Tag Archives: Dover

Improvement Works on the River Dour

By Chris Gardner

In 2015 the South East Rivers Trust was awarded a £31k grant through the Department of Environment Food and Rural Affairs (DEFRA) Catchment Partnership Action Fund (CPAF) to deliver fish passage and habitat improvements on the River Dour in Dover. All these improvements would be designed to increase the health and resilience of the river environment for fish and other species, to meet the requirements of the EU Water Framework Directive.

River Dour an Urban Chalkstream

The River Dour is a short (4 km) little chalkstream that rises in a rural setting but soon flows through the highly urban centre of Dover. This delightful little river boasts a healthy brown trout population, but the habitat is highly degraded due to urbanisation and impounded / fragmented due to a legacy of watermills.

A spotty brown trout

We assessed the urban part of the catchment by walkover survey, looking for potential projects. These were then prioritised on a cost-benefit basis, resulting in four sites where fish and eel passage could be addressed. Two were simple fish and eel passage easements and two were sites for eel passes.

The ruins of the old water mill at Minnis Lane.

Work began in October 2015 with a volunteer event at Minnis Lane near the aptly named village of River. An old watermill ruin at the site presented a complete barrier to fish and eel passage. The main part of the weir was very high and a fish pass here would have been way beyond the budget available. However, a parallel channel had one small step weir and an over wide shallow section of channel upstream that made this route impassable. To make this passable to fish and eels, we fitted a wooden box to the downstream end of the small step weir had a wooden box, to raise the water level up the step so fish could navigate it. We also used faggot bundles as flow deflectors to define a deeper channel through the over wide shallow section. Many thanks to Anita for helping to organise the volunteers and to the volunteers for their hard work! You know who you are!

Fixing in the faggot budles at Minnis Lane

In May 2016, we also fitted two eel passes to Halfords Weir and Lorne Road weirs. These are large weir structures that will require technical fish passes in the future to make them passable to fish, but eel passes were achievable with the budget we had available. The Halfords weir site was quite straightforward – the setup of the weir allowed a simple gravity-fed pass to be fitted. Eel passes allow eels to move over weirs through a piece of conduit which contains brush bristles that provide a crawling medium. Water passes through the pass to provide attraction flow and passes are located at the edge of the weir as studies have shown that eels predominantly use river margins as migration corridors.

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The Lorne Road site was more complicated, because this eel pass needed to go up and over the weir, so a gravity-fed option wasn’t appropriate. Instead, we designed this pass to be fed with a water pump to provide attraction flow. Many thanks to Malcolm and Mick at the Lorne Road Mill building who allowed us to tap into their power supply! Also many thanks to Paul and Simon for their work building the passes – your help was very much appreciated.

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We delivered the final aspect of the project later in spring 2016. Morrison’s weir (near Morrison’s supermarket) presented a barrier to juvenile life stages of trout and eel. To improve its pass-ability, the weir was notched in the middle to provide a streaming flow that fish can swim up, instead of a small drop and a thin plunging flow that fish can’t easily negotiate. Bristles were also fitted into the notch so eel could climb up.

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Wise words from Baton Path Mural

Delivery on the Dour

Last month, we ventured all the way to Dover to start delivery of our River Dour Restoration Project.

The Dour is a short river, roughly 4 km in length, which runs into the sea at Dover Harbour.

We were addressing fish passage at a weir near Kearsney Abbey at Minnis Lane. Here the Dour runs through a ruined building, causing blockages to fish passage with the presence of several small weirs. The river itself has started to create its own bypass channel and our aim was to enhance this channel to allow fish passage upstream of the site.

Minnis Lane Site

Installing Brash BundlesTo do this, we installed brash deflectors to concentrate the flow of water to a narrower section, ensuring there was enough flow for fish to swim up without becoming stranded.

We were joined by 6 local volunteers on the day to help us install 12 brash deflectors in the stream.

Each deflector was secured in place with hazel posts and wire to ensure they stayed in place in higher flows.

By placing the deflectors so that they’re pointing upstream, we directed the flow of water into the middle of the channel, creating a deeper section for fish and eels to swim up.

We will be back to finish the site off soon and see how our deflectors are working.

Many thanks to our volunteers who helped on the day: Bethany, Katharine, Lilian, Ray, Simon and Tom. And a big thank you to the local Scout Club for letting us park our van in their carpark.

So before….

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After!

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Exploring the Dour

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The South East Rivers Trust team spent a fascinating day earlier this month getting to know the Dour – an urban chalkstream which flows into Dover Harbour and is strikingly similar in many ways to south London’s Wandle and Hogsmill.

Guided by our new local partners from the Dover Society, the White Cliffs Countryside Partnership and the Environment Agency, we walked almost the full length of the river from its perennial headwaters near Kearsney Abbey downstream via Crabble Corn Mill to the point where it almost disappears completely into culverts under car parks in the centre of Dover.

Very encouragingly for the future, we spotted several healthy-looking trout, as well as what was clearly a shoal of sea trout desperately trying to jump a weir that is probably impassable even in the highest water: a golden opportunity to start thinking about fish passage solutions for this lovely little urban chalkstream!

Update: Our visit to Dover has now been reported in a longer feature on Flyfishing.co.uk: click here to read it in full