Navajo lawmakers have rejected a settlement that recognizes the tribe's rights to water from the Little Colorado River basin.
The Tribal Council voted 15-6 against the settlement Thursday during a special session in Window Rock.
U.S. Sen. Jon Kyl had introduced legislation to approve the settlement, but it needed the blessing of the Navajo and Hopi tribes to move forward. Kyl has said the settlement would address water needs on the reservations and provide certainty of the water supply for off-reservation communities.
Under the settlement, the tribes would have waived further claims to the river basin if the federal government funded groundwater delivery projects.
Hopi lawmakers had approved the settlement but rejected Kyl's legislation.
The Navajos disapproval likely sends the tribes back to court to quantify water rights.