Your water: From source to tap

The Santa Ana Watershed Project Authority (SAWPA) and our water agency partners ensure that accessing safe, reliable H2O is as easy as a turn of the tap. High-quality, potable water (drinking water) is always available to your home or business at any time you need it.   

Whether you are turning on your shower for a morning wake-up, setting up the sprinkler to water your garden on a sizzling summer afternoon or guzzling a cold glass of H2O after a challenging workout, water is always there for you. While accessing water is a breeze, your water’s journey from source to tap is quite complex. Before it reaches your pipes, your water travels through a labyrinth of treatment and delivery infrastructure. Let’s explore how! 

Your water is sourced.  

Imported Water 

Water experts and planners in the 1960s saw an opportunity to provide the Golden State with water security for the future and an infrastructure project that would be the first of its kind in the United States according to the California Department of Water Resources. The State Water Project was born. The California State Water Project is a water storage and delivery system formed of dams, reservoirs, aqueducts, and power and pumping plants. The project supplies drinking water to more than 27 million Californians and irrigation to more than 750,000 acres of farmland.  

The State Water Project extends from Lake Oroville in Northern California all the way south to Riverside County. Water is pumped over 700 miles through pipelines, tunnels, canals and power plants to distribute water to agencies throughout California. Southern California also receives imported water from the Colorado River aqueduct that brings fresh water from parts of the states of Arizona, California, Colorado, New Mexico, Nevada, New Mexico, Utah and Wyoming.  

Local Water 

Water in Southern California is also sourced through groundwater. Groundwater is exactly what it sounds like, water from the underground. Groundwater is stored in aquifers and basins hundreds of feet beneath the surface we walk, drive and live on. SAWPA and our partner agencies know the supreme value of groundwater because it utilizes local water sources and reduces the demand for importing water from Northern California and the Colorado River. This process is more locally sustainable in the face of emergencies and less costly than purchasing water from far away.  

Your water is cleaned and treated.  

Water treatment supports public health and ensures that it is safe for use at your home and business. Treatment includes a four-part process.  

  1. Coagulation: The first process of water treatment involves some fancy terms: coagulation and flocculation. Coagulation is the process of adding chemicals with a positive charge to the water that neutralizes the negatively charged particles in the water. The positively charged chemicals neutralize and then bind with the particles. When the chemicals bind, they form larger particles called floc. 
  1. Sedimentation: The floc then begins to settle to the bottom of the tank in a process known as sedimentation. Sedimentation of these particles aid in the process of removing them and pushing the water on top to continue through the process of cleaning and treating the water.  
  1. Filtration: The clear water on top of the tank then passes through multi-layer filters and screens to remove dust, parasites, bacteria, viruses and chemicals. 
  1. Disinfection: Finally, the water is disinfected to kill any pathogens left in the water.  

Water is put to the test.  

Your water agency tests and treats water thousands of times per year to ensure it meets the highest water-quality standards in the world. Testing of your water is done on-site at operational facilities as well as in labs. The quality of your water is governed by the United States Environmental Protection Agency Safe Drinking Water Act, which requires all public water systems to notify customers annually regarding the quality of the water they receive. 

Water is delivered right to your faucet. 

Delivery time! Water delivery infrastructure allows for the water to show up right to your home or business. Your water agency pumps water from a reservoir which often sits on a hill or high point and pumping stations. Because of its heightened location, the reservoirs can use gravity to flow water through pipes to reach your tap. Pumping stations use engines and pressure to deliver water straight to you.