The lake is home to rare species of fish and birds

Phosphorus in fertilisers can lead to excessive growth of plant species such as algae, which can harm lake wildlife.

The new computer model uses data to identify areas in the lake's catchment at risk of polluting the water.

The lake is home to some of the UK's best wildlife, including ospreys and endangered Ice Age fish vendace.

'Action plans'

Bassenthwaite is a shallow lake and, combined with high rainfall, steep mountains and key farming and forestry areas, it is recognised as being a nationally sensitive area for water quality.

It is one of four places in England chosen for the three-year Catchment Sensitive Farming (CSF) project.

The area's CSF officer, Karen Austin, said of the project: "It will allow me to target the farms that can benefit most from my advice and assistance.

"Working with farmers, I will be able to point out which fields pose difficulties and help with management and developing achievable action plans to tackle problems."