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Highlands Ranch Water Supply

The foundation of our community’s water supply is based on surface water and ground water, commonly referred to as a conjunctive use system. This means that water sources include both surface water from the South Platte River and groundwater from wells throughout Highlands Ranch. Over the past 20 years, more than 80% of our water supply has come from surface water. To firm up our surface water system, especially in times of drought, a network of groundwater wells makes a smaller, but important contribution to system reliability. 

Centennial Water’s diverse water portfolio is unique among Douglas County water providers. In 2011, 99% of our community’s water supply came from surface water.


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, and injection into the aquifer.

Ongoing efforts include:

  • 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, where water is recharged back into the aquifers when surface supply allows.
  • Supporting a community-wide water conservation program.
  • Participating in state and regional water planning efforts, such as the South Metro Water Supply Authority and the Douglas County Water Resource Authority

Do the aquifers have a finite supply of water?

Yes, deep bedrock aquifers have a finite supply. However, the laws that regulate our 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 a net of nine percent of the decreed rate allowed
in the last 30 years.

In Highlands Ranch, we utilize surface water sources to the maximum practical extent so that aquifer 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 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 4.5 billion gallons 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 can be developed with minimal environmental impacts. Groundwater is also not subject to evaporation losses, and is not exposed to surface contamination.

Centennial has established a goal that water supply in Highlands Ranch will utilize an average of more than 90 percent surface water each year. This target was set after reviewing the long-range cost effectiveness of a more flexible mixture of water sources.

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 Douglas County Water Resources Authority and the regional South Metro Water Supply Authority, and the Water Infrastructure and Supply Efficiency (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:

  • Metering all water users
  • Code requirement for water-efficient fixtures in all buildings
  • Efficient, computer-controlled irrigation techniques
  • System leak detection and repair program
  • Conservation-promoting rate structure that provides a water budget to all customers
  • System-wide water audits
  • Water conservation public information programs

For More Information

Centennial Water & Sanitation District

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