(CNN)Vast swaths of the West remain in a historic and unrelenting drought, the worst in the region in at least 20 years.
Drought conditions as of Thursday expanded and worsened in the West, especially in the Pacific Northwest, after another week of hot and dry weather, according to the US Drought Monitor.
Across the US, the drought has nearly doubled in size from this time last year. Around 25% of the country was in drought conditions in July 2020; as of this week, nearly half is in drought.
In addition to mandatory water restrictions already in place, even stricter cuts are looming amid the drought in some states as water levels plummet along the Colorado River.
Climate change is playing a key role in these compounding crises: Drought and extreme heat are fueling wildfires; reduced snowpack and the lack of substantial precipitation are exacerbating water demands for millions of people, as well as agriculture, ecosystems and deteriorating infrastructure.
Current drought
More than 93% of the West is in drought, the highest on record, with nearly 60% in ‘extreme’ or ‘exceptional’ drought, the two most severe categories. There are five states completely in drought conditions; California, Oregon, Nevada, Utah and North Dakota.
Exceptional drought in Oregon expanded, according to the US Drought Monitor, which said the state’s current conditions are among the driest since the late 1800s. In Washington, “rangeland and pasture conditions are far worse this year when compared to all other years this century.”
The Big Lost River in Idaho “is almost out of storage,” the Drought Monitor wrote, and there is “significant agricultural impacts to the state, including crop loss, a lack of forage, and animal deaths.”
As the planet warms, drought and extreme heat will also fuel deadly wildfires. Multiple studies have linked rising carbon dioxide emissions and high temperatures to increased acreage of burning across the West, particularly in California.
Rainfall outlook
The West experienced extremely low rain and snowfall over the past year, compounded by drastically high temperatures. Less rain and increasing heat waves have led directly to drought conditions and water shortages.
As climate change accelerates and winter temperatures increase, snowfall will decrease. High-elevation snowpack serves as a natural reservoir that eases drought, storing water through the winter months and slowly releasing it through the spring melting season.
Stream and river flow
Streamflow, a measure of how much water is carried by rivers and streams, is another significant indicator of drought and its impact.
As drought conditions have worsened in 2021, hundreds of stream and river locations are experiencing below-average flow. More than 50 percent of the western monitoring stations reported lighter-than-usual flows. Fishing restrictions have also been put in place on many rivers in Montana due to low flows and warm waters.
Changes in streamflow affect the water supply for our own municipal use, crop irrigation and power generation.
