In Spring 2024 a number of volunteers set out to walk the watercourses of the Worth Valley to assess the current potential for fish passage along the River Worth. For both long-range migratory fish such as Salmon and Sea Trout alongside in river fish such as brown trout. Read about what we found ...
The results show a river that is heavily blocked by a large number of weirs and other barriers to fish passage, with 128 weirs recorded across the catchment. These weirs stop fish from swimming up-river to breed in the headwaters, where more gravel bars form providing the key habitat needed for fish to shelter their eggs and feed their young. Weirs also prevent natural sediment transportation down the river which allows the formation of natural gravel-based fish breeding habitat in the lower reaches of the river.
We also identified a number of long culverts where the river travels underground in man-made tunnels. These deter fish from entering side streams due to the lack of daylight, artificially smooth riverbeds and shallow water flows.
Using the data gathered by our volunteers Aire Rivers Trust staff have undertaken a prioritisation exercise to establish which weirs along the Worth pose the largest problem for fish passage and require the most immediate work to re-connect the river for wildlife. The results showed:
The first priority lies with the largest weirs on the Lower Worth between Mytholmes and Stockbridge. Easing fish passage along this lower stretch of river grants access for long-range migratory fish such as Salmon to all of the other tributaries of the Worth. With particular focus needing to be placed on three main impassable weirs:
The second priority lies with the daylighting of the North Beck culverts near Keighley Morrisons, and passage of the North Dean chain of weirs. This will grant access to the high-quality spawning grounds found at Holme House Woods, below Laycock. With fish passage above Goose Eye to be looked at as a later priority.
The third priority lies with the passage of the redundant weirs of the Upper Worth between Ponden Mill and Mytholmes, connecting large sections of high-quality fish breeding grounds in this rural section of the river.
Finally, the lowest priority lies with achieving passage along Bridgehouse Beck from Oxenhope, through Haworth to Mytholmes. Out of the three main upper tributaries, this beck contains one of the biggest barriers to fish passage in the form of Ebor Mill Dam, which carries a public road as part of its structure, which will be extremely difficult to pass.
Alongside the beck facing issues from heavy structural modification, discharge from a sewage treatment works and ongoing urban flooding problems, this makes it the tributary that presents the least potential for fish breeding opportunities.
You can explore interactive maps of our findings and to learn what can be done to ease fish passage along the River Worth click on the story map below to see the results, or on this link to display the Story Map full screen:
