With 11 atmospheric rivers pounding the state since late December, California has had an unusually wet winter. Tuesday’s anticipated arrival of the twelfth such storm raises the possibility of additional flooding, landslides, and road closures.
Atmospheric rivers are massive airborne currents of dense moisture that are funnelled over land to fall as heavy rain and snowstorms after travelling hundreds of miles from the Pacific. Below are some short- and long-term effects of these storms.
For the first time since 2020, according to the University of Nebraska-U.S. Lincoln’s Drought Monitor, California is largely drought-free, with only the driest areas experiencing “severe” or “moderate” dryness.
A few months ago, the state was depicted in big chunks on a color-coded map produced by the monitor, which collaborates with the National Oceanic and Atmospheric Administration and the U.S. Department of Agriculture, showing “severe” or “exceptional” drought conditions. The state’s Central Valley agricultural plains were home to several of the driest regions.
The West and California, according to experts, have not been spared from longer-term conditions that, between 2000 and 2021, produced the region’s driest 22-year stretch in 12 centuries.
Claim you’re broke, advised hydrologist Jay Famiglietti of Arizona State University. Even if someone offers you a $100 check and you have enough money for a day, you are still in financial trouble.
According to Thomas Harter of the University of California at Davis, there was a sustainable ratio of roughly 10 rainy years and 10 dry years during any typical 20-year span of the 20th century. According to Harter, a sustainable ratio of around 10 rainy years and 10 dry years occurred during any typical 20-year span of the 20th century. But only nine of the past 25 years have been wet, while the other 16 have been dry, thus the state needs seven more wet years to recover. Furthermore, climate change predicts that future years will likely be warmer, which will exacerbate the current dry conditions.
Without any consideration for replenishing subsurface aquifers, California’s 20th-century infrastructure was built to pump water from north to south for irrigation, human consumption, and flood protection. Stormwater runoff consequently primarily drains into the ocean.
According to the state’s Water Supply Strategy, which was published last year, there should be adequate water storage space to hold up to 4 million acre-feet (4.9 billion cubic metres), or enough water for 8 million households in the 40 million-person state. The majority of that would be kept in subterranean or groundwater storage. But, the strategy is brand-new, as is California’s approach to coping with drought in the face of climate change. Despite the fact that the state just allocated $8.7 billion for drought resilience, much of it for stormwater capture,
Isaac Sanchez, a battalion chief for the California Department of Forestry and Fire Protection, stated that the abundant rainfall this winter has already caused significant growth in the grasses and scrub that will dry out by summer, creating a larger, thicker fuel bank for wildfires (CalFire).
Nonetheless, Ed Clark, director of NOAA’s National Water Center, noted that larger shrubs and trees retain moisture, making them less likely to burn as quickly as they might when entirely dried by drought.
The dangers near burn scars from previous wildfires may be exacerbated by the heavy rains. Mudslides can occur on the depleted soil.
The atmospheric rivers brought comparatively little rain to the overused Colorado River basin, which drains seven Western states and a portion of Mexico. Although there was a lot of snow in the mountains, the river’s long-term condition is still very bad.
The 101-year-old Colorado River Compact, which divides the river’s water rights among seven states, includes Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming. Several states are proposing to renegotiate the deal with the federal government in exchange for a 15%–30% reduction in river exploitation.
Despite the brief reprieve, analysts said California, which receives the most water from the Colorado River, is unlikely to trade away its senior rights simply because its reservoirs are currently fairly full. Federal action might be necessary to reduce Colorado River water use.
The snowfall at least prevented the two largest reservoirs in the country, Lake Mead and Lake Powell, which are fed by the Colorado River, from falling to “dead pool” levels, which is the point at which a dam can no longer send water upstream or generate hydroelectric power.