With more than two-thirds of Washington state experiencing abnormal dry conditions and more than half of the state experiencing moderate drought, Governor Jay Inslee on Friday declared a statewide drought emergency.

“We are really starting to feel the pain from this snowpack drought,” Inslee said. “Impacts are already severe in several areas of the state. Difficult decisions are being made about what crops get priority water and how best to save fish.”

According to the Washington state department of agriculture, about $1.2bn of crops could be lost as a result of the drought this year.

“The drought is unlike any we’ve ever experienced,” said Maia Bellon, director of the state department of ecology. “Rain amounts have been normal but snow has been scarce. And we’re watching what little snow we have quickly disappear.”

Bellon’s department has requested $9.5m in drought relief funds from the state legislature.

The 21st-century projections make the [previous] mega-droughts seem like quaint walks through the garden of Eden Climate scientist Jason Smerdon

At the beginning of the month, the Natural Resources Conservation Service found that of 98 snow sites measured in Washington, 66 were snow-free, 11 for the first time ever. According to Inslee’s office, snowpack in Washington’s mountains has dropped to just 16% of normal levels.

In California, snow on the mountains has fallen to 12% of average levels, from 28% last year. Snowmelt normally keeps the rivers running – in April, the US Geological Survey found that 78% of streams in Washington state were running below normal. As a result, the state’s department of natural resources expects more early-season and higher-elevation wildfires.

“We have some tough, challenging months ahead of us,” Inslee said. “We’re ready to bring support and relief to the hardest hit areas of the state. We’re going to do everything we can to get through this.”

About 2.47 million people living in Washington are affected by the drought, according to the information released on Tuesday by the US Drought Monitor. A year ago, 55.74% of the state was abnormally dry and 34.66% of the state experienced moderate drought. This year, 67.51% of the state is abnormally dry and 51.82% is experiencing moderate drought.

The droughts in California and Washington are only the beginning, according to a study written by the scientists at the Columbia University’s Lamont-Doherty Earth Observatory. They predict that the US south-west and the Great Plains will face decade-long droughts far worse than any experienced over the last 1,000 years, because of climate change.

“The 21st-century projections make the [previous] mega-droughts seem like quaint walks through the garden of Eden,” said climate scientist Jason Smerdon, a co-author of the study.

“We haven’t seen this kind of prolonged drought even certainly in modern US history. What this study has shown is the likelihood that multi-decadal events comprising year after year after year of extreme dry events could be something in our future.”