In the village of Ashe, near Basingstoke, an unassuming pool sits in a secluded field. But to those in the know, this is a very exciting place indeed: the source of the famous River Test. About a mile down the road, in neighbouring Overton, the iconic waterway takes a more recognisable form. It can be spotted at many points across the village, and perhaps the most popular is a footpath known as Flashetts.

If you’ve ever walked along Flashetts, you’ll know what a special place it is to visit. It snakes alongside the chalk stream, making it a great place to enjoy a globally rare habitat type. Dragonflies and kingfishers are frequent visitors. At the western end of the footpath, the river and wet woodland have been designated a Site of Special Scientific Interest, earning them further legal protections.

Unfortunately, this local gem had deteriorated in recent years. Significant bank erosion was threatening the stream's wildlife and destabilising the bankside trees. Without intervention, this popular walking would have become increasingly dangerous and devoid of life. This was brought our attention by both residents and the landowners of the Flashetts & Quidhampton Mill Conservation Area.

Pictured below (click to expand): The Upper Test and Flashetts footpath before the restoration work. The bank erosion and accumulated sediment are visible.

Muddy waters

The stream's poor health had several interconnected causes. Dense trees cover was reducing light levels, limiting the growth of bankside plants; without these root systems to secure them, the banks were more likely to erode. The footpath's popularity meant that its surface saw a lot of wear, and much of the displaced material ended up in the water.

These factors resulted in a chalk stream that was overly wide and shallow, and was also receiving more sediment than usual. Shallow water is prone to overheating, which depletes the dissolved oxygen - a disaster for many chalk stream species. As the water spread out, it flowed more slowly; this caused more sediment to drop out and settle on the stream bed.

This sediment smothered the gravels, pushing out the invertebrates who live among them. It also prevented some fish from breeding - the brown trout, for example, lays its eggs in 'redds' on the stream bed. This involves digging in the gravel, and the eggs need flowing water to deliver their oxygen. With sediment in the way, digging would be difficult and the eggs could suffocate.

Pictured below (click to expand): The Upper Test and Flashetts footpath after the restoration work. Several brushwood berms are visible, as is the gradual clearing of sediment from the gravelly bed.

A clean slate

In August of 2022, the Watercress and Winterbournes partners were able to tackle this problem. Wild Trout Trust took the lead, with support from Wessex Rivers Trust. Working with the site's landowners, they thinned the trees and let in more light. The trimmed branches were then used to make woody bundles called 'berms'. With the help of our amazing volunteers, these were fixed at key points in the stream.

The berms create narrow ‘pinch points’ in the stream channel, which speeds up the flow. The increased speed and depth of the water will help fish to travel through the area; this is important because impassable places can isolate wildlife populations, leaving them more vulnerable to disease and pollution.

While much of the accumulated sediment will be swept away, some will be trapped within the berms themselves, where it will encourage plants to grow. Once established, this vegetation will shield the bank from further erosion and create habitat for animals like dragonflies, brown trout, and water voles.

The final step of the restoration work focused on the footpath itself. We added a top layer to replace the material lost through erosion, and also topped up the gravel in the popular paddling spot at the Station Road end. This will ensure that residents and visitors can continue to enjoy this beautiful spot, while helping it to cope with high footfall in the future.

Cherishing our chalk streams

We were delighted to improve the health of this precious chalk stream through the Watercress and Winterbournes Landscape Partnership Scheme. With projects spanning habitat restoration, wildlife monitoring, youth education, and community engagement, why not see what the scheme has to offer?

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