Aurora’s Prairie Waters Project
AWRA Colorado Summer Fieldtrip – June 29, 2010
Article by Steve Smith
The AWRA Colorado Section held its annual summer fieldtrip this year on June 29th, where a group of about 30 members toured the Aurora Prairie Waters Project. The summer fieldtrips have provided opportunities to network with water resources professionals, and are a great excuse to get out and see some of Colorado’s water supply projects and issues firsthand. Previous fieldtrips over the past few years have included touring Denver Water’s Cheesman Dam, observing the Pine Beetle’s effects on the West Slope, and hearing about Denver Water’s Blue River water supply while cruising Lake Dillon in pontoon boats.
Aurora’s Prairie Waters Project is a key element in the City’s plan to provide high quality, reliable water to its customers. The City’s current water supply is a combination of water from the Colorado, Arkansas, and South Platte rivers, with some supply coming from ground water. After its first use, approximately half of the City’s current demand of 50,000 acre-feet per year returns to the South Platte River and can be used to extinction. Prairie Waters provides a means for the city to divert and treat this water. The additional supply from Prairie Waters will provide a sustainable solution to address needs during drought conditions. Prairie Waters is:
• Cost-effective – capital cost of about $650 million (approximately $99 million under budget)
• Environmentally friendly – relies on reuse of existing water supplies, and uses natural filtration processes in combination with state-of-the-art purification at the new Peter D. Binney Water Purification Facility near Aurora Reservoir
• Efficient solution to Aurora’s water needs – construction on the project started in June 2007, and the system will provide up to 10,000 acre-feet per year in 2011 (approximately 20 percent of existing demands)
A unique combination of infrastructure provides a means for the City to recapture the river water in a sustainable way. Water is diverted from the South Platte River using 17 riverbank filtration ground water wells located near the City of Brighton about 300 feet from the South Platte River at a depth of approximately 25 to 30 feet. Water travels from the river through the natural sand and gravel for approximately 10 days before reaching the riverbank filtration wells. Water is then pumped to an aquifer recharge and recovery (ARR) area, where it takes an additional 30 days to pass through natural sands and gravels for an additional level of natural treatment. Once the water is recovered from the ARR area, it is pumped about 34 miles through a 50 mgd capacity pipeline for state-of-the-art treatment at facility near Aurora Reservoir. The water treatment facility uses a combination of softening, advanced ultraviolet treatment, biologically activated filtration, and blending with its existing mountain water supplies to provide water of the highest quality.
Pump Stations and a 34-Mile Pipeline Provide a 50 mgd Project Capacity
The future of the Prairie Waters Project includes potential expansion from its current capacity of approximately 50 mgd to 100 mgd. This expansion is contemplated in approximately thirty years, and would require a new pipeline to be installed adjacent to the existing pipeline using the existing right-of-way. Aurora, Denver Water and South Metro Water Supply Authority are also considering ways to cooperatively work together to efficiently use Prairie Waters system capacity along with water from both Aurora Water and Denver Water to meet a portion of South Metro’s water demands.
The AWRA Colorado board of directors appreciates Aurora Water’s time and support in hosting a very successful fieldtrip. For more information on the Prairie Waters project, visit www.PrairieWaters.org.