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Highlands Ranch Water Supply

The community’s water supply comes from a combination of surface water from the South Platte River and groundwater from three deep bedrock aquifers beneath Highlands Ranch. Use of these two water sources is known as a conjunctive use system. Surface water is renewable while deep groundwater is mainly non-renewable; therefore, the groundwater is used primarily as a back-up water source to the surface water. The community uses on average 85% surface water annually. Approximately one-half of this water is legally reusable. This means it can be recaptured after its first use and used multiple times until it is used to extinction.


Frequently Asked Questions

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For more information about the community’s water supply including a fact sheet addressing some frequently asked questions, a link to the latest Water Wise Guide, or tips on how to read your meter, click the links below.


Frequently Asked Questions

Does Centennial Water have enough water to supply Highlands Ranch when it is fully built out and beyond?

Yes. Centennial Water has a water portfolio today to meet future demands for all Highlands Ranch customers. With present water sources, we will only use a fraction of our annual allowance of groundwater.

What is Centennial Water doing to ensure Highlands Ranch has adequate water at a reasonable cost in the future?

Centennial Water is taking several steps to enhance its existing water sources and assure their long-term cost-effectiveness. As much as 100 percent of our past water supply has come from South Platte River sources. Our water planning and operations have increased our flexibility to use South Platte River diversions through storage, expanded treatment capacity, reuse and injection into the aquifers.

Ongoing efforts include:

  • Maximizing the reuse of water supplies as allowed by law and decree
  • Utilizing South Platte Reservoir, a 6,400-acre-foot storage reservoir completed in 2007, which stores surface water
  • Seeking and acquiring additional cost-effective surface water supplies
  • Diversification of our water portfolio: A combination of surface and groundwater sources
  • Continuing innovative programs such as aquifer storage and recovery, a process that recharges water back into the aquifers when the surface supply allows
  • Supporting a community-wide water conservation program, including water budgets
  • Participating in state and regional water planning efforts, such as the South Metro Water Supply Authority
  • The reallocation of Chatfield Reservoir water storage for municipal use
  • Regional cooperation and reuse of water through the Water Infrastructure and Supply Efficiency (WISE) project

Do the aquifers have a limited supply of water?

Yes, deep bedrock aquifers have a limited supply of water. However, the laws that regulate groundwater use limit annual pumping to no more than one percent of the total available water. Groundwater is only a portion of our supply portfolio, and Centennial has pumped 9% of the decreed rate allowed in the last 30 years.

In Highlands Ranch, we use surface water sources to the maximum practical extent so that groundwater pumping is reduced. Also, as part of our aquifer storage and recovery program, we periodically replenish the aquifers with high-quality treated surface water.

What is aquifer storage and recovery (ASR)?

Centennial Water recharges treated surface water into the aquifers to reduce the net withdrawal and to sustain pumping capacity at economical levels. Centennial has, to date, injected more than 14,000 acre feet of water into 19 wells, replacing a portion of what has been withdrawn.

The amount of water returned to the aquifers in any specific year is highly dependent upon surface water yields from the South Platte River and other operational factors. Continued investment in our water supply infrastructure has expanded our ASR capacity.

Why doesn’t Centennial Water completely eliminate its use of groundwater?

During droughts, when surface supplies are below average, access to a groundwater source can be invaluable. Consequently, Centennial has opted for a supply plan that balances surface and groundwater sources in a cost-effective way. Groundwater is important to a water supply portfolio because it is of consistently good quality, is not dependent upon seasonal snowpack, and it can be developed with minimal environmental impacts. Groundwater is also not subject to evaporation losses, and is not exposed to surface contamination.

How is Centennial Water planning ahead as a player in the broader water situation in Douglas County?

Centennial Water is a leader in developing surface water sources, operating integrated groundwater and surface systems, and implementing ASR.

Centennial Water is an active participant in the South Metro Water Supply Authority, and the WISE project with Denver and Aurora.

How does water conservation impact our water supply?

As water conservation increases, the amount of water used per customer decreases, thus reducing our reliance on groundwater. A number of conservation measures have already been implemented in Highlands Ranch including:

  • Water budgets for each customer linked to a conservation-based rate structure
  • Metering all water users
  • Code requirement for water-efficient fixtures in all buildings
  • Efficient, computer-controlled irrigation techniques
  • System leak detection and repair program
  • System-wide water audits
  • Water conservation public information programs

For More Information

Centennial Water & Sanitation District

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