De Beers will operate the Gahcho Kué project in which it holds 51% stake, while Mountain Province Diamonds holds the remaining share.
The mine will create around 700 jobs during construction phase and around 400 jobs on commencing operations.
The Type A Water License is yet to receive final approval from the Minister of Environment and Natural Resources (ENR) of the Government of the Northwest Territories (GNWT).
De Beers Canada CEO Tony Guthrie said: "This represents one of the final regulatory steps for the Gahcho Kué diamond mine and is the result of very hard work by the Project team over the past eight years with the Board, Regulatory agencies, Aboriginal parties, Communities and other Stakeholders.
"We will continue to develop the Project responsibly in keeping with the principles of sustainable development, including protection of the environment, and with respect for Aboriginal culture and traditions."
Mountain Province Diamonds CEO Patrick Evans said: "As the world’s largest and richest new diamond mine, Gahcho Kué will maintain Canada’s position as a leading diamond producer. Employment created by Gahcho Kué and revenues generated by the mine will contribute to growth and prosperity in the NWT."
