For approximately a hundred years, our civilization has developed approaches to speed water away. Increasingly frequent and severe floods and droughts lead to higher levees, bigger drains, and longer aqueducts. We are beginning to learn, however, that increasing concrete infrastructure to control water is exacerbating the problem.
Erica Gies’s new book, Water Always Wins, focuses on the slow movement of water, essentially nature’s way, to absorb floods, store water for droughts, and feed natural systems. California is adopting policies and laws to slow water movement in two ways in order to recharge our underground basins.
The first approach directs swollen rivers during periods of heavy precipitation into orchards and fields with permeable soils to slowly seep into aquifers. Since 65-80 percent of the Central Valley has clay soils, selecting only areas with permeable soil is critical for percolation and avoiding harm to crops and trees. California’s Central Valley, and most specifically the San Joaquin Valley, has the most depleted groundwater basins. In some areas, over-pumping and heavy use of groundwater have caused the land to sink by several meters. In 2014, the state legislature enacted the Sustainable Groundwater Management Act (SGMA). It requires farmers to treat aquifers like bank accounts, clamping down on overdrafts but allowing those who deposit water into them to make bigger withdrawals later. There are now actual groundwater banks with formal accounting systems to keep track of balances.