Some of the milestones in Highlands Ranch Water’s 45-year history happened quietly, hundreds or even one thousand feet below ground. One of those milestones is Aquifer Storage and Recovery (ASR), a strategy that strengthens long-term water security for Highlands Ranch.

Early on, leaders worked to build a diversified water supply. Investments in water rights and reservoir storage allowed the district to develop what’s known as a conjunctive use system, combining surface water and groundwater to maximize reliability.

Surface water comes primarily from Plum Creek and the South Platte River, while groundwater is withdrawn from the Denver, Arapahoe and Laramie-Fox Hills aquifers. Historically, most of Highlands Ranch’s water supply has come from renewable surface sources, with groundwater providing an important backup during dry periods.

Because groundwater in these aquifers is limited, in the early 1990’s Highlands Ranch Water began exploring ways to replenish and extend the life of the resource. Aquifer Storage and Recovery does exactly that. Fully treated surface water is injected into underground aquifers so it can be stored and used later when supplies are tighter. Unlike surface reservoirs, water stored underground is protected from evaporation and uses natural storage space already available below ground.

In 1992, the district demonstrated that ASR could work in its wells, making it one of the first water districts in Colorado to successfully use the technology. ASR allows treated surface water to be injected into underground aquifers where it can be stored until it’s needed.

Today, 25 of the district’s 38 active wells are equipped to perform ASR, and more than 14,000 acre-feet of water has been stored into local aquifers over time.

As Highlands Ranch Water celebrates 45 years of service, ASR remains one of the many tools helping ensure a reliable water future for our community.