Messing about with the river

How did the River Sid's valley originally form, and how has its course changed naturally over time? The Sid valley likely formed from melt waters during the Pleistocene epoch, leaving a broad valley with a "misfit stream". As the climate warmed, the river became a meandering stream with a low gradient. Coastal changes also played a significant role; a shingle ridge grew eastwards due to longshore drift, pushing the river's outlet to the east over post-glacial times. Historically, the river's mouth fluctuated east/west, and a major storm in 1322 shifted the lower reaches significantly eastwards. What are the primary ways human activities have altered the River Sid's course and characteristics? Human intervention has significantly modified the River Sid. These changes, primarily for flood protection and historical land use, have resulted in a river that is straighter, armoured in places, confined by walls, and impeded by weirs. This has altered its natural erosi...

Sidbury Much of the upper reaches of the River Sid are inaccessible to the public as it flows through private land and the first real public access point is in the village of Sidbury. In Sidbury there is a popular 'park' called the Millennium Green .... to be continued! Sidford The river passes under the A3052 at Sidford where, of course, the crossing was once a ford. The terrain here is fairly level and so the river slows down and shingle deposits start to build and the river is fairly shallow. Alders line the banks here and the bank side vegetation is influenced here by the agriculturally improved pasture on either side. A footpath runs along the eastern bank of the river for a short way here.  Fortescue After Sidford the river is less accessible for a stretch and then reappears at Fortescue where there is a footbridge carrying a footpath from the upper Byes path across to the hamlet of Fortescue. The river continues to be relatively slow moving to the north of the bridge and...

What is the current ecological health of the River Sid, based on invertebrate surveys? Based on surveys of river fly invertebrate populations (larvae and nymphs of species like mayflies, stoneflies, and caddisflies), the water in the River Sid is considered reasonably healthy, although not entirely pristine. The presence of targeted river fly species indicates a functioning ecosystem, as these invertebrates act as "canaries in a coal mine" for water quality. The presence of kingfishers, which require clean, well-oxygenated water with fish, also suggests a relatively healthy river environment. What are the main physical modifications impacting the River Sid's ecosystem? Significant physical modifications impacting the river include weirs, particularly the large weir in The Byes, which acts as a barrier restricting the upstream movement of aquatic life, including migratory sea trout and European eels. Coastal structures like the training wall and East Pier also impede sedim...

What are the main invasive species impacting the River Sid catchment? The primary invasive species causing significant issues in the River Sid catchment are Himalayan Balsam, Japanese Knotweed, and Signal Crayfish. Himalayan Balsam and Japanese Knotweed are problematic plants found along the riverbanks, while Signal Crayfish are an invasive freshwater crustacean present in the river itself. How do invasive plant species like Himalayan Balsam and Japanese Knotweed affect the River Sid environment? Himalayan Balsam and Japanese Knotweed are considered "significant issues" and can form dense stands that out compete native plant species. This leads to a reduction in the diversity and structure of plant communities, which are crucial habitats for native wildlife. Himalayan Balsam is particularly widespread, infesting over 50% of the River Sid's length. What are Signal Crayfish and why are they considered a serious invasive species in the River Sid? Signal Crayfish (Pacifastacu...

What are the main goals for managing the River Sid? The primary objectives for the River Sid's future management, particularly driven by the River Sid Catchment Group, are multifaceted. A key focus is improving the overall health of the river system, which includes enhancing the fish population and mitigating the severity of rapid water level increases (flashes) after heavy rainfall. A significant long-term aim is to facilitate the movement of sea fish to upstream spawning grounds, potentially by creating a bypass around the school weir in The Byes, which currently acts as a major barrier for species like sea trout, Atlantic salmon, and European eels. Beyond these specific targets, there's a broader goal of improving the physical condition of the river. How are efforts addressing the challenges faced by fish in the River Sid? Efforts to improve the River Sid for fish are focused on removing or mitigating barriers to migration. The large weir in The Byes is a significant impedim...

What are the typical physical characteristics of fast-flowing rivers and streams? Fast-flowing rivers and streams typically originate in upland areas with high rainfall, steep slopes, and impermeable ground. They are essentially erosive systems, constantly transporting sediment downstream. These waterways are characterised by turbulent waters with marked variations in flow speed. The speed of the water dictates the type of sediment on the bed; faster sections tend to be gravelly as finer particles are washed away, while slower areas may accumulate sand and gravel. Substrates in fast-flowing sections are often too mobile for plants to establish easily. How does the water chemistry of fast-flowing rivers differ from other aquatic environments? Fast-flowing rivers and streams are generally nutrient-poor. Their turbulent nature means the water is highly oxygenated, which is beneficial for organisms with high oxygen demands. However, they are susceptible to pollution from agricultural runof...