PHOENIX (AP) — Arizona Gov. Doug Ducey signed legislation Wednesday that will provide $1.2 billion over three years to boost long-term water supplies for the desert state and implement conservation efforts that will see more immediate effects.

The legislation that was hammered out over months during the just-completed legislative session is viewed as the most significant since the state implemented a groundwater protection plan in 1980.

Climate change and a nearly 30-year drought forced the move, which comes as Arizona faces cutbacks in its Colorado River water supply and more loom. The Centra...