Rewilding the Dearne

From October 2020-22 Riverlution collaborated with The Friends of the Dearne and the local Countryside Officer for Denaby Dale Parish Council to carry out a series of environmental enhancement works and community engagement activities. This project was funded by Yorkshire Water PLC and was centered on 0.75 km of the Upper Dearne that runs upstream of Litherop Lane, surrounding the Clayton West Sewage Treatment Works.??

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The issues with the river?

For several years, the Friends of the Dearne have been monitoring the health and condition of the river in the Upper Dearne Catchment by River Fly sampling. The further downstream section of the site displayed reduced diversity and richness of aquatic macro-invertebrates, as evidenced by repeated sampling.??

In response to the concerns raised by the River Fly sampling, Paul Gaskell of the Wild Trout Trust completed a thorough scoping study for the location in 2018. Three significant stream stressors that were probably influencing the river's ecology were identified in the scoping report.?

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Numerous tests in this area revealed a variety of problems. The first problem was that the lower part of the channel was shallow, had little variation in the channel's environment, including little shade and tree cover, and was over-widened, which was thought to be caused by cattle access to the riverbank. The river also suggested high nutrient levels, which can cause waterbodies to lose dissolved oxygen due to the increased growth of bacteria, fungi, and algae in the channel. The last issue that we found was that?the River Dearne's gravels were being blocked by fine sediment inputs, which decreased the instream habitats' complexity and quality and disrupted fish and invertebrate life cycles in key locations.??

Project outcomes?

Using the scoping report, Riverlution and the Friends of the Dearne collaborated to create a winning grant proposal for Yorkshire Water. At the River Dearne location, several useful projects, community engagement initiatives, and monitoring operations were made possible by Yorkshire Water funding.?

Successes??

Buffer Zone Fencing - A livestock exclusion fence was installed to create a buffer strip along the river to improve the riparian habitat and protect the river. A 650-metre stock proof fence was installed at the downstream left bank of the site and alongside a tributary on the left bank in early summer, 2021. The fenced off section has created a 5- to 10-metre-wide riparian buffer strip, protecting the bank from the negative impacts of the livestock and allowing a more diverse bankside vegetation to establish.?

Installing Heather Bales as Leaky Dams - The Friends of the Dearne volunteers worked to create a series of leaky dams within a straightened drainage channel which enters the Dearne. The volunteers staked and secured 16 heather bales within the small tributary channel to slow the flow during spate, divert run-off into riparian buffer-strips and reduce nutrient rich sediment run-off.?

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Balsam Bashing - Himalayan balsam is a fast-growing shallow rooted invasive non-native annual plant species, which outcompetes native vegetation and leaves riverbanks susceptible to erosion after the plants die back in autumn and winter. Both in the upper Dearne catchment and at the Rewilding the Dearne site, balsam can be found. In the past few years, as part of the Rewilding the Dearne Project, members of the Friends of the Dearne group have been actively involved in significant "Balsam Bashing" throughout the upper Dearne catchment. By using local expertise to manage balsam at the most upstream position in the upper Dearne catchments, Friends of the Dearne have adopted a strategic, catchment-scale approach.?

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Creation of a Mini-Wetland Area - By eliminating the terminal portion of a tile/field drain that was draining the field on the left bank, a small amount of wetland habitat was created. Excavating the soil made it possible to remove multiple buried fields drain sections, a?drainage channel was made by landscaping the area, and fence was put in to keep livestock out. To slow down the flow of water, leaky dams were built, and species of wetland plug plants were planted to assist filter agricultural runoff before it entered the River Dearne.??

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Tree planting - After the end of the Yorkshire Water funded project, additional funding was secured from White Rose Forest to plant 1000 trees at the Rewilding the Dearne site. The trees were a mix of native broad leaf species including goat willow, grey willow, alder, field maple, wild cherry, rowan, birch and oak.??

Ongoing and Future Work?

Riverlution has maintained their collaboration with the Friends of The Dearne?under the River Stewardship Skills Scheme. Friends of the Dearne volunteers have provided tours of the site and given presentations on river fly monitoring to participants in the Stewardship Skills Scheme.?Furthermore, the Stewardship Skills Scheme Group has collaborated with volunteers from Friends of the Dearne to perform additional practical enhancement and maintenance tasks both at the site and in other locations.

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