 25-year planning and investment strategy in order to make sure we’ll be able to meet everyone’s demands.
“Lower than average levels of rainfall and groundwater recharge over successive winters have led to low flows in the springs at the Nine Wells nature reserve in late August and early September. Since May last year only three months have recorded above average rainfall in East Anglia and the Cam has been one of the worst affected catchments.
“A run of dry autumns and winters have resulted in a prolonged period of reduced effective rainfall and recharge. This, combined with the permitted abstraction, has led to groundwater levels falling to exceptionally low levels, not seen since 2012 and before this the mid 1990s. Spring activity at Nine Wells is closely related to groundwater levels and very low levels mean springs are now drying up.
“The recent failure of the springs also led to a severe reduction in water levels along the historic Hobson’s Brook and Conduit, which has been flowing from Nine Wells to the Conduit Head in Cambridge for more than four hundred years. The flow has only been interrupted on two occasions in four centuries and both of those are within living memory. The main influence on the springs drying up has been lack of rainfall, exacerbated by the impacts of abstraction. We know that abstraction by Cambridge Water does impact on the flow of the springs but there is a scheme in place to mitigate against this starting from April 2020.
The EA and Cambridge water company have agreed how much impact abstractions have on the springs and a solution to support the spring flows, along with voluntary changes to licences is being put in place with effect from April 1, next year. By augmenting the springs at periods of low flow and with proper site and channel management this will help to safeguard the biological health and amenity value of the springs and Hobson’s Brook. Although Cambridge water had hoped that the scheme could be completed earlier than planned, difficulties due to the site location have meant this has not been possible.
Pete Fox, director of water, land and biodiversity at the EA, said: “The last three winters have been exceptionally dry and we have an on-going environmental drought across the region.
“There is no doubt that this has been caused by the climate emergency. There is also no doubt that it is having a devastating effect on our chalk streams.
“English chalk streams are one of the most precious and beautiful things in the natural world. They are known for their clear waters, rich wildlife and for providing a beautiful place for people to enjoy.
“Chalk streams flow from chalk aquifers, stores of underground water that are replenished when it rains. Some groundwater levels in the South East are now at the lowest level ever recorded.
“Sections of chalk stream regularly stop flowing during drier periods but low groundwater levels are causing longer stretches than normal to dry up.
“Chalk streams and chalk aquifers provide essential drinking water for people across the South East. Some water companies such as Cambridge Water are 100% dependent on this source of water. Without it taps would run dry.
“Businesses and farms also rely on chalk streams. Without water they would not be able to operate. This would significantly affect the economy, the livelihoods of the people that they employ and the availability of the food we eat.
“Balancing the needs of people and the environment is a challenge and it is getting harder. We are working flat out to limit the damage the dry weather is having and to ensure that water supplies are sustainable for the future. This includes taking immediate action to restrict the amount of water taken, developing long-term plans to reduce our reliance on chalk streams, working with partners on projects to improve water quality and stepping in to limit damage to wildlife and the environment when river levels are too low.
“While we have to take water from the environment to live, a process we call abstraction, we have got to make sure that abstraction is sustainable.We regulate water abstraction through our licensing system. By reviewing licences and reducing the amount of water people can take we have returned 16 billion litres of water back to chalk aquifers and streams since 2008 and removed the risk of another 14.9 billion litres being taken. This is equivalent to the average annual domestic water use of approximately 300,000 people – similar to the population of Nottingham.
“We are also introducing new licences for thousands of people and organisations that have previously been exempt to further regulate the amount that is taken.
“But abstraction regulation can only go so far. Longer-term solutions are dependent on extensive and costly infrastructure such as new reservoirs and pipes to transfer water from other parts of the country. Detailed plans for the new infrastructure that we need are currently being drawn up.
“We are also working with numerous partners on a wide range of innovative projects to improve water quality.
“Since 2011, our partnership work on over 60 projects has driven improvements to more than 70 kilometres of chalk streams at a cost of £4.3 million.
“By using less and looking after what we have, we will be able to prevent even more devastating droughts in future and ensure that we have clean and plentiful water for generations to come. But we will only achieve this if everyone takes action now.”
Howard Slatter, Chairman, Hobson's Conduit Trust, added:“A combination of unpredictable winter rainfall and large scale abstraction by water companies has led to extremely low water flows this summer, and the likelihood of this repeating ever more frequently in future.
“Hobson’s Brook in Cambridge, with its source at Nine Wells, is one example of this problem.We are fortunate that there is a planned augmentation scheme, due to be implemented by April 2020.”
More by this authorAdrian Curtis
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