Groundwater

A primary source

Groundwater is the water found beneath the Earth’s surface. This water typically comes from rainfall and snowmelt and percolates down through the soil and fractures in the rock formations. It collects and forms aquifers. It takes decades, centuries or longer for the water to seep from the Earth’s surface into these aquifers.

Castle Rock, and most South Metro communities, have relied solely on aquifers for water supply. There are three primary aquifers located in the Denver area and range from 1,000 to 2,000 feet below the surface. They are the Denver, Arapahoe and Laramie aquifers. These aquifers are slowly being depleted and transitioning to renewable sources which are replenished each year has been a priority for Castle Rock Water.

Investments and improvements

Maximizing the benefits of past investments in the Town’s Denver Basin groundwater supply remains an important piece of the long-term water plan puzzle. Maintaining and developing this supply to meet the demands of continuing growth, in the short term, and to provide reliability, but a smaller supply role in the long-term, is all part of the plan.

This existing aquifer system is being modified to provide expanded capabilities like storing water supplies. Also known as aquifer storage and recovery, this provides a key component of our long-term water storage plan. Treated, excess water supplies will be pumped back down into the aquifer for storage. Water stored deep underground doesn’t evaporate like supplies stored in conventional surface reservoirs.

Ultimately, additional improvements and continued maintenance of the Town’s groundwater system will provide an added layer of long-term reliability. So, as groundwater becomes a smaller and smaller component of the day-to-day water supply, it will continue to safeguard us against future droughts.