S. Army Corps of Engineers built the lake in the 1970s, but the state hasn't paid the federal government back for the lake's construction. The state must make a $5.2 million payment toward its debt by July 1. The tribes confirmed Thursday that they have offered to make that payment. "Using the debt owed by the state to the federal government as an excuse to make a deal that ignores the two tribes' historic water rights and the environmental and economic interests of all of southeastern Oklahoma just doesn't make sense,” Choctaw Chief Gregory Pyle said. The tribes want a statewide water use study complete before any Sardis Lake water deal is approved. Oklahoma City wants to pipe the water from southeast Oklahoma to cities throughout central Oklahoma.