Introduction

The Lower Tamar Lake was constructed by the Bude Canal Company in 1819.  Its purpose was to transport sea sand for soil improvement on the local farmland.  The lake was used as the main water supply for Bude until 1978.  Following an engineering inspection the embankment at the lower lake was considered unsafe and lowered.  The lake became a nature reserve, and loss of this resource resulted in the construction of the Upper Lake. 

The Upper Tamar Lake was completed in 1975.  The area of the reservoir is 32.2 hectares, with a drainage catchment area of 1320 hectares.  The lake is used as a direct supply of drinking water.  The surrounding land-use is agricultural, with dairy being the main industry.  Within a few years a series of eutrophication episodes resulting in algal blooms occurred at the Upper Lake. 

The Environment Agency and Tamar Riparian owners became concerned about water quality both in terms of fitness for human consumption, as well as for fish stocks and associated wildlife habitats. When a eutrophic episode ocurrs the oxygen within the body of water is rapidly depleted, resulting in a hostile environment for all but a few organisms.  This has a deleterious effect upwards throughout the food chain, subsequently causing a reduction in biodiversity.  Investigations showed that eutrophic episodes occurred at the lakes as a result of internal (stratification resulting in the sudden release of nutrients from lower sediment layers) and external (agricultural run-off) nutrient loading of the Lake.

It was decided that the solution would lie in a two-pronged approach.  South West Water plc would install a destratification programme to combat the internal nutrient loading element, whilst the Westcountry Rivers Trust would engage with farmers and landowners to tackle the external nutrient loading occurring as a result of agricultural practices.   Since the Westcountry Rivers Trust is an environmental charity, its main focus is to promote water quality and increase biodiversity.  With generous assistance from the Tubney Charitable Trust, the Tamar Lakes Catchment Project was formed.