Washington state is weighing controversial proposal to breach four lower dams to boost recovery of threatened salmon populations, with potential cost in billions to replace their power generation.

Four Snake River dams produce energy, enable commodity barging and provide reservoirs for irrigation.

A concept floated by Republican Mike Simpson, a U.S. congressman from Idaho, holds the potential to loosen the intractable logjam that has persisted for years among lawmakers, community members and federal officials to find a way to save the dwindling salmon population in the Columbia River Basin before it is too late.