Climate, for one, is a major culprit. With California experiencing warmer fall and winter temperatures and less rain, snowpack levels are 5% less than what is considered normal. However, when rain does occur, with no significant way to collect that water and reuse it, about 80% of rainfall gets dumped into the ocean.
This represents a significant issue regarding infrastructure. At one time, the Los Angeles River used to be a main source of the city’s water; however, in 1940 the city was concerned about flooding and needed a way to properly drain excess water. The river was restructured as a drainage system; water that was once useable began to be diverted into the ocean and the city lost a source of its drinking water.
“Water has always flowed into the ocean, but what we’re realizing now is that we need to capture it” says Kelly Sanders, Assistant Professor at the USC Viterbi Sonny Astani Department of Civil and Environmental Engineering.
Another reason that our sources are running low is due to water leaks and evaporation in the water transport system. When water moves from the Colorado River or the Sierras, through an aqueduct to Southern California, water can leak out of the aqueduct into the ground or is simply evaporated. A significant amount of water can be lost in the water delivery systems. In late 2015, the city of Los Angeles implemented “Shade Balls” to its reservoirs to assist in controlling water quality as well as save 300 million gallons of water per year from evaporation.
A large residential population has also stressed the water supply.
“More people means that there are more demands, at the same time that factors such as drought and higher temperatures have resulted in less supply” says Sanders.
Droughts are cyclical. Southern California last experienced one in 1985 that lasted for six years, while others in the distant past have lasted much longer. Sanders says “the current drought situation us one of the driest and hottest season, it could end soon or it could last a long time.”
Therefore, cities, states, and citizens should not look to a short‐term solution, but should think long-term conservation. Understanding where our water comes from and where it is going is an important step in understanding how to survive drought years.