The Downstream Reservoir Water Storage Program, which has been under development since 1997, allows Denver Water to store and release water using reclaimed gravel mines north of downtown Denver.
Approximately half of Denver Water’s water supply is from the Colorado River. Because that water is not native to the South Platte River, it may be used and reused multiple times, including storing it in the downstream reservoirs.
When water is needed by a more senior water right holder located downstream of these facilities, Denver Water can release the water stored in the downstream reservoirs and store a like amount in our mountain storage or divert it directly at our water treatment plant intakes. This operation is known as an exchange and helps meet customer demand, maintain water storage in our mountains reservoirs, and makes the most of the water we have.
Denver Water has been reusing water by exchange since the early 1970s. However, the Downstream Reservoir Water Storage Program increases the opportunity for Denver Water to put its reusable water supplies to use by first storing the water in the reservoirs and then releasing it when additional exchanges can be made.
At completion of construction, there will be nine reservoirs divided into three complexes, which will have an estimated total storage volume of approximately 30,000 acre-feet of water. The reservoirs are along the South Platte River, north of Denver, and extend from Commerce City to Fort Lupton.
South Reservoir Complex
Bambei-Walker and Welby reservoirs, near Commerce City, form the South Reservoir Complex and began operation in spring 2009.
North Reservoir Complex
Denver Water continues to develop its North Reservoir Complex, which is south of 120th Avenue and east of the South Platte River. There are five reservoirs in this complex, including Howe-Haller A, Howe-Haller B, Hazeltine, Dunes and Tanabe. Denver Water began storing water in Dunes and Tanabe by gravity in spring 2018 and in Howe-Haller B Reservoir beginning in fall 2024.
Mining has been completed in Howe-Haller A and Hazeltine reservoirs. Additional infrastructure required to begin operating these reservoirs by gravity is expected to be completed by the end of 2026.
Lupton Lakes Complex
Denver Water also continues to move forward on its third complex. The Lupton Lakes Complex, in Fort Lupton, is expected to be operational sometime after 2030. Lupton Lakes consists of two reservoirs, the north and south cells.
Mining at the north cell has been completed and the liner has been installed; mining on the south cell continues, but the reservoir liner was completed using a groundwater cutoff wall. Construction of the inlet/outlet pipeline and river diversion structure was completed in 2022.
Water level fluctuations
Typically, all the reservoirs in the Downstream Reservoir Water Storage Program will be filled and drained on an annual basis. In general, these reservoirs will fill in the winter and drain in the summer, when downstream users — typically farmers — need water for irrigation.
Maps of the Project
Downstream Lupton Lakes Complex
