In the hamlet of Little Ann around 700m of the Pillhill Brook runs through an area called The Water Meadows. Despite many years of careful management, the chalk stream has recently seen a decline in its once-healthy brown trout population. Keen to support this iconic local species, the landowner decided to call in some expert assistance.
The Wild Trout Trust led on delivering a solution through Watercress and Winterbournes, in which they and the Wildlife Trust are both partners. Site visits revealed that the loss of brown trout was caused by excess sediment on the stream bed - this is a problem for fish as it means shallow water, fewer invertebrates to eat, and insufficient oxygen for egg development.
In a healthy stream, the water's movement removes material from some areas (a process called 'scour') and deposits it in others. This forms a varied, meandering channel in which the water moves fast enough to carry sediment away. However, if environmental pressures introduce sediment or slow the flow then the stream can become overly shallow and sluggish.
The partners therefore aimed to not only restore the stream's fish habitat, but also maintain it by tackling the root causes of its reduction. We checked the area for water voles, and scheduled the works for October to avoid fish and bird breeding seasons. Then it was time to get cracking!