Sloan’s Lake is a shallow urban lake that has accumulated a significant amount of sediment over the past several decades, resulting in an average water depth of 3.5 feet deep across the lake. In 2020, Denver Parks and Recreation (DPR) partnered with the Denver Department of Public Health and Environment (DDPHE), Denver Department of Transportation and Infrastructure (DOTI) Wastewater Management, and the Mile High Flood District (MHFD) to evaluate the existing conditions of the lake that contribute to an increased occurrence of algae blooms, fish kills, and other aquatic habitat health concerns.
DPR has contracted an environmental consulting firm to perform an assessment of Sloan’s Lake. This analysis includes bathymetric mapping (a topography map of the lake floor), water quality sensor installation and analyses, and sediment sampling. Water quality sensors were installed summer 2021 to collect real-time data of the water conditions within the lake. Analysis of this data will assist in understanding the existing conditions along with changes over time to guide decision making on how to best manage the lake.
DPR is also coordinating with the MHFD to analyze the quality of water entering the lake. This study includes the watershed outside of the City and County of Denver in Lakewood, Wheat Ridge, Jefferson County, and Edgewater.
DPR will gather additional data on the sediment to determine the feasibility and rough costs for possible lake dredging. The in-lake water quality sensors will be redeployed on the lake surface to collect data throughout the 2022 summer season.
The DPR lake management operations team will also perform a phosphorus mitigation treatment during spring 2022. The intent of the treatment is to reduce the amount of phosphorus available to algae, hopefully slowing down its growth and preventing future algae blooms. The treatment will not impact recreational use of the lake. Depending on the results of the first treatment, an additional treatment may occur over the summer.
DDPHE will also assist with collection of water and sediment samples related to both the phosphorus mitigation treatment and ongoing long-term monitoring. DDPHE will contribute to subsequent analyses, continued assessment and other management actions as needed to support the improvement of the lake’s water quality.