The mayor of Delta is concerned about the impact a landmark treaty with the Tsawwassen First Nation will have on her community.

The deal, which is the first urban treaty involving a First Nations band in the Lower Mainland, will be signed Friday at a ceremony on the reserve.

But Mayor Lois Jackson says some provisions in the agreement with the federal and provincial governments could be bad for Delta.

The treaty, reportedly worth $120 million, promises band members commercial fishing rights and hundreds of hectares of agricultural land.

"Delta cannot afford to lose one more acre of good agricultural land or we will have no agricultural component left in this community," Jackson said Thursday.

The deal will also allow the Tsawwassen band to convert some of that land into industrial use as part of an expansion of the Roberts Bank port terminal.

Members of the band will also receive a share of the Fraser River salmon fishery.

Dollars will flow outside reserve

John Burrows, an aboriginal rights lawyer with the University of Victoria, supports the treaty. He says the benefits of the deal will flow beyond the band's boundaries.

"As dollars come in to the Tsawwassen First Nation and they become players in the local economy, those dollars will not just circulate within their communities but will spill out into surrounding communities," Burrows said.

Premier Gordon Campbell is also turning aside concerns the Tsawwassen agreement will remove prime farmland from the agricultural land reserve.

He says the band deserves to have some land for development purposes and insists the treaties are balanced.

The chief of the Tsawwassen band has not yet addressed the controversy, but is expected to at the signing ceremony.

A second treaty is scheduled to be signed Saturday on Vancouver Island with the Maa-nulth First Nations from the Port Alberni area.