Barhale and North Midland Construction are to deliver four major projects for Severn Trent Water.
The joint venture will carry out three tunnelling schemes and one pipeline job on the Elan Valley Aqueduct.
The 117km-long aqueduct, which was opened by King Edward VII in 1907, is being improved by Severn Trent as part of its Birmingham Resilience Project.
Barhale and North Midland will use an earth pressure balanced (EPB) tunnel boring machine from Herrenknecht to deal with rock strengths up to 190mpa and 10bar of external water pressure.
Murphy & Sons earlier this year began piling work on the Elan Valley scheme.