A water company has said it will have to dig up the main A217 in Surrey because of opposition to an alternative route across heathland.
Sutton and East Surrey Water said disruption to traffic would be unavoidable as it laid the main from Mogador to Burgh Heath.
The company wanted to lay the pipe across Banstead Heath but Banstead Commons Conservators refused consent.
The conservators thanked everyone who had supported their campaign.
Sutton and East Surrey said the £2.5m main was needed to carry water from Mogador to storage reservoirs three miles (5km) away at Burgh Heath and would improve water supplies for customers in the Sutton area.
The plan to lay the pipe across Banstead Heath, an area popular with walkers, dog walkers and horse riders, was first put forward last year.
It was rejected by the conservators on the grounds that it would have "considerable damaging effects to our local environment".
The water company said continued opposition had prevented any progress.
"The only options were to pursue a Commons route and probably end up with a public inquiry involving the Secretary of State, or to find a viable alternative," said operations director Mike Hegarty.
"The Commons option would have probably lost us another year, been very costly and offered no certainty of a positive result.
The new route will start in fields owned by Reigate and Banstead Borough Council and and on private land beside the heath before joining the A217.
Work is expected to start later this year.
Banstead Commons Conservators said on their website they would like to thank all those people who had been so supportive of their campaign against the pipeline over the past year.