After several years of near-record low snowpack and drought, 2019 is shaping up to be a very good water year across the state.
Water managers can breathe a collective sigh of relief. But in reality, one good year does not mean we are out of the woods with our water supply.
Colorado is experiencing aridification, the process of increasing long term drought. About 80% of the state’s population lives on the Front Range, which averages less than 15 inches of precipitation annually.
This requires all water providers to think outside the box. It means we have to save water, reuse it when possible and be creative in how we acquire and store water.
Aurora Water provides water to over 374,000 residents. We rely on a complex system of storage, conservation and reuse of renewable water supplies. Aurora’s 12 storage reservoirs are the backbone of our water system, holding 156,000 acre-feet — enough water to supply the city for up to three years.
Recent patterns make storage even more critical across the state. Deeper droughts, more extreme rain events and a downward trend in annual snowpack over the past 40 years are affecting all of Colorado. We look to storage in both years of abundance and drought as a buffer to high variability, allowing us to meet our customer’s needs.
As the third-largest city in the state, we leverage the water we own the rights to. Since 95% of our water rights are fully reusable under Colorado’s complex water laws, Aurora Water stretches our supplies through reuse.
And we have been doing it a very long time. We started using reclaimed water in 1968 for municipal golf courses. Today, Aurora has the highest reuse rate in the state due to our Prairie Waters System, which provides the city up to 10 million gallons per day — returning high-quality drinking water to the homes from which it came.
The largest potable reuse facility in Colorado, Prairie Waters, recaptures return flows from the South Platte River, using an effective multibarrier treatment process to ensure the water is indistinguishable from our traditional supply.
Aurora is also examining more creative ways to store water, including Aquifer Storage and Recovery (ASR), which helps recharge ground water.
Commonly used in the Southwest, including Arizona, ASR will allow us to store water underground and withdraw it when needed. This protects the water from evaporation and water quality issues from algae, and is much less expensive to build than a traditional surface water reservoir.
But that doesn’t mean that reservoirs are obsolete. Deep, high-altitude reservoirs benefit from lower evaporative rates and greater capacity, so Aurora Water is planning additional off-stream reservoirs to increase the operational efficiency to our system.
Even when we do need to acquire additional water, we have to look where many won’t. Last year, Aurora purchased 1,411 acre feet of water rights from a gold mine near Alma. The London Mine is pumping from a contained basin below the mine to keep water out of the mine, reducing or eliminating a source of contamination to a local stream.
This water is high quality and fully reusable, which is a true win for Aurora and a benefit for the environment, all without impacting agricultural water in the South Platte basin.
Maintaining a sustainable water resource requires that Aurora Water plans well into the future. This begins with Aurora’s comprehensive plan, so we understand how growth will impact our system over time.
By refining these needs though master plans, we can be more efficient with our projects. Aurora’s development code incorporates conservation measures, including limits on turf, incentives for native grasses and a tap fee structure based on projected water use rather than flat fees.
A good water year does not mean we get a year off conserving water. Our dynamic conservation program provides rebates and low-income assistance programs for water-wise landscaping and indoor fixture replacement.
We communicate with large irrigators to educate them on their irrigation needs based on weather conditions. We also rebate for rain sensors and smart irrigation controllers, dramatically reducing water waste.
In 2017, these conservation measures saved over 160 million gallons of water, 1% of Aurora’s annual demands.
As a result, Aurora Water is treating less water today than we did in 2000, even with a population increase of almost 100,000. We ensure future generations of customers understand the importance of water stewardship.
Our education team is actively involved in curriculum development and programing in both Aurora Public Schools and Cherry Creek School District and reached over 1,600 students last year.
While we are grateful for abundant snow fall this year that will help refill depleted streams and reservoirs, we need to manage our precious water in Colorado with a long-term, not short-term, lens.
Marshall Brown is general manager for Aurora Water.