Wednesday, June 30, 2021

Megadrought

I went in an airplane for the first time in 18 months. I flew over the Great Salt Lake—what was left of it. It looked like the Aral Sea. Antelope Island was connected to the mainland on three sides. The antelope were halfway to Saratoga Springs. There was hay growing in Farmington Bay. Foxes and coyotes were nearly across the new land bridge to Gunnison Island to visit the 10,000 pelicans they insisted were kin.

The Great Salt Lake is about to drop below the all-time low because of agricultural water diversions and climate change.

The bottom of the Great Basin. This is the place that floods when God sends the snow. This is the place that dries up when we divert the rivers.

Some of us get lulled into thinking that this drought is just more of the same. Some of us are wrong. The current conditions the Southwest is experiencing are called a megadrought—a dry period that lasts more than 10 years. This megadrought has been going on for so long that if you were born in the 90s or later, your entire life may have unfolded during the big dry.

Evaporation ponds next to the Great Salt Lake during a more normal year.

Lake Powell is so low the dock just broke loose. At the Utah Water Task Force meeting, I learned that reservoirs in the Weber River usually have 80,000 acre feet of water storage. This year, they hold 2,700. Now that humans dominate the global water cycle, this story is stuck on repeat almost everywhere on Earth (Abbott et al., 2019a). 

I think it's really important to provide some context to this drought. Tree rings show that we are in the driest 20-year period since trees started keeping records some 2,000 years ago. I think it’s even more important to identify what is causing these conditions. Our megadrought is directly a consequence of human-caused climate change. This isn't a natural disaster. This is an unnatural consequence of our overuse of fossil fuels. We have supercharged the summers, disrupted the wet winds from the Pacific, and made snow and rain less reliable. I don't blame climate change in a generic way, there is solid science on this megadrought specifically (Williams et al., 2020). These conditions have also caused a doubling of annual wildfire extent across the West, setting the stage for megafires that burn whole valleys and mountainsides. 

Governor Cox asks Utahns to join him in prayer to break the drought.

I believe in the power of prayer, but how does God feel when we pray for our actions to have no consequences? To solve this part of the megadrought, we need to dramatically decrease fossil fuel combustion so the climate can get back to normal. The best way individuals can do that is by pressuring their elected officials to stop climate change, changing their transportation to bikes and public transport, and eating a plant-based diet (cartoon Ben says it best). Doing these things would leave us healthier, wealthier, and much more secure (check out this recent post on the ongoing global decarbonization).

The natural response to scarcity is to try to increase supply. We build pipelines, dams, and canals so there is more water available when we want it. This has been the response of Utah as a state. I hear from state legislators all the time that we should build more dams, and the state just created a new River Authority that is going to fight with our neighbors in Nevada, Arizona, and Colorado for more water. They'll be fighting over water that doesn’t exist.

The problem with this supply-side approach is that demand can always grow faster than supply (Abbott et al., 2019, Ellison et. al., 2012). Demand is basically limitless. Building more dams won't help in any way if the rain and snow never come. Suing California won't help if there is no water in the river or aquifer to take.

We need to manage our demand as individuals and as a society to live within our means. Much of Utah, including where I live, is in the Great Basin. This is a huge internally draining part of the Earth with no rivers to the ocean. Areas like ours are extremely sensitive to climate change and human water use. Consequently, endorheic basins all over the world are experiencing hydrological collapse (Wurtsbaugh et al., 2017). We need to recognize that we have limited water resources and change our behavior to live within those limits.

So what are we using our water for? More than 80% of Utah's water use is agricultural. Some of this water use is totally justified and important, such as the water used to grow food for people. I love Utah cherries, watermelon, corn, and essential oils. Unfortunately, the production of Utah fruits has dropped by half since the mid 80s. Over the same time period, alfalfa production has increased by 300,000 tons per year (USDA). Today, 70% of our agricultural water goes to grow alfalfa, most of which is exported to China to feed livestock. Does it really make sense to subsidize an economically marginal activity that doesn't increase our food and water security? If you think it doesn't, I invite you to stop eating meat and talk with your legislators about supporting water reform.

Of the remaining non-agricultural use, most is outdoor water use. There are plenty of beautiful native plants that grow happily without irrigation. However, for some reason we have decided that we need turfgrass in front of every house and building, even though this non-native species needs huge amounts of water and fertilizer. As individuals and as a part of various corporate, educational, city, and state communities, we need to change the way we landscape.

Outdoor water use is up the bulk of domestic water use. In light of the severe and extended drought, we let our lawn go dormant this year.

There is also an economic solution to this problem: let the price of water increase. Currently we heavily subsidize water, paying one of the lowest prices per gallon of anywhere in the U.S (Utah Rivers Council). If the price reflected the cost, we would all waste a lot less water.

There are also problems with water law that cause a lot of waste. Under current water law, if you don't use your water rights, you lose them. That means there is a huge disincentive to conserve. For example, Provo is considering piping water from the Provo River and releasing it up Rock Canyon. They could simply let Rock Canyon flow, but they have water rights in the Provo River that they need to find a beneficial use for. I wonder if the river could use the water beneficially. There are thousands of counterintuitive inefficiencies like this going on every day in our state that we need to resolve. We should have water law that encourages conservation and strategic agriculture while ensuring the health of our ecosystems. Call your legislators or provide feedback here to encourage scaling up the water banking pilot program.

I grew up in Utah, and I love this place with all my heart. We need to change our laws, policies, and behaviors to stop climate change and water waste in our beautiful state. This will make a better world for all of us and make us much more prepared for the next drought. Or for this drought, if it lasts another twenty years.