Our Work
Opening the Sid
Opening the Sid
Introduction to the project
Project Dates: 2022 – ongoing
For many years local people have been trying to make improvements to the river. One such improvement is to to reinstate fish migration from sea to river. This would have major benefits for the river valley and the species it supports. Opening the Sid is a long term project that works towards opening the river for migratory fish so that they can move freely through the river system and access optimum habitats needed for different stages of their lives.
Key Aims:
- To identify good habitats in the river for fish species and make improvements where necessary
- To modify barriers to facilitate fish migration
- To ensure the aesthetics of any barrier adaptations are in keeping with the existing qualities of the catchment
- To review flood risk management with any barrier adaptations
What are the strengths and weaknesses of the River Sid?
Generally speaking, our strengths include abundant clean gravels, good quality well oxygenated water and a wide range of habitats with deep pools, runs and riffles and good hiding and resting places. For example the area above Fortescue provides excellent habitat. Left to its own devices the river has created deep meanders and plentiful side channels where juveniles can shelter during times of high flow. Fish species supported in the River Sid include three IUCN red listed species, these are Atlantic Salmon, European Eel and Brook Lamprey.
Our weaknesses include the many weirs making fish migration more difficult. A few weirs are completely impassable but could be modified. Water is impounded behind weirs creating more homogeneous less desirable habitats. Straightening the river, and then protecting the sides from erosion with walls, degrades natural habitat. When in spate the river rises rapidly after heavy rains. High river levels and the catchment’s steep gradient means that the danger of eggs and young fish being swept away is very real. This can be addressed by modifying habitat to create more sheltering areas and putting in natural flood management schemes to slow the rate of run off occurring during and after heavy rain. Other projects in the valley are addressing the problems athat arise from spate conditions.
The main obstacle impeding fish migration
This is School Weir, which is situated near the mouth of the river and, being one of the largest weirs in the South West, is an absolute barrier to sea trout and salmon migration. It is also a significant obstacle to eels. The issues in resolving these problems at School Weir are not to be underestimated. In addition further barriers along the river present additional challenges for fish movement.
Trout Population
The 2023 and 2024 electrofishing surveys within the catchment identified problems in the resident trout population. The numbers of trout fry found are low when compared to the adult trout in the river. This means the adult population is not being adequately repopulated. In order to address this, we need to understand how trout live and identify the limiting factors in the river system, which the project could address. The barrier to sea trout returning to spawn is one significant factor but in addition the river environment needs to be returned to a more fish friendly state.
Requirements for a healthy trout population
Trout need clean, oxygen-rich water, diverse habitat
structure, suitable substrates, a variety of water flow
patterns, connectivity between different areas of the river
and abundant food resources. Different life stages need
different habitats, so the river system must provide a
mosaic of conditions.
During spawning, clean gravels and good quality, well
oxygenated water are necessary for egg development.
The young fry require microscopic plankton and then small invertebrates to feed on. They live in shallow areas unsuitable for adult fish who might regard them as a tasty snack. They can hide in the river gravel or in river vegetation.
As they grow into trout parr they seek what are termed nursery habitats, side channels with reduced water flow rates and well vegetated river margins. Weirs can disrupt the movement of fish into these areas. Aquatic plants and woody debris provide shelter from predators.
Adult fish need deep pools, riffles, and runs for feeding, resting, and migrating. Aquatic vegetation, undercut banks and woody debris provide shelter for the adult fish. They should be able to move freely to access a variety of habitats and ensure a plentiful food supply of invertebrates and smaller fish. They move upstream to spawn and downstream to migrate. Some trout remain in the river but given the opportunity some would head for the sea and return some years later to breed.
Sidmouth Town Council, the Sid Vale Association, the Devon Wildlife Trust and Environment Agency have all engaged with these problems and now the River Sid Catchment Group, in partnership with the Westcountry Rivers Trust, have set up a project called Opening the Sid to tackle these issues.
The Westcountry Rivers Trust
The Westcountry Rivers Trust (WRT) are an experienced and respected charity that have expertise in both barrier modification and river habitat improvement. Dr Dan Osmond is our project manager and Hannah Parvin our project officer. In 2024 the River Sid Catchment Group and the WRT formed a partnership, through the generosity of a local benefactor, to appraise the situation, liaise with the public and develop proposals for establishing full fish migration and river habitat improvement in the valley.
Partnerships
Opening the Sid is a partnership project with Westcountry Rivers Trust aimed at understanding the extent and impact of barriers to migratory fish within the Sid. Delivery will focus upon building a knowledge base through habitat walkovers and barrier assessments, progressing options for technical passage on the super fragmentor (School Weir) and delivering habitat improvements and easements around less formal barriers within the Sid. This project has attracted one year partnership funding and it is hoped that this will enable and attract further funding for wider delivery for Opening the Sid.
The Course of Action in 2025
Walkovers
To assess the location of barriers in the river and the opportunities for habitat improvement the WRT project officer will visually assess the riverside and all its major tributaries. This survey will identify multiple issues and form the basis of decision making for future works.
Opening the Sid is a partnership project with Westcountry Rivers Trust aimed at understanding the extent and impact of barriers to migratory fish within the Sid. Delivery will focus upon building a knowledge base through habitat walkovers and barrier assessments, progressing options for technical passage on the super fragmentor (School Weir) and delivering habitat improvements and easements around less formal barriers within the Sid. This project constitutes one year partnership funding and it is hoped that this will enable and attract further funding for wider delivery for Opening the Sid.
Barrier Improvement
Previous reports on school weir will be reevaluated and then a design for modification will be generated that satisfies fish migration and gains the support of the town. The Environment Agency will be fully engaged in the decision-making process and foremost in their support will be the consideration of flood risks within the scheme.
The walkover survey will identify other impassable and partial barriers to migration and will enable works to be prioritised.
In order to demonstrate to the town the benefits of barrier modification, we are intending to select one of the barriers in the Byes for modification this year. This will enable understanding of the benefits of this work early in the project.
Habitat Improvement
A visual assessment of the whole of the river system will develop a clear understanding of the quantity and quality of fish habitat available in the river. With an understanding of current fish populations and having surveyed the habitats within different stretches of the river, a program of habitat work will be compiled and some priority areas tackled this year.
2026 and Beyond
With the survey work completed, with public support and a clear picture of the needs of the river in place, it is hoped that an extensive program of work can be funded and implemented in 2026 and beyond to restore fish migration and ensure a good riverine environment for a burgeoning fish population.
If you have any queries, please email info@riversid.org
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