Plant Control | Spring Lake

Nuisance aquatic plant control with the select use of herbicides is a primary focus of the Spring Lake improvement program. Beginning in May and continuing throughout the summer, biologists conduct GPS-guided surveys of Spring Lake to identify areas requiring treatment. The treatments are conducted under a permit issued by the Michigan Department of Environment, Great Lakes, and Energy. The permit lists herbicides approved for use, dose rates, and areas of the lake where treatments are allowed.

At the time of treatment, signs are posted along the shoreline of treated areas that list use restrictions that apply, if any. Generally, there are no fishing restrictions, a 24-hour swimming restriction, and in some situations a limited irrigation restriction. The irrigation restrictions do not apply to established lawns. The restrictions only apply to portions of the lake receiving treatment, not the entire lake.

The plant control program on Spring Lake is limited and designed to control invasive plants while preserving beneficial plants that are essential to a well-balanced fishery and a healthy lake. Maintaining a diversity of beneficial plants is as important as controlling nuisance and exotic species.

The distribution and abundance of aquatic plants are dependent on several variables including light penetration, bottom type, temperature, water levels, and the availability of plant nutrients. The term aquatic plants" includes both the algae and the larger aquatic plants or macrophytes. The macrophytes can be categorized into four groups: emergent, floating-leaved, submersed, and free floating. Each plant group provides unique habitat essential for a healthy fishery.

Eurasian milfoil

Starry stonewort

Plant Control Frequently Asked Questions

Who oversees the plant control program?

Plant control activities are coordinated under the direction of the boards's environmental consultant, Progressive Companies. Beginning in May and continuing through August, scientists from Progressive Companies conduct GPS-guided surveys of the lake to identify problem areas, and detailed treatment maps are provided to the plant control contractor. Progressive then conducts follow-up surveys throughout the growing season to evaluate treatment effectiveness and the need for additional treatments.

Who conducts the herbicide treatments?

Herbicide treatments in Spring Lake are conducted by PLM Lake and Land Management.

What plants are targeted for control?

The Spring Lake plant control program focuses primarily on invasive, exotic species. An exotic species is one that is found outside of its natural range. Outside their natural range, exotic plants have no natural competitors or predators to help keep them in check. They can quickly outcompete native plants and gain dominance in the lake. Eurasian milfoil is the primary exotic species targeted for control in Spring Lake.

Why are there still plants in the lake following treatments?

Not all plants are treated. The goal of the program is to strike a balance by controlling invasive plant species and maintaining beneficial species. We do not want to remove all the plants in the lake. This would be bad for the fishery and cause a host of other problems, such as algae blooms.

Is a permit required?

In Michigan, a permit must be acquired from the Department of Environment, Great Lakes, and Energy (EGLE, formerly the DEQ), before herbicides are applied to inland lakes. The permit lists the herbicides that are approved for use, dose rates, use restrictions, and indicates specific areas of the lake where treatments are allowed. Permit requirements are designed to protect public health and the environment.

Are herbicide treatments safe?

The aquatic herbicides that are permitted by the Department of Environment, Great Lakes, and Energy (EGLE) are registered by the United States Environmental Protection Agency and the Michigan Department of Agriculture and Rural Development. They also undergo toxicological review by EGLE. In Michigan, aquatic herbicide use requires a EGLE permit. The permit lists herbicides approved for use in the lake, respective dose rates, and shows specific areas in the lake where treatments are allowed. If herbicides are applied according to label instructions and permit requirements, they should pose no danger to public health and the environment.

How do herbicide treatments impact swimming and fishing?

All herbicides, except algaecides, have a 24-hour swimming restriction, but only in the area where treatment has occurred as indicated by state-required posting signs. If there are no posting signs, or the sign indicates that only algaecides were applied, there are no swimming restrictions. There are no fishing restrictions for any herbicide treatments.

When can I water my lawn following a treatment?

If you draw water from the lake for irrigation, be sure to read the sign posted along your shoreline at the time of treatment. Most irrigation restrictions do not apply to established lawns. However, it you water flowers or a garden, you should adhere to the irrigation restrictions posted on the sign.

Why didn’t my property get a treatment notice sign?

If there is no sign posted along your property, it means your area was not treated and there are no use restrictions. State regulations require that areas within 100 feet of treatment areas be posted with a sign that lists herbicides applied and the associated use restrictions. Not every property gets treated every time; which properties get treatment depends on where the plants are found during lake surveys.

Is there a permanent fix to the problem?

If conditions are favorable, aquatic plants will grow. However, there are steps property owners can take to help minimize plant growth in the lake such as limiting the use of lawn fertilizers and maintaining natural vegetation along the shoreline to prevent nutrients from washing into the lake.

What can I do to prevent the spread of aquatic invasive species in Spring Lake?

To help prevent the spread of invasive species, a new state law requires drain plugs to be pulled, water to be drained, and plants and debris to be removed from boats and trailers before trailering. If you trailer your boat to other lakes, be sure to thoroughly wash your boat, motor, and trailer before launching back into Spring Lake. With invasive species, an ounce of prevention is worth a pound of cure!