Eradication of Floating Pennywort from the upper Cam.
This was a major and successful project, although it was considered by some to be “impossible” when we started.
Floating pennywort (Hydrocotyle ranunculoides) arrived in the upper Cam in about 2012, and by 2016 it completely covered the river for months, extending as far upstream as Grantchester. In 2017 Cam Valley Forum set up the ‘The Pennywort Project’ with the aim of eradicating floating pennywort from the upper Cam within 5 years. During 2018 we engaged contractors to clear the bulk of the pennywort and the tree banches that were trapping Floating Pennywort. This was then followed by volunteers and individuals seeking out and removing strands as they appeared. We ran several working parties, several of them in partnership with Cambridge Canoe Club. By 2021 the Cam above Cambridge was pennywort free, and has remained so, although we remain vigilent.
We then turned our attention to the Cam between Cambridge and Baits Bite Lock. By 2025 this downstream stretch was largely pennywort free, although there are occassional outbreaks, particularly around Fen Ditton. Further downstream of our area of activity (eg Ely) the situation remains dire.
The Rush project
The Rush. November 2017
The Rush, a much earlier course of the Cam through Cambridge, winds its way across Sheep’s Green to the Newnham Mill Pond. Before 2017 its flow was restricted by an old inoperable sluice. We suggested that this should be replaced to enable a brisker flow. This idea was taken up by Cambridge City Council which, with additional funding from the Environment Agency, installed a fish pass as part of a new sluice. Although we have some reservations about the outcome, the fuller flow has been widely welcomed by the public, as well as by the fish.
Grants and support for other organizations
When funds have permitted, we have made small financial contributions to river-related restoration projects run by other local groups. These include extensive improvements to the Cam as it flows past Trumpington Meadows. Those works, carried out by South Cambridgeshire District Council, helped to make the river more accessible in some places for people and, in other places, to protect the most sensitive wildlife sections from increasing public pressures.
We have inspired the formation of new local voluntary groups devoted to caring for a nearby watercourse. A workshop convened by Cam Valley Forum, for example, demonstrated innovative techniques of river restoration carried out by the Friends of the River Shep and this inspired two delegates to establish the River Mel Restoration Group, which has since done splendid work on the nearby River Mel at Meldreth.
More recently we helped establish the Cam Catchment Partnership
For further examples of our work, see our newsletters