Work by Bloor Homes is set to get under way to build more than 300 new properties to land to the west of Station Road, Newport, along with a 70-unit extra care facility, built by Keon Homes.
Preparations for work on the site are now getting started with mesh fencing put up.
But Bloor Homes has revealed, in correspondence with local councils, that some fencing had been targeted by vandals and have warned that, if necessary, CCTV will be installed.
A spokesperson for Bloor Homes said: “We like to keep town and parish councils informed of the progress of the site and contacted them to let them know we would be erecting Heras (mesh) fencing in preparation of the first phase of build.
"However, when a contractor arrived at the site on Monday, June 13, some fencing panels had been broken or taken down and some wooden posts had been burnt.
"We are now considering other measures to protect the site including CCTV, but hope that it will not come to that.”
Newport councillor Peter Scott said: "It's disgraceful people are trying to damage fencing along there.
"All that will happen is we will probably lose the opportunity of walking through because they will close off the public right of way."
Councillor Scott urged people to report any incidents of vandalism, adding: "It's wrong to walk by and pretend it's nothing to do with you. People need to report these incidents and highlight the issues."
Bloor Homes are aiming for the first residents to move in by the spring 2023 and hope for the entire development to be complete by the winter of 2027. As a condition of the plans, Bloor will pay £3 million towards local infrastructure.
The spokesperson added: “This is a new development of 2, 3, 4 and 5 bedrooms homes which will bring both new houses and bungalows to the area, creating new homes for everyone from first time buyers to families.
“In addition there will be 60 affordable new homes built here as well as extra care flats available as affordable rented homes.
“We are also contributing £3 million in infrastructure and services, ranging from highway improvements, additional school capacity, a public open space and multi-use games area.”
The development has been years in the making, but detailed proposals for the land were only approved in January this year. Public open space and a multi-use games area also form part of the scheme, as well as the retention of the Hutchison Way, which was set to be diverted under previous plans for the site.