Completed in 1967, the San Luis Reservoir is the largest off-stream reservoir in the World and its shrinking. In the summer of 2013, it was at 15% capacity, the lowest level since 1989 when California was in the midst of 5 year drought. During such low levels, water supply to Santa Clara County and San Benito County is at risk because high temperatures combined with declining water levels foster growth of an algae layer, as much as 35 feet thick on the reservoir’s surface. Algae like this can be extremely difficult to treat. San Luis is an example of California’s historical problem of fresh water supply and the trend is worsening. Less snowfall and rain is predicted in the Sierra Nevada whilst population is set to continue to increase within the state. Adapting California’s water management in response to climate change presents a significant challenge.
All Images Copyright Jim Johnston 2017.