The scheme is designed to ease pressure on environmentally sensitive local water sources in West Cumbria, and provide a secure, long-term supply for the area.
It will also involve the construction of new water treatment works, two service reservoirs and a new pumping station.
The £300m project is broken up into several work packages which have seen several firms involved already in the design process under early contractor involvement deals.
A joint venture between Northern Irish contractor Farrans and Atkins drew up detailed plans for a large 13km pipeline from Thirlmere reservoir in the Lake District to Bridekirk.
Its route from the reservoir will loosely follow the direction of A591 northwards through Keswick, passing east of Bassenthwaite, before turning due west towards Williamsgate.
From Williamsgate treatment works a new treated water trunk main will deliver water to Summergrove service reservoir near Whitehaven.
J Murphy & Sons previously signed a £1.3m design contract covering its early involvement in this section of the project.
Full works packages are out to tender with contract awards expected shortly.
In total, five existing water treatment works will also be decommissioned once the new pipeline is commissioned. These will be at Ennerdale, Cornhow, Quarry Hill, Buttermere and Thirlmere.
United Utilities aims to start construction of the major four and a half year project in March 2017.