Aurora is considering a project to dredge Mastodon Lake and restore the shoreline to improve its water quality and usability.
The lake, which is located at Phillips Park, is currently prone to becoming overrun with aquatic vegetation, among other issues, because it has become shallow over the years, according to city staff. The Aurora City Council is set to consider on Tuesday two contracts totaling nearly $5.2 million to address these issues.
Both contracts — one for dredging at a cost of $4.6 million and another for shoreline restoration at a cost of nearly $580,000 — are proposed to go to Semper Fi Landscaping of Yorkville.
“This is kind of the culmination of a lot of the planning, grant chasing and iterative design work that we’ve been working on for the better part of five, six years now,” Ian Wade of the city’s engineering division said at a meeting of the Aurora City Council’s Infrastructure and Technology Committee on May 11.
He called the project a “long time coming and badly needed.”
Mastodon Lake was first excavated in the 1930s. Since then, sediment and decaying organic matter have built up at the bottom of the lake, dropping the average water depth to less than 2.5 feet, according to a city staff report about the project.
The lake being so shallow opens it up to warming, excessive nutrients and growths of algae and other aquatic vegetation, which limits recreational activities like boating and fishing, staff said in the report.
The city has recently used herbicide to control aquatic vegetation and has vacuumed sediment near the intake for the Phillips Park Golf Course’s irrigation system, the report said, but staff noted that these are not long-term solutions.
So, Aurora started working with engineering firm HR Green to develop a project to address lake conditions, according to the report.
The bottom of the lake is proposed to see hydric dredging and to be reshaped, staff wrote in the report. The project also would create stabilized stone access points for visitors, install fountains and underwater propellers to circulate the water, and do various plantings in the wetlands and uplands to help filter incoming stormwater and help stabilize the shoreline.
The two bids came in just over the project’s $5 million budget, Wade said during the committee meeting earlier this month. However, the bids include things like contingency funds, he said, so the project will likely still be completed within budget.
A large chunk of the project, $4 million, will be paid for using a state grant Aurora accepted last year.
Although a firm timeline has not been established, the work should be wrapped up sometime around the middle of next year, or at the end of next year at the very latest, if the project is approved by the Aurora City Council, according to Wade.
The two contracts are likely to pass on Tuesday, as they were placed on the City Council meeting’s consent agenda, which is used for routine or non-controversial items that are all approved with a single vote.
rsmith@chicagotribune.com
