Home Articles Where Does Your Water Come From? Where Does Your Water Come From? Posted: Thursday, April 29, 2021 For the past 60 years, Mesa Water District (Mesa Water®) has provided 100% clean, safe, and reliable water to its customers. In the early days, Mesa Water relied completely on imported water from Northern California and the Colorado River Basin. Today, groundwater supplies are Mesa Water’s primary source of drinking water. But where exactly does our water come from? Groundwater or well water is pumped from the Orange County groundwater basin via Mesa Water’s seven wells. The basin is replenished by water from both the Santa Ana River and imported water purchased from the Metropolitan Water District of Southern California. Mesa Water‘s groundwater is disinfected with chloramines before it enters the distribution system. Additionally, Mesa Water supplements its groundwater with water from the Mesa Water Reliability Facility (MWRF). Source water for the MWRF is pulled from deep below ground, with an amber tint from ancient redwoods. The redwoods, which grew alongside the coast of Orange County over 100,000 years ago, have long decayed over time, giving the water its amber-colored tint. Mesa Water uses state-of-the-art nanofiltration technology at the MWRF to remove the tint and adds the clear, purified water to its water supply. While Mesa Water is not dependent on outside sources, imported water from Northern California and the Colorado River is accessible, if needed.