The Snuneymuxw First Nation is preparing court action against the City of Nanaimo and the Harmac pulp mill over a water-sharing agreement between the city and the mill that is expected to be signed soon.

Snuneymuxw Chief Doug White said Harmac has been infringing on the First Nation's water rights for years and he's concerned an agreement is expected without the involvement and consent of the Snuneymuxw.

White said the Snuneymuxw have been trying to find a way to satisfy all sides on the issue, but now feel that court action is the only resort left to them.

Snuneymuxw First Nation Chief Doug White.

Harmac has been in discussions for years with the city over the potential of sharing water from Harmac's dam at Fourth Lake, or building a second one, as the city's water needs increase.

Nanaimo Mayor John Ruttan said he's "frustrated" that no agreement has yet been made with the Snuneymuxw, which considers the land in dispute to be in their traditional territory. Ruttan said he's not sure at this time if the Snuneymuxw have a strong legal case.

Harmac president Levi Sampson said the mill has had some discussions with the Snuneymuxw over the issue, but it's ultimately up to the city and the First Nation to come to an agreement.

"It's unfortunate that it has come to this, but we think it's time to educate our local government and industry about treaty rights," White said Thursday.

"In fact, we have significant legal rights around the water supply issue and we intend to stop this agreement from happening. The fact that the city and Harmac would consider moving forward with a water-sharing agreement without the Snuneymuxw shows a pattern if disrespect that we want stopped."

The city's water strategy indicates that Nanaimo will need an additional 20 million cubic metres of water to meet the growing demand from a population that is expected to reach 100,000 by 2020. Ruttan said White has made it clear he doesn't want a new dam built on traditional Snuneymuxw territory.