学习一下。20% vs.30% vs.50%

The main sources of water for Southern California are the Colorado River, the Northern Sierra, and local supplies: 

 

• Colorado River: About 20% of Southern California's water comes from the Colorado River, which is brought to the region through the Colorado River Aqueduct.
• Northern Sierra: About 30% of Southern California's water comes from the Northern Sierra.
• Local supplies: The remaining 50% of Southern California's water comes from local supplies, including groundwater, recycled water, desalination, and the city of Los Angeles' eastern Sierra deliveries.

Here are some other details about water sources in Southern California:

• Groundwater: Wells are dug into aquifers to access groundwater, which can then be pumped to the surface. 
   
• Recycled water: Wastewater from homes and businesses is treated and recycled. 
   
• Stormwater capture: Projects are being developed to capture stormwater and recharge groundwater. 
   
• Climate change: Climate change and environmental enhancements are reducing the water supply. 
   
• Drought: Low rainfall or light snowfall can lead to drought.