Cambridge University Botanic Garden’s lake, constructed in 1857-58, is to be dredged for the first time in the Garden’s history.
The decision to dredge the lake is a result of a series of professional, analytical studies, culminating in a report confirming that the lake is heavily silted, with a water depth of just 0.3m in places, and stating that its biodiversity and ecology is suffering due to silt depth and oxygen depletion.
The process of clearing and dredging the lake is estimated to take twelve weeks, beginning at the end of November.
Once complete, the lake will have an enhanced ecosystem, the removal of dominating plants will provide the opportunity to open up vistas from a horticultural perspective and the process will also ease the management of the lake.
“High levels of silt are impeding plant development and also mean that particular plants such as waterlilies and reeds are dominating the lake,” said Beverley Glover, director of Cambridge University’s Botanic Garden.
“Silt is also building up on root mass in and around the lake and affecting the shrubs and trees both in the lake and on its edges.
“It’s important that the lake provides a thriving habitat for wildlife and plants as well as a safe area for staff and visitors.
“We know the lake’s condition will never naturally improve and, without intervention, the lake would eventually silt over entirely and become a swamp.”
The last time the lake was empty was a result of the drought in 1976; it also reached very low levels in the 1980s but it has never been dredged in its history.