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, but now believe that court action is the only resort left.

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 been  made with the Snuneymuxw, which considers the land in dispute to be in their  traditional territory. Ruttan said he's not sure if the Snuneymuxw have a strong  legal case.

Harmac president Levi Sampson said the mill has talked with the Snuneymuxw,  but it is 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 growing demand.