Mount Vernon approves up to $6,540 for quarry vegetation treatment after DNR and extension guidance

The Mount Vernon City Council approved an aquatic control proposal (not to exceed $6,540) to manage surface vegetation in the town quarry pond after staff said Iowa Department of Natural Resources and Iowa State Extension identified limited management options.

City staff described test results and seasonal behavior: aquatic vegetation can rapidly reappear in warm weather and the quarry's spring-fed but low-flow conditions create habitat that favors invasive growth. Staff said the initial treatment is a management step, not a one-time cure, and likely will require periodic follow-up treatments in future years.

Council members asked about using dye to shade the pond and reduce sunlight penetration; staff said some practitioners reported aesthetic concerns from residents but that dye can also reduce UV and slow vegetation growth. An aquatic-control vendor told staff that dye had been used elsewhere and could be effective in shading the water, though the transcript records no guarantee of performance.

Why this matters: the council emphasized recreational and programmatic uses of the pond — staff noted prior investments (kayaks and youth programs) that cannot be used while vegetation blocks paddling and swimming. Approving the treatment aims to restore recreational value and park programming while balancing ecological and aesthetic considerations.

The action approved was a not-to-exceed contract with an aquatic-control vendor; the figure in the record is $6,540. Staff said the proposal allows staging (start without dye and evaluate results) and cautioned residents that ongoing annual management is probable if conditions persist.

Council approved the measure by voice vote and directed staff to implement the treatment under the not-to-exceed limit.