February 22, 2023 548 PM
Drought in the western U.S.
2023 started off with a bang for the drought-stricken West. The region was in the throes of what scientists are calling the driest period in 1,200 years when a series of major storms blew in off the Pacific starting just after Christmas. The storms, also known as a “Pineapple Express,” formed so-called atmospheric rivers over much of California and neighboring states, causing widespread flooding, refilling reservoirs, and killing at least 20 people.
According to the National Oceanic and Atmospheric Administration, atmospheric rivers are “relatively long, narrow regions in the atmosphere … that transport … an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi River.” When these “rivers in the sky” make landfall, they often “release this water vapor in the form of rain or snow.” While atmospheric rivers are a relatively common phenomenon, the bomb cyclone that hit the West Coast dropped an average of 11 inches or 32 trillion gallons across the region over a period of three weeks.
While a single season of heavy rainfall may be enough to refill California’s biggest reservoirs, the news website CalMatters warns that “the same cannot be said of the Colorado River’s huge reservoirs.” Seven states and about 40 million people rely on water from two reservoirs, Lake Mead and Lake Powell, both of which have been in decline for decades. The two impounded lakes hold 50 million acre-feet combined and “even several wet winters in a row will not come close to refilling them.”
Part of the problem is that atmospheric rivers often fall too fast over a short period. This makes it difficult to store that much water. The issue has several facets: 1) A lot of the rain falls downstream from the reservoirs and is not captured, and 2) Capturing such a large volume of rain early in the year poses a risk of flooding later on. Despite severe and ongoing drought conditions, many reservoirs in the West actually opened their outflow gates during the recent winter storms to prevent overflow.
Another challenge involves the built environment, which is designed to direct rainfall into storm drains and out to sea before it can be captured to augment water supplies. According to CalMatters, “The recent storms have highlighted the need to design and build stormwater systems capable of capturing runoff … Even sinking urban runoff into the ground via rain gardens and bioswales is a better option than letting it escape to sea.”
One of the bright spots of the recent winter storms has been their incredible boost to the mountain snowpack that supplies a significant amount of California’s water. The current snowpack is outpacing the state’s wettest season on record, according to state water officials. And there are still a couple of months to go before the winter snow season is over.
Much like children on a long road trip, a lot of people throughout the western U.S. are asking, “Is the drought over yet?” The answer is maddeningly nebulous because it’s so difficult to determine when a drought begins and ends. In the case of California’s drought, the reports are mixed. While some experts refer to the Drought of 2013-2016, as though it had a clear beginning and end, others think that the drought of the past few years never really stopped. Based on the data since the last major rainy season of 2006, only three of the past 16 years (2011, 2017 and 2019) have been notably wet in California. Many climate experts believe the predominant weather pattern in the western United States will involve ongoing drought conditions interrupted periodically by very wet interludes. According to Jeffrey Mount, senior fellow at the Public Policy Institute of California, “This might well be just another case of a wet year followed by a string of dry ones.”
The lesson for groundwater-dependent regions like the Big Bend is clear. We need to restore and enhance our existing watersheds, design our built environments to capture runoff, and create targeted natural infrastructure to hold the water where it falls and augment aquifer recharge as much as possible. The technologies already exist and funding from the State Revolving Funds could soon be on the way.
Trey Gerfers is a San Antonio native and serves as general manager of the Presidio County Underground Water Conservation District. He is also chairman of the Presidio County Water Infrastructure Steering Committee and president of the Marfa Parks and Recreation Board. Trey has lived in Marfa since 2013. He can be reached at [email protected].