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Department:
Parks, Recreation and Cultural Services
Parks, Recreation, and Cultural Services

Key Dates

March 6, 2023

Community Meeting

Survey will be open March 6- 30

March 9, 2023

Presentation to Parks, Recreation and Cultural Services Advisory Board

March 27, 2023

Presentation to City Council during work session
Note: There is no public comment during work sessions.

April 2023

Final summary of the design alternatives will be presented to City Leadership for a decision on which alternative to move forward with for installation.

May 2023

Bid process and selection of a contractor

TBD Construction starts
TBD Project completion
Planning Phase

Current status

Aeration Design 1 Selected for Installation – Motorized Boating to Continue with this Design

With approximately $450,000 from the American Rescue Plan Act (ARPA), the City is working with a consultant to design and install a permanent system to address lake health issues.  The main objective of the system is to implement a continuous aeration system and an as-needed injection system capable of distributing liquid treatment to the lake to combat blue green algae blooms and fish kills.  Design 1 has been selected which consists of one (1) compressor with eight (8) double-disk membrane diffusers.  The aeration lines and diffusers are situated on the lakebed and are placed to target the deepest parts of the lake while maintaining full lake coverage.  Injection lines are coupled with the aeration lines to allow for the dispersal of enzymes into the water body on an as-needed basis.  The design includes a structure, built on the east side of the lake, to house the compressors and injection system tank. 

Design 1 will turn over the water in the lake at a 0.45 rate per day which results in the lake turning over about every two (2) days.  This level of effort will reduce the excess nutrient content within the lake.  Due to its focus on treating the deepest parts of the lake, Design 1 supports continued motorized activity on Prospect Lake.

The City released a Request for Proposal (RFP) for construction of the Prospect Lake Aeration System on March 4, 2024.  After the RFP closes on April 5, 2024, the City will select a contractor and make a formal announcement including the anticipated construction schedule.  The Parks, Recreation and Cultural Services Department will also hold an informational meeting for lake users to provide information on the construction process and any other updates regarding Prospect Lake.

Lake aeration basics

Lake aeration is a process of introducing oxygen into a body of water to improve its water quality. The aerator works by forcing air bubbles through the lake water. The oxygen in the air bubbles then diffuses into the lake, which helps reduce the levels of pollutants in the water and increase the number of beneficial bacteria in the lake among other water quality improvements. Both design alternatives utilize aeration to improve water quality with Design 2 incorporating ultrasonic algae control units that float on the surface of the water to further inhibit algae growth.

About Prospect Lake

Prospect Lake is located in the southeast corner of Memorial Park.  The land where the lake is located was deeded by General William Jackson Palmer in 1890. It served as the reservoir to irrigate Evergreen Cemetery until a non-potable irrigation system was installed in 1950. Since that time, Prospect Lake has served as a recreational amenity for both residents and visitors alike.