A £30m upgrade to services in the Borders has been unveiled by Scottish Water.
It will improve treatment processes and deliver a "more resilient supply" to more than 20,000 households and businesses.
Among the towns which will benefit are Selkirk, Galashiels, Melrose, Lauder, Fountainhall and Newtown St Boswells.
MSP Christine Grahame said it was a "significant investment" which could bring "long-lasting" benefits.
The work will see a new seven mile (11km) pipeline built between Selkirk and Galashiels, a new storage tank constructed south of Selkirk, new treatment processes and the turning off of a treatment works in Galashiels.
The work will take place in phases over the next two years.
Mark Dickson, Scottish Water's director of capital investment, said: "This work to improve the water supply for the Selkirk and Galashiels area of the Scottish Borders will ensure we can continue to supply high quality water in the area long into the future.
"This project will enable us to provide a better, more resilient service than ever before."
The work will require some traffic management on the A7 "for a short period".
Ms Grahame, who represents Midlothian South, Tweeddale and Lauderdale, said: "I am pleased to see Scottish Water's announcement of an upgrade to the water services in the Borders.
"This is a significant investment which will bring long-lasting benefits to my constituents - including a better quality of water, greater supply capacity, and environmental benefits.
"I look forward to seeing the project develop over the coming years."
Fellow MSP Rachael Hamilton, who represents Ettrick, Roxburgh and Berwickshire, said it was "fantastic news".
"Not only does it deliver improvements in terms of filtration, but also for the environment," she said.
"It is vitally important that we not only have a sustainable and robust water supply and treatment system, but also one that is appropriate for our water courses and rivers."