How Do Climate Change and Population Growth Affect Our Water Supply?

While San Diego has a variety of climates, it is overall fairly arid and cannot sustain a significant human population without importing massive quantities of water from other regions. With a population of just over 3 million, San Diego must import approximately 70 percent of its water, mostly from the Colorado River. Our demands for water, however, already exceed the Colorado River’s supply. Compounding matters, anticipated climate change and population growth will combine to exacerbate San Diego’s water supply issues.

Climate Change: Climate change is expected to reduce the Colorado River’s water flow and could have a drastic impact on the supply to San Diego. A study performed by the Department of the Interior’s Bureau of Reclamation projects a nine percent decrease in the River’s water flow over the next 50 years, and anticipates that 40 percent of the time, the region will be subject to droughts spanning five or more years. According to the California Climate Change Center, the availability of water imports from the River to San Diego may decline by 20 percent, with models estimating the actual decline will be anywhere from 6 to 45 percent.

Population Growth: If current population growth trends continue, another 1.5 million people will reside in the county by 2050, bringing the total number of residents to 4.5 million. Increasing humans means increasing demand for water. By 2050, desired water use is likely to exceed current demand by 37 percent increase.

The increasing demand for water, combined with the decreasing supply, makes conservation more important now than ever. There is a lot you can do, including utilizing low-flow showerheads and ultra-low-flush toilets, remembering to turn the water off while brushing your teeth and reducing shower times, or turning the shower off while you suds up. Outdoors, use a pool cover to reduce evaporation, water your lawn in the hours between sunset and dawn when the water is less likely to evaporate and, importantly, make sure you’re watering your lawn instead of the sidewalk or driveway. These are just a few of the ways that you can help conserve water. Click here for more.

Additionally, the City of San Diego provides certain rebates and incentives to residents who implement water-efficient landscaping or rainwater harvesting. Through their program, you can not only save money, but you can also become part of the effort to reduce San Diego’s water demands to sustainable levels.