Maitland City Talk

Hydrilla under control in Maitland

  • By
  • | 9:30 a.m. July 20, 2011
Hydrilla control in Maitland
Hydrilla control in Maitland
  • Winter Park - Maitland Observer
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The city of Maitland has an extensive aquatic vegetation management program targeted at controlling exotic species that have inhabited our waterways for decades. Introduced unknowingly into Florida, these species originated in continents such as Asia and Africa where native predators were able to maintain their populations at sustainable levels through the same means that native species are naturally controlled in our state.

Over the years, Maitland has experienced fluctuating intrusions of hydrilla (Hydrilla verticillata), the most noxious and maintenance-intensive aquatic species that the city has accepted the responsibility of controlling. Well-suited to Florida’s wet, consistently hot and nutrient-rich habitat, this “super plant” has thrived with the absence of natural means of control. Measured in a laboratory to branch and grow over 90 inches a day, hydrilla maintenance is accomplished through a variety of means: chemical, biological and mechanical control. Currently, the city utilizes an integrative management approach focused on a number of hydrilla-specific herbicides coupled with the stocking of triploid grass carp.

There are presently six bodies of water within the city of Maitland that require frequent control measures to reduce hydrilla densities: Lakes Maitland, Nina, Minnehaha, Park, Gem and Shadow. All of these lakes have been stocked with low levels of triploid grass carp (from 1.5 to 3 per surface acre) to consume anticipated hydrilla regrowth after chemical treatments have been conducted. This fish’s favorite food is hydrilla, and it has been genetically engineered to be incapable of reproduction, so the city is able to stock a specific number of fish with the knowledge that the population cannot increase beyond desired levels.

Though originally very straightforward and effective, chemical control of hydrilla has become very complicated due to herbicide resistance issues within a number of Florida’s lakes. In recent years, Lake Minnehaha experienced a failed treatment due to product resistance, which resulted in almost 75 percent of the water body being “topped out” with vegetation and rendered temporarily un-navigable. Since this event, the Maitland, in cooperation with Winter Park and the Florida Fish and Wildlife Conservations Commission, has begun rotating chemical usage on the Chain of Lakes to ensure that the lowest levels of hydrilla presence possible are maintained without promoting further chemical resistance.

Though hydrilla can never be completely eradicated (even when no plants are visible, the species still maintains tubers beneath the lake’s sediment that can lay dormant for decades and later regrow), Maitland, Winter Park and FWC have managed to bring existing populations to the lowest levels that we have seen within our jurisdiction in years. A recent survey conducted on the Chain of Lakes showed only scattered presence with densities limited to shoreline coverage along the north shore of Lake Maitland.

—Marissa Williams

Maitland Storm water/lakes manager

City Council Agenda

City Council meets the second and fourth Monday of the month at 6:30 p.m. The next meeting is scheduled for July 25 in the Council Chambers, 1776 Independence Lane. Below are items that will be addressed at that meeting.

Consent Agenda:

Approve Council Minutes of July 11

Approve Budget Workshop Minutes of July 11 and July 18


• Annual Budget – Set Proposed Millage Rate (TRIM), Date, Time and Place for Public Hearing

• Appointments:

• Parks and Recreation Advisory Board (2)

• Planning and Zoning Commission (2)

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