ABOUT THE TAMAR LAKES PROJECT

Tamar Lakes during eutrophication episode

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.

Farmers attending a Soil Management & Cross Compliance Workshop

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.  

FARM WORKS
The aim of the Tamar Lakes Catchment Project is to help farmers and landowners undertake works that separate farming activities from the watercourses in the Tamar Lakes Catchment.  This is done to improve water quality and increase biodiversity.   Such works include watercourse fencing to restrict access by livestock, and the fencing of vulnerable ecosystems such as woodland, wetlands and carr.  But it also includes more subtle measures such as helping farmers with the infrastructure they need to improve clean and dirty water separation, slurry and FYM storage.  Farm works also include improving livestock tracks, outdoor feeding areas, culverts and bridges.  All of these works aim to reduce the levels of sediment and dung that enter the watercourses, smother out gravels and thus reduce the populations of invertebrates which occur at the bottom of the food chain.  In addition, farmers within the catchment are offered free soil testing to help them build a nutrient budget which often results in the reduction of bought-in inorganic fertilisers.  This reduction of field applications results in a reduced risk of run-off into the watercourses.   Farmers are also invited to attend free workshops on the latest research into issues such as soil compaction, out-wintering cattle and the most recent changes to the cross compliance regulations. 

Some Tamar Lakes farmers with the Project Officer

PARTNERSHIPS
Partners include:

• The Farmers of the Tamar Lakes catchment.
• The Tubney Charitable Trust
• The Westcountry Rivers Trust
• The Environment Agency
• South West Water plc
• The South West Lakes Trust
• Defra

Stream where livestock have unlimited access, before fencing works		After fencing works – stream is now protected
Before fencing works, livestock have eroded banks introducing sediment to stream		Formalised drinking point, after fencing