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lynher and tiddy
Ref: B04d

The river Lynher is 34km long, rising at a height of 280m on Bodmin Moor and flowing into the Tamar Estuary at Plymouth. It drains a 245km2 catchment and has four main tributaries, one of which - the river Tiddy - supports a population of Atlantic salmon. There are many smaller tributaries including Deans Brook, Withey Brook, Marke Valley and Darleyford streams and Kelly Brook. 75% of the Lynher catchment is populated by specialist dairy farms. In addition, there are also a small number of beef and sheep farms and some arable land producing potatoes and maize, both crops having a significant water demand in the summer.

There is light silty clay loam soil throughout much of the catchment, with an underlying geology predominantly of slate, limestone and grit in addition to granite on Bodmin Moor. This geology dictates low primary permeability and porosity which , in turn, limits groundwater flow and storage. The River Lynher is "a hard working river". Historical mining activities (particularly in the headwaters) have led to the contamination of watercourses to varying degrees by metalliferous compounds such as zinc and copper. Arable farming, particularly potato and maize cultivation, has been increasing which can result in soil erosion leading to poor water quality and the subsequent siltation of salmonid spawning gravels. Few fields in the catchment are truly level so bare soil in winter is easily washed down the slopes in heavy rains. On the light silty soils, gullies are easily formed acting as pathways for the transfer of large quantities of soil and nutrients from the land to adjacent water courses.

River Lynher at Clapper Bridge
River Lynher at Clapper Bridge

The River Lynher is an EU designated salmonid fishery throughout much of the catchment. It supports both a rod and line, and commercial licensed net fishery for migratory salmonids (Atlantic salmon and Sea trout); the river also supports a Brown trout fishery. Stock monitoring data obtained from the Environment Agency indicates that over the last 20 years the salmon population, particularly the multi-sea winter stock component, has undergone a severe decline. Further concerns have been raised with regard to a shortfall in spawning targets and low juvenile survival from fry to par stage (Salmon Action Plan, EA 1998).


The Lynher estuary is a designated Site of Special Scientific Interest (SSSI) and a Special Protection Area (SPA). Many species can be found here, including rarer species such as the kingfisher, otter, dipper, avocet, black tailed godwit and the triangular club-rush.

  produced by the WESTCOUNTRY RIVERS TRUST as part of the CORNWALL RIVERS PROJECT  
 

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