Reservoir storage is a key component to operating the GMS and WAS augmentation plans. Storing water during times of free river conditions, or when CCWCD’s reservoirs and water rights are in priority, is critical for augmenting during the driest parts of the year and long term droughts. Numerous reservoirs have been constructed in the South Platte River basin to store as much water as possible. To date, CCWCD has approximately 20,000-acre feet of water storage capacity. The Siebring Reservoir slurry wall and pump station was the first project in Colorado where a soil-bentonite wall was used to line a gravel pit. This unique lining allows for below grade storage with minimal groundwater interaction.

Recharge ponds are shallow depressions excavated from the land in strategic and geologically significant areas. The pond allows water diverted into the pond to infiltrate into the underlying aquifer and slowly migrate back to the river. Recharge projects allow more delay in returns, allowing us to take advantage of the time it takes the water to returns to the river. CCWCD has several large recharge projects. The Box Elder Recharge project was decreed by Central in 1982 with a maximum yearly diversion of 3,000- acre feet. The Kiowa and Milliron Recharge facilities were constructed in 1981 and 1982, respectively. The Orchard Recharge Project is unique because the water diversions are provided by groundwater wells rather than a surface diversion. Land was purchased near the river east of Orchard for the Walker Recharge project in late 2016 and saw it’s first water deliveries in 2023. Smaller ponds have been built along the irrigation canals in partnership with landowners, where expenses and water credits are negotiated in contracts annually. CCWCD has also constructed innovative “hybrid” projects, such as Nissen Reservoir. This project consists of infiltration ponds which recharge an area within an un-mined gravel pit with a slurry wall liner, serving the best of both worlds.

CCWCD’s Board of Directors began purchasing senior water rights shortly after the formation of GMS in 1973. This water is used to fill reservoirs, recharge ponds and direct supply to the South Platte River. Some of the earliest stock certificates date back to 1980. The District and two Subdistricts have assembled a water portfolio that contains rights in thirty-four different ditch and reservoir companies. CCWCD has had many leases over the years with municipalities such as: Aurora, Thornton, Longmont, and Greeley. These types of water leases are slowly dwindling as more and more municipalities are not renewing longterm leases. CCWCD Board of Directors are working hard to replace these leases with reservoirs, recharge ponds and surface water rights.