Email katie@savebearcreeklakepark.org to join our mailing list for updates and events. Check your spam/junk folder for replies.
The Bear Creek Lake Reallocation Feasibility Study is investigating the potential impacts of increasing water storage in the Bear Creek Reservoir. Alternatives being studied include a tenfold increase in the volume of the Reservoir, which would reduce land acreage of Bear Creek Lake Park by over 500 acres.
The darker blue above shows the reservoir at its typical maximum storage volume of 2,000 acre feet. The lighter blue shows what the surface of the reservoir would be at 22,000 acre feet. As you can see, the majority of the Bear and Turkey Creek riparian zones (nearly two river miles) would be consumed by the expansion. Image source: Martin and Wood Water Consultants.
Background: The Bear Creek Dam and Reservoir Project was completed in 1979 by the U.S. Army Corps of Engineers (Corps) for the purpose of flood control. The City of Lakewood has managed the Bear Creek Lake Park pursuant to a lease with the Corps since 1982. In 2015, The Colorado Water Plan set a goal to increase statewide water storage by 400,000 AF (acre feet). The Colorado Water Conservation Board (CWCB) requested a study to determine whether storage capacity in Bear Creek Lake could be reallocated from Flood Control to Water Supply. The proposal seeks to expand the pool from 2,000 AF to up to 22,000 AF. In 2016, the Water Board solicited potential partners in the project. Cities interested in the largest shares of an expanded pool were Brighton, Berthoud and Dacono.
In September of 2021, the CWCB and the Corps decided to move forward with a three year study to determine feasibility of the project. The Bear Creek Lake Reallocation Feasibility Study is currently in the Public Scoping Phase.
Considerations include the flood risk of an expanded reservoir, economic viability, flow/supply potential into the reservoir, impacts on the BCLP, and environmental impacts. A 20,000 acre feet expansion would reduce the land acreage in the Park by over 500 acres and inundate over a mile of Bear Creek. Cottonwood trees along Bear and Turkey Creek would be removed, destroying significant stretches of riparian habitat.
While the primary purpose of the dam is flood control, a reconnaissance study completed by the Corps in 2015 found that an additional 20,000 AF of storage could be available in Bear Creek Lake without undermining flood protection. A Semi-Quantitative Risk Assessment (SQRA) was completed by the Corps in 2020. It concluded that while flood risk would increase, that risk would remain within tolerable limits. The Assessment cautioned that significant infrastructure improvements may be required, and the Risk Management Center Director ‘expressed concern about the risk of undertaking a reallocation study that may recommend trading flood risk management benefits for water supply benefits.’ The associated Memorandum (Bear Creek Dam Periodic Assessment 01 Update- 12/08/20) is available on the information page of this website.
Expanding the reservoir will not result in “just a bigger lake” for water-based recreation. The water level in the reservoir would fluctuate, and the full volume of 22,000 AF would only be available in higher water years. After stored water is drawn out of the reservoir, hundreds of acres of mud flats could remain until the next high water year. In drought scenarios, these barren regions could persist for years. If you remember the floods of 2013 and 2015, the proposed maximum volume would exceed the peak levels of those flood events, but the impacted acres would not recover.
How much of this precious community and environmental resource must we sacrifice to accommodate growth and development in other regions of the state? Lower-impact alternatives exist which could provide additional water storage while preserving the irreplaceable assets of the Park and its ecosystem. Alternatives under consideration include “no change” and lower levels of expansion in the Reservoir. Another alternative is deepening the current pool to allow for increased storage while impacting fewer acres of the Park. Offsite storage alternatives include repurposing sand and gravel pits to serve as water storage reservoirs. Water Education Colorado estimates that 10,000 acre feet of storage potential is being created every year through gravel mining along the South Platte. Many such reservoirs are already in use, much closer to the municipal partners of Brighton, Berthoud and Dacono. https://www.watereducationcolorado.org/publications-and-radio/headwaters-magazine/spring-2021-storage/south-platte-reclaiming-gravel-pits-as-reservoirs/
The Colorado Water Conservation Board (CWCB) and the U.S. Army Corps of Engineers (USACE) are coordinating on the study. Their website for this project is here: https://cwcb.colorado.gov/bearcreeklake
Lakewood also has a webpage with helpful information here: https://www.lakewood.org/Government/Departments/Community-Resources/Projects/Bear-Creek-Reservoir-expansion-proposal
