Landowners
& Habitat Survey

2026 Landowners Meeting

In March 2026, we hosted a landowner meeting to provide a summary of the habitat survey results, and invited guest speakers to talk about how they may be able to help projects within the valley to support the ecological health and resilience of the catchment. You can download their presentations below:

Download the presentation ‘RSCG – Dr Dan Osmond – Opening the Sid River Habitat Surveys’

Download the presentation ‘RSCG – Sir George Cave and Simon Browning – Natural Flood Management’

Download the presentation ‘RSCG – Milly Bowden – Land Management, Water Quality and Quantity’

Download the presentation ‘RSCG – Jack Hirst – EDNL – Supporting the Sid Valley’

2025 Habitat Survey Results

The results of the habitat survey have landed!

The final report can be downloaded below to read at your leisure. We’ve created a brief summary to help you get an overview of the findings, and a summary about the barriers along the river. We’ve also sectioned out the report by stream/river, so you can jump to the information that’s most relevant for you.

Download the 2025 River Sid Catchment Habitat Assessment

Summary of the River Sid Catchment Assessment 2025

The report assesses fish habitat and migration barriers across the River Sid Catchment, surveying over 22 km of river. It finds that the catchment contains a generally good mix of habitats suitable for different life stages of salmonids (e.g. trout and salmon), particularly in the River Sid, Snod Brook, and Roncombe Stream.
 
However, fish populations are severely limited by barriers to migration. A total of 102 barriers were identified, with School Weir highlighted as a complete blockage preventing species like Atlantic salmon and sea trout from accessing most of the catchment. As a result, salmon are largely absent, and trout are only found in limited areas.
 
Other key issues include bank erosion and sedimentation reducing habitat quality, river modification (e.g. straightening, culverts, concrete channels), invasive species adversely impacting the river bank. Suggestions for additional tree cover are identified.
 
Despite these pressures, the report concludes that the catchment has strong potential for ecological recovery if connectivity is restored.
 
Main recommendations:
  • Removal or modification of major barriers (especially School Weir)
  • Improvement  of river habitat complexity and restoring natural processes
  • Planting and managing riverside vegetation
  • Creation of  buffer zones to reduce erosion and pollution
  • Control of  invasive species
Priority for restoration should focus on the River Sid, Snod Brook, and Roncombe Stream, where improvements would deliver the greatest ecological benefits.
 

Habitat Walkover by Stream

We’ve broken the main report down into individual rivers and streams to help you jump to the section that’s most relevant for you. Click on the section to view the reports for each waterbody.

Summary of the barriers

The photos collectively illustrate that fish passage in the catchment is heavily constrained by a large number of mostly artificial barriers, with concrete weirs and culverts posing the greatest problems, while many smaller barriers present practical opportunities for relatively straightforward improvement. [notching, removing boulders or adding material]. Download the full barrier report below:
 
Download the Barrier Appendix
Widespread Presence of Artificial Barriers
There are numerous man-made structures across the catchment that create significant vertical drops or shallow, fast flows, making them difficult or impossible for fish to pass:
  • Concrete weirs (often large and steep) e.g. School weir
  • Culverts (frequently perched or undersized) e.g. 
  • Bridge aprons and footings e.g. Buckley Bridge over Roncombe Stream
  • Ford crossings reinforced with concrete or boulders e.g. Sidmouth
 

Concrete Weirs Are the Most Severe Obstacles

Large weirs (e.g. School Weir, Sidford Mill Weir) appear near-vertical and impassable. 
Even smaller concrete weirs are significant barriers to migration,
they often have thin “laminar” flow (too shallow for fish) and no suitable resting pools.

Culverts Frequently
Create Barriers

Culverts are concrete-lined channels with straightened or engineered sections. Many culverts are perched (water drops at the outlet), too shallow or smooth inside and restrict natural flow patterns and have small but critical drops (10–30 cm) that still prevent fish passage.
 
RSCG - Culverts
Example of a Culvert along Snod Brook
Boulder and check weirs are widespread but often partially passable 
Boulder and check weirs have multiple flow routes and small pools, with some passable conditions, especially in higher flows. However, they can still impound sediment and reduce habitat qualit. Many may be considered low priority or easy improvements.
 
RSCG - Bouldre Check Weir
Example of a boulder or check weir along the River Sid
Modified Channels Reduce Habitat Quality

Modified channels are concrete-lined channels and straightened or engineered sections. These create a uniform (homogenous) flow, and a lack of natural features like pools and gravels reducing both habitat diversity and fish passage.

RSCG - Modified Channel Bed
Example of a modified channel along the Lincombe Stream

Barrier Prioritisation

From the habitat survey, the Westcountry River’s Trust have created a priority order for the barriers to be worked on. We’ve pulled out the first and most urgent priorities. There are 9 further pages to cover the full 102 identified barriers. You can view the full list from page 158 of the Barrier Appendix.

2025 Habitat Survey Intentions

In 2025, we contacted riparian landowners along the River Sid and its tributaries to ask for permission for Westcountry River’s Trust to access their land to carry out habitat surveys. We wanted to survey the journey of migrating fish to understand what barriers and obstacles they face, and quality of river habitats improving access for migrating fish and eels.

What did surveying involve?

Surveying is a non-invasive process carried out by up to two people. It is a simple walkover visually assessing and recording river habitats and in stream structures as in the photograph.

Hannah Parvin was the Westcountry Rivers Trust Project Officer responsible for the walkover survey. The map below is an example of the output from a walkover survey showing habitat types, bankside features and points of interest within the river.

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