The company was shortlisted as one of two international firms bidding to build the water storage scheme.
The other is a joint venture between a Spanish infrastructure company Obrascon Huarte Lain, and New Zealand company Hawkins. The winning bid is expected to be declared in October.
Bouygues partnered with the Napier branch of Opus International Consultants and MWH. Staff from Bouygues' international sites, French nationals, arrived in Hawke's Bay in April and are based at the Opus Ahuriri office.
"So we've got staff which we've located here, they work here and live here, and are being welcomed by the community. I would say the company would have put about $4 million back into the community by having its staff in Hawke's Bay."
Mr Tilley said the company operated on four principles and he had to convince his superiors building the dam would achieve all four. It would have to be a project of environmental and sustainable construction, be able to bring on board customers and partners, show commitment to local and community support and achieve respect and development of employees.
Connecting with the community was an important part of the bid but Mr Tilley said he had resisted pressure from the company's marketing team to launch a major public relations project in the Bay.
"I've wanted to do that myself, to meet with people face-to-face and talk with them. And we've done many presentations to groups over the past couple of months to speak about the dam and our bid.
"I think that's the key benefit we've got, the fact we have staff based here and that we're meeting with people all of the time."
One of the groups he had met with was the regional council's Maori committee to speak about employment opportunities during the dam's construction.
"They already knew a lot about the project and the possibilities for their people and it's easy to see how important it could be to their people."
He had also met with contractors' representatives and other community groups. He estimated the company could employ 100 people or more during the construction of the dam.
"We also have a lot of Kiwis, mainly Maori, working on one of our sites in Western Australia and they are asking to come over to Hawke's Bay to work on the dam if we win the bid.
"There is a lot of interest but we've made it clear that if they want to work on this project, they will have to come here to Hawke's Bay to live."