The seven Colorado River Basin states have been unable to agree on a deal to conserve the massive amount of water needed to keep reservoirs stable. But more than 30 tribal nations also have a legal claim to that embattled resource — including a dozen whose …The seven Colorado River Basin states have been unable to agree on a deal to conserve the massive amount of water needed to keep reservoirs stable. But more than 30 tribal nations also have a legal claim to that embattled resource — including a dozen whose …