Explore the River Sid in Devon, the county's smallest river. Learn about its unique 'flashy' nature, Triassic geology, and the best spots for nature walks in Sidmouth
The River Sid is a fascinating geographical feature in East Devon. Measuring just over six miles (10.5 km) in length, it is recognised as the smallest river in the county. Despite its size, the Sid has a dynamic nature and a significant impact on the landscape it carves through.
The river begins its journey high above the coast, characterized by a steep gradient that fuels its energy.
Origin: The Sid rises 206 metres above sea level at Crowpits Covert (near Putts Corner).
Gradient: It has a steep average gradient of 20m per Km, which provides the energy necessary for rapid erosion.
Geology: The valley is formed of Triassic mudstones and sandstones, with a mix of acidic and basic soils containing flints and clays.
Catchment Area: The river drains an area of approximately 40 Km².
Geographers describe the Sid as having a "very flashy" catchment. This means the water level can rise and fall dramatically within just a few hours in response to rainfall.
Discharge: While the mean daily discharge is 0.574 m^3/sec, it is highly variable.
Erosive Power: During heavy rain, the river becomes an "eroding system," capable of scouring tributaries and transporting everything from fine particles to large boulders.
The "Red" River: Intense run-off from steep fields often washes soil and nutrients into the water, causing the river to turn a distinctive red colour.
As the Sid flows south, it is joined by several smaller streams and passes through historic villages.
Tributaries: Key feeders include the Snod Brook, Roncombe Stream, Wool Brook, and Snail Breck.
Settlements: The river flows through the villages of Sidbury and Sidford before reaching the town of Sidmouth.
The School Weir: A notable feature often described as a "waterfall" along the river's course.
The River Sid has been significantly altered by human intervention, which has impacted both its flow and its ecology.
Modifications: Channels have been straightened, embanked, and armoured—most notably at The Ham, which was historically a marshy floodplain.
Barriers to Wildlife: A large weir built in The Byes during the 1970s restricts the movement of migratory fish like salmon and eels.
Pollution: Issues such as overgrazing, artificial fertilisers, road run-off, and sewage effluent mean that few parts of the river remain unpolluted.
For those looking to experience the river first hand, several areas offer excellent public access and nature observation:
The Byes Riverside Park: A major green space between Sidford and Sidmouth featuring water meadows and wildlife habitats.
Margaret’s Meadow & Gilchrist Field: Managed specifically for wildlife, including a pond and new hedging.
Sidbury Millennium Green: Offers a view of the river flowing through parkland with native riparian plants.