The two companies are committing time and money to sprucing up the memorial in Main Road, Otterbourne, ahead of next year's 100th anniversary of the start of the First World War.
Mr Brine, MP for Winchester and Chandler's Ford, saw the first stage of the work – a new kerb which has been installed around the perimeter of the memorial.
Steve Brine said: "Otterbourne is a thriving community so I am not surprised they're making such an effort to mark next year's centenary.
"In many ways 2014 will be a terribly sad commemoration but the spruce up being given to war memorials across our country, including here in Otterbourne, is something really positive. I look forward to going back to see the finished product."
The next stage of the work will involve cleaning the memorial and improving planting around the site.
Terry Revell, Southern Water's archivist, has lived in the village since 1983 and is leading the restoration work. As well as organising Southern Water and Clancy Docwra's involvement, he has set up a fund for the memorial which raised £2,000 from the community and a further £1,000 from the parish council.
Terry said: "War memorials are a mark of respect for those who gave their lives and it is only right that they are properly maintained and preserved.
"These improvements will enable future generations to pay their respects and I'm pleased that we have been able to do this with the support of Southern Water and Clancy Docwra."
Clancy Docwra's Steve Maffey said: "This was a great way for us to help support the community in which we are based and to show respect for those who gave their lives to defend it."
Pictured; from left to right, front row, James Action, Poppy appeals Co-ordinator for the Village, Dick Oldham, Veteran and ex-parish council chair, Terry Revell, Company Archivist at Southern Water and veteran, with Steve Brine. Second row, Steve Maffey, Manager from Clancy Docwra and Kevin Buck, Charities Co-ordinator for Southern Water. Back Row, Will Jones, Chair of Otterbourne Parish Council