The Midford Brook is formed by convergence of the Wellow Brook and Cam Brook at Midford before passing Tucking Mill andreaching the village of Monkton Combe. This section of river was historically a leat stream feeding a mill, with a large weir downstream of the site. For the purposes of hydropower, the river was straightened and over-widened throughout the whole of the project stretch.
Today, the river has somewhat recovered as it has started to re-meander itself and the weir at the bottom of the project site has collapsed, leading to increased flows. However, decades with a lack of significant flow has led to a huge amount of silt accumulation, in quantities that would take several years to be flushed through if left to recover naturally. This silt is smothering gravels essential for invertebrates and therefore is limited fish life within the river.
This project involved the creation of 6 flow deflecting brushwood berm structures along 0.46km of the Midford Brook. These structures have several benefits:
- To concentrate low summer flows, ensuring sufficient depths of water at all times and therefore cool and well oxygenated flows.
- To concentrate and scour gravels during winter flows, cleaning gravels of silt
- To collect silt on the structures (which will then vegetate and form part of the natural bankside) that would otherwise smother gravels
- To increase habitat availability within the stretch of river, including cover from predators, ambush cover for fish predators and newly created riffles, pools and backwaters for a variety of fish life stages.
- A secondary benefit of improving angler access to the river.
These structures have shown immediate benefits in flow conditions with new riffles and pinch points created throughout the stretch of river. We are hopeful that one particular pinch point that has been created in this project will provide flows and less compacted gravels suitable for trout and grayling spawning. We look forward to observing the success of the structures following a season of winter flows.
The cooperation of the Avon and Tributaries Angling Association was essential in the successful delivery of this project and we are grateful for support and interest we have received from this group.
We are extremely grateful to Wessex Water for funding this project.