Southern Nevada receives approximately 90% of its drinking water from the Colorado River, via Lake Mead. The river is one of the highest quality and cleanest water sources available in the world, originating as snow fall on the western slopes of the Colorado Rocky Mountains. The remaining 10% of our drinking water is derived from groundwater sources, or wells, located throughout the Las Vegas valley.
Because our water originates in the mountains and must travel through rocky substrate to form the Colorado River, there is a relatively higher concentration of naturally occurring minerals making the water "hard". Hardness in drinking water is caused by two minerals in the Colorado River system - calcium and magnesium. It is called "hardness" because the minerals make it "hard" to form a lather or suds for washing.
The City of Henderson treats and provides approximately 15% of the city's drinking water by our own Water Treatment Plant, with a capacity up to 15 million gallons per day. The other 85% is supplied by the Southern Nevada Water Authority, of which the City of Henderson is a member agency. The City is responsible for all drinking water distribution to Henderson residents and businesses.
Water from Lake Mead is treated by a state-of-the-art direct filtration treatment process, which includes pre-disinfection, coagulation, flocculation, filtration and post-disinfection. All treated water that enters the distribution system exceeds current drinking water standards as set forth in the Safe Drinking Water Act.
Because our source water is so clean to begin with, the treatment process is relatively simple. Small particles such as clay, silt and algae are first removed from the water, then the water filtered to further remove impurities. The filtered water is then disinfected by using ultraviolet (UV) light. UV light has been shown to be superior method for disinfection, without the use of chemicals. A small amount of chlorine is then added to maintain disinfection of the water as it travels through the distribution system to your tap.
Reclaimed water is wastewater that has been cleaned and highly treated to a level that is safe for use in irrigation, industrial coolant, dust control or in water features. While not intended for drinking water, the water is proven safe for plants, and even human contact in irrigated areas like parks, playing fields, construction sites and golf courses. By using this water for irrigation, we can preserve and enhance our precious drinking water supply and our environment.
The City uses reclaimed water primarily as irrigation for golf courses, a cemetery, and Boulder Highway medians. Reclaimed water also supplies the nine ponds that support the Henderson Bird Viewing Preserve. The City annually reuses approximately 30% of our reclaimed water for these purposes.
Reclaimed water that is not used for the above purposes is returned to the Colorado River system and earns return flow credits. That means for every gallon of reclaimed water we return to the system, we are able to take an equal amount of drinking water back out for use by the Henderson community. Reclaimed water is an essential component to ensuring our community's future water resources.