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Cam Valley Forum

The Cam Valley Forum is a voluntary group, established in 2001, which works to protect and improve the environment of the River Cam and its tributaries. Our members comprise both individuals and affiliated organisations including Abington RiverCare, Bourn Parish Council, Cam Sailing Club, Cambridge Trout Club, Cambridge University Angling Club, Cambridgeshire Mammal Group, Camrowers, Comberton Parish Council, Duxford Parish Council, Friends of the River Shep, Grantchester Parish Council, Linton Parish Council, and Waterbeach Angling Club. The Trumpington Farm Company also supports the forum as a corporate member.

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Chairmanís report to the Annual General Meeting on Cam Valley Forum's work 2015-2016

Floating Pennywort working party on the upper Cam, Saturday 1st April 2017

The invasive Floating Pennywort has in recent years colonised the lower Bourn Brook, the River Cam and some of its minor tributaries, and is affecting an SSSI near Wicken. It is also spreading down river on the River Ouse and has been found as far down river as the Denver Sluice. Since 1990, when it was first found in the wild on the River Chelmer in Essex, it has spread rapidly and each year the number of affected sites is expanding exponentially. In high season there are long stretches of the Cam where dense mats reach out towards the centre of the river, and in one part it has grown from bank to bank. It is a threat to bio-diversity, a nuisance to river users and could increase the risk of flooding.

This week contractors for the Cam Conservators have been removing as much as they can from the upper Cam by mechanized means, but inevitably this will leave floating remnants and inaccessible patches. If left, these remnants will soon grow. The Cam Valley Forum and associates are organising a major volunteer punt day on Saturday 1st April on the upper Cam, and we are inviting you to join us. The target is to remove as much as possible on the day, from Byronís Pool to Scudamores boat station. Scudamores are kindly giving us ten punts for the task, which will need a minimum crew of one experienced poler, a raker and a netter. And just as important, we also need people on the bank to rake out easy-to-reach Pennywort and to help with lifting out filled bins from the punts and to dispose of the material on the bank. Not everyone feels comfortable on a punt in which case a bank job would be ideal. Up to forty people may be required to take this project forward and we hope that you have the enthusiasm and time to be part of this unique experience.

If you would like to take part, or have any queries please contact Mike Foley (Cam Valley Forum) on

We envisage a early start time between 9 Ė 10 am and those punts that go the furthest (Byronís Pool) will not necessarily be out for longer as there is much to do in the Grantchester Meadows area. It would be very useful if you could supply details of your experience, how long you want to be involved, and whether your role would be on land or on water. An indication of whether you possess a long handled rake and are prepared to bring it would also be useful.

More detailed information will be available to those who express an interest.

work on river
trees by river

Are you a river lover? Like to help protect and improve a stream near you?

Over the centuries many of our winding streams have been deepened and straightened into drainage ditches. The reeds, the meadowsweet and the purple loosestrife that grew on their shallow edges and provided a home for warblers, dragonflies and water voles were scraped away. Willows and alders were grubbed up, and the increased silt washed off the fields smothered stretches of gravel where the brown trout used to lay its eggs. Now local authorities, the Wildlife Trust and local river groups are working, with the help of volunteers, to restore some small rivers and streams to a more natural state, making them friendlier for wildlife and more attractive for people.

On 9 May potential volunteers gathered at a workshop in Barrington Village Hall to learn about the various ways in which they might help in this work. They also visited a stretch of the River Shep near Barrington, to look at what the Friends of the River Shep have done in previous years.

If you would like to become a volunteer, we would love to hear from you. Email Jean Perraton or Ruth Hawksley, indicating any particular interest or expertise, and also where you live.

The river brings an almost continuous green corridor through the heart of Cambridge and provides links out into the countryside. For centuries the river's low lying wet meadows have provided valuable flood protection for the city.

Although parts of the riverside are carefully protected and managed, in recent years much of its wildlife value has been lost with intensive farming and the fragmentation of semi-natural habitats. The Cambridge area is now under pressure to accommodate considerable growth of housing and employment. It is vital that this growth respects the character of the riverscape setting. The best features must be protected, and conditions improved for wildlife to flourish and for people to enjoy the river and its environs.

The upper Cam between Newnham and Grantchester.
© Christine Jennings
Grantchester Meadows carrying out its traditional function of holding flood 
water and protecting the city.
© Christine Jennings
The otter has been returning to the Cam and its tributaries, but much work 
remains to be done.
© John Green
Pollarded willows are a traditional element of the Cam landscape, but need 
management and replacement.
© Christine Jennings


The Cam Valley Forum is worried that the current demand for water from agriculture and domestic users is already putting a strain on the hydrology and ecology of the river Cam and its tributaries. And, with the rapidly increasing population of this area, the problem is likely to get worse.

The Cam valley used to be a much wetter environment - but with much the same rainfall. There were numerous watermills even on its tiniest tributaries such as the Mel, the Shep and the Wilbraham rivers. People used to swim in the Granta at Linton where now there's barely enough water to paddle. The flow there nearly ceased this summer, and by November this year the Cam near Sawston had only a third of its normal flow. In the drought of 1976 the springs at Nine Wells lost their SSSI status when they dried up, killing the rare fresh water invertebrates. Now the other streams that supply designated SSSIs, such as at Fowlmere, Fulbourn and Ashwell, are prevented from running dry by compensatory pumping from the chalk aquifer.

We cannot be certain how climate change will affect this problem but the general consensus is that our summers are likely to get drier and hotter. Although the winter rainfall may increase it is likely to become more erratic, leading to faster run-off and flooding rather than replenishing the aquifers. The Environment Agency has for some time been concerned about the level of abstraction from the river and the chalk aquifer, and is seeking to revoke some extraction licences, but this involves costly compensation.

Meanwhile the population, and its demands for water, continue to grow. Cambridgeshire's population has grown from about 190,00 in 1961 to 620,000 today. And the population of Cambridge City, about 122.000 today, is planned to increase to 150,000 by 2022. The forum has produced a position paper on water sustainability to stimulate discussion on this issue, and is seeking the co-operation of local academics to carry out in-depth studies into the future demands for water in the Cam catchment area.

Will there be enough to meet reasonable human needs?
What will be the impact of more abstraction and changing climate upon the river and its wildlife?
What could and should be done to ensure water sustainability?

The forum has also responded Cambridge Water Company's draft drought strategy expressing concern that it fails to consider adequately the threats to the environment. If you would like a copy of this response, or our position paper on water sustainability, please contact Jean Perraton

Pollution hot-line

If you see signs of pollutants being discharged into a river or stream - or any other action which threatens the river environment - call the Environment Agency's free 24 hour hotline: 0800 80 7060

All pictures on this website are copyright and may not be reproduced without permission.

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