BART is currently planning to deliver the removal of a small weir at Castlefields Park, Calne, Wiltshire, with the aim of improving freshwater habitat throughout the park.
This weir is impacting sediment movement as well as passage to a number of fish species. The impoundment caused by the weir has resulted in fine sediment smothering riverbed gravels which in effect impacts habitat availability for an array of invertebrates and fish. The flow conditions upstream of the weir are uniformly slow resulting in very little depth variation or diversity of habitats. Often this is not ideal habitat for the flora and fauna that should naturally occupy the river. Removing the weir will generate flow diversity, improve river bed habitat as well as reconnect up and downstream habitat. Essentially, weir removal restores nature’s ability to heal itself.
Whilst there are weirs located both upstream and downstream of this structure, the removal of this weir will provide an opportunity to share learning with local interest groups, and perhaps provide stimuli and interest for addressing other weirs along the river.
BART plan to deliver follow up restoration to the river channel, including the installation of woody debris to narrow the channel where it has become overwide because of the artificial weir structure. We’ll be delivering the project in partnership with Calne Town Council and Bowood Estate whom, are both land and asset owners. We are incredibly grateful to The Halpin Trust who have funded the delivery of this work.
This project will complement wider river improvement works carried out by BART locally, including the removal of two boulder weirs on the Marden near the confluence to the Bristol Avon, a series of habitat walkovers of the majority of the river to identify opportunities for river habitat and water quality improvements, several kilometres of in-stream habitat enhancement works, establishing a network of Riverfly monitors whom sample on a monthly basis, a large number river dipping and a Yellowfish campaign.
Over the course of the next couple of months, we’ll be rolling out a digital education platform with local schools that will promote the sustainable usage of water, including measures that children, their families and their school could take to reduce their impact on our local rivers. Lessons will introduce children to the local wildlife that depend on their local rivers and how we can all do or bit in protecting our river environments, including the roll of Sustainable Urban Drainage (SuDS), such as rain gardens and water butts. Please keep an eye out on our website and social media for further updates.
For further information regarding this project, please contact us at simon@bristolavonriverstrust.org
