Drought Hits California – Again or Still? Some Facts to Ponder
A compilation from the City of Davis website and writer Michael Kluk
In October 2021, the Davis City Council reinforced the Governor’s call for a voluntary 15% reduction in water usage and adopted sprinkler irrigation watering restrictions as a preventive measure to assist the City in reducing water usage and to help meet the state-wide call for voluntary reductions. The watering restrictions only apply to sprinkler/spray irrigation and do not apply to other methods of irrigation such as drip systems and hand-watering. Alongside the City’s permanent mandatory water-use restrictions, there are now additional state water waste prohibitions (for the duration of the state-declared drought emergency).
The Cool Davis Coalition Quarterly Meeting addressed the lack of water, that we find ourselves experiencing, again. The most recent Cool Davis Coalition Quarterly Meeting (“Building a Drought Resilient Community”) included presentations by City of Davis Conservation Coordinator Dawn Calciano and Don Shor of Redwood Barn Nursery and Tree Davis. (Check out a video of the presentations here: https://youtu.be/B_vf5VU1l94). The most recent monthly Climate Compact meeting hosted by Don Saylor and John Mott-Smith was also focused on water topics, in particular.
Sprinkler Irrigation Restrictions
Summaries of the three big water supply stories so far this drought cycle follow below:
Southern Californians Face Water Restrictions with More to Come
Starting June 1st, many areas of Southern California will be limited to watering outdoor only one day per week. Currently included are the Westside of Los Angeles, the San Fernando Valley, a large swath of Ventura County, sections of the San Gabriel Valley and southwestern San Bernardino County. Six million residents are affected. If conditions do not improve by September, a total restriction of outdoor watering has been authorized and other areas may come under restrictions. One major exception is that hand watering of trees is allowed, given their major contribution to the environment by providing shade, habitat, and sequestering carbon.
Sources
https://abc7.com/southern-california-water-restrictions-drought-mwd/11798774/
Lake Mead and Lake Powell at Lowest Level Since Construction of the Hoover and Glen Canyon Dams
Lake Mead and Lake Powell provide water and power to more than 40 million people. Water levels in both lakes have dropped to historic lows due to the most severe mega drought in 1,200 years that started in 2000 and is projected to continue until at least 2030. Climate change is at least partially responsible. Both lakes are approaching a level at which they will no longer be able to produce power. At Lake Mead, the water level has dropped below the highest outlet, which cannot, therefore, be used to drain the lake.
Sources
https://www.cnn.com/2022/04/27/us/water-intake-exposed-lake-mead-drought-climate/index.html
California’s Drought Accelerated Use of Groundwater Is Unsustainable
We don’t see it and so don’t think about it often, but groundwater below the surface is a major source of California’s water supply. During normal years, groundwater provides about 40% of water supply, during a drought closer to 60%, much of it going to agriculture. As climate change makes California’s boom and bust precipitation cycles more extreme and less falls as snow, groundwater will become more important.
Even the amount of water pumped during the “good” years is unsustainable. Both agricultural and residential wells are going dry, often because a newer, deeper well is reducing the groundwater level. Satellite “gravity” surveys that determine groundwater volume found that California’s total decreased by 20 cubic kilometers between 2003 and 2010. (A cubic kilometer of water is 264.2 billion gallons.) That led to a 2014 law, currently being phased in, that requires monitoring and regulation of groundwater. Even so, it only mandates that efforts be made to maintain current levels, with exceptions for drought years, and it need not be fully implemented until 2040.
Sources
https://calmatters.org/environment/2021/08/california-groundwater-dry/
https://www.ppic.org/publication/groundwater-in-california/
