Strontia Springs Reservoir Sediment Management Project

Sedimentation of the Strontia Springs Reservoir has increased over time and became a major concern after the Buffalo Creek Fire in May of 1996, and subsequent rainstorm events in July 1996.

Furthermore, the 2002 Hayman Fire has further exacerbated the adverse effects of sediment accumulation within the reservoir. The immediate catchment basin above Strontia Springs Reservoir has experienced over 78,000 acres of area being burned, or about 15% of the drainage area of the reservoir catchment. The burn areas have significantly increased the sediment loading and accumulation in the reservoir.

The Strontia Springs Dam and Reservoir is an on-stream water storage facility located on the South Platte River in Jefferson and Douglas Counties, Colorado, in the Pike National Forest. The dam and reservoir, owned and operated by Denver Water, was completed in 1982 and upon completion had the capacity to store up to 7,700 acre-feet of water. To maintain continued operation of the facility and reduce future maintenance cost, Denver Water decided to develop a plan to remove sediment from the reservoir. Although major operational impacts may not occur until 2075 (Denver Water, 2016), Denver Water’s interest is to manage the reservoir in the near term as a sustainable resource and create a sediment management plan.

PIC led the effort to perform a study for Phase 1 of the Sediment Management Concept at the Strontia Springs Reservoir. The PIC led a team included several leading dam and tunnel experts. The team performed feasibility evaluations to remove sediment from the reservoir using the original dam’s water bypass tunnel. Services included sediment transport analysis, tunnel modifications evaluations, and environmental permitting research. The sediment transport analysis involved modeling to evaluate sediment flushing potential with alternative reservoir management operations; water level drawdown and sediment flushing flows.