Dredging inland lakes

© Karsten Eggert | Dreamstime.com

By Mike Scott

Dredging an inland lake is necessary for recreational reasons but can also be destructive to a lake’s local ecosystem.

Dredging requires a permit from the state of Michigan from lake bottomlands owners that outlines pertinent reasons for the request. The process can take anywhere from a few months to a year.

The dredging process though is damaging to the local environment as it can cause the relocation, or permanent damage of many living organisms in the immediate area, such as native plants and insects. Dredging can displace a local fish population which will find plentiful food sources in other areas of the lake. That is why Michigan law mandates dredging projects limit adverse environmental impact.

Dredging and shoreline projects are regulated under Michigan’s Natural Resources and Environmental Protection Act (NREPA), also known as Act 451 of 1994. Within that act are four parts that relate to dredging: Parts 301, 303, 325 and 31.

Part 301 is the main part of the NREPA that impacts dredging and other activities around inland lakes and streams. This section is the main permit authority for dredging if the project is on inland lakes, channels connected to those lakes, rivers or streams, and some ponds. Part 301 regulates not just dredging but excavation, docks and marinas, channel construction and more. It outlines the fact that any dredging below the ordinary water mark generally requires a permit.

Part 303 is designed to provide wetlands protection and would include governance over dredging projects. Wetlands are considered environmentally sensitive because they offer many environmental benefits such as reduced flooding, water quality protection, stabilized shorelines and more. Wetlands generally include marshes, swamps, and bogs so the volume of dredging projects is less given that many wetlands either don’t allow boating, and/or would be less likely to be approved for a dredging permit.

Part 325 governs dredging and construction in the Great Lakes, Lake St. Clair and related waterways. Part 31 is Michigan’s broad water pollution control law that focuses on water quality, pollution prevention, sediment discharge, contamination and more.

All dredging permits are reviewed by the Michigan Department of Environmental (EGLE). Dredging requests must come to EGLE from the lake bottom landowner, or the riparian owner, said Eric Calabro, an inland lakes policy analyst for EGLE’s Wetlands, Lakes, and Streams Program. Individual property owners often apply for a permit themselves to dredge part of the lake bottom that they own. Property owners hire a dredging contractor for the work. That contractor can also for the permit on their clients’ behalf and walk riparian owners through the process.

Approval from all riparian owners whose land is impacted by a dredging request is required.

“You can select an authorized agent on your behalf to make the request if you are a (riparian) owner,” Calabro said. “It’s very common to have those requests come from a contractor.”

Occasionally, property owners may be unclear who owns exact areas of the lake bottom, especially of the property is not platted, he added. EGLE can work with applicants to determine if other owners need to be involved in the application process.

The dredging application serves as a public notice to all interested stakeholders. EGLE may hold a public hearing to address very large or unique dredging permit requests, but those examples are rare. A public hearing is more common when a commercial entity such as a marina applies for dredging, Calabro said.

Most dredging and non-dredging permits submitted to EGLE under NREPA are accepted, Calabro said. The number of those applications that involve a dredging request can range from 750 to more than 1,000, or up to 25 percent of all NREPA-related permit applications. Historically few dredging permits are denied, largely because of collaborative and educational efforts by state agencies.

Riparian owners of dredged inland lake bottomlands must provide a valid reason for the request. Applicants should clearly define why they are hoping to gain a dredging permit because of the potential short-term harm to the local ecosystem, Calabro said. EGLE favors applications that outline least impact on an inland lake and will make suggestions or pose further questions to applicants for this purpose in many instances.

Calabro created an EGLE-themed presentation about state regulations and best practices for construction-based projects on Michigan’s inland lakes. That presentation includes language that specifically guides EGLE’s permit decision process as it pertains to local environmental effects and riparian rights. Specifically:

“The department shall issue a permit if it finds that the structure or project will not adversely affect the public trust or riparian rights. In passing upon an application, the department shall consider the possible effects of the proposed action upon the inland lake or stream and upon waters from which or into which its waters flow and the uses of all such waters, including uses for recreation, fish and wildlife, aesthetics, local government, agriculture, commerce, and industry.”

Common reasons for a dredging request include the removal or control over aquatic plants, increasing water depth to support boats, and to make room for new or extended boat docks. Increasing water depth can include the action of creating channels for boats to travel safely from the shore to deeper parts of the lake. There are environmentally beneficial reasons to dredge as well, such as removing pollutants caused by dumping, leakage into the lake and more.

Calabro said that dredging is most palatable when the action provides a solution to a core problem. “We always look at what is the current impediment to access the waterbody,” Calabro said.

Residents and property owners can submit a request for dredging and create a free account through the state’s MyEnviro Portal, available on the Michigan.gov website or through an online search. Once there, they can find the link to “Sign in for permitting and compliance actions”. Residents can also renew existing registrations, view and print issued permits, and submit reports or management plans with a free portal account.

The portal is a comprehensive website that offers electronic notification, permitting, emissions reporting and compliance application for several environmentally related requests including dredging.

“That is our statue for wetlands and inland lakes that we have to follow,” Calabro said. “We have to avoid as much impact as possible. Dredging is one of the most impactful activities on a lake for all living entities.”

The impact of dredging on a lake’s ecosystem is extreme, said Jo Latimore, Ph.D., an aquatic ecologist and outreach specialist in Michigan State University’s Department of Fisheries and Wildlife and director of the MSU Extension Center for Lakes and Streams. She called dredging a “major disturbance” on plants, algae and invertebrates that live in a lake bottom. The act of dredging can involve heavy equipment that removes or suctions material that houses life.

“You essentially leave behind a desert-like situation for a period of time in that part of the lake,” Latimore said. “It takes a while to recover.”

Dredging requests tend to revolve around lake bottoms located near a shoreline, especially for requests that involve expanded boating channels, swimming areas and dock work. Areas near the shoreline also happens to be where most living entities spend their time on an inland lake.

Guy Savin bought an existing lake services construction and contracting company about 25 years ago, renaming it Savin Lake Services. Savin provides an array of lake services from his headquarters in Clare, Michan, including aquatic weed and algae maintenance, herbicide control, lake dredging and more.

Savin integrated dredging into his business about 15 years ago and focuses on hydraulic dredging, a process that involves pumping mud and muck at the bottom of a lake with water and sediment to a holding cell or retention station as far away as two miles from the pumping site. When the dredging work is completed, his company returns clean water back to the lake to replace any water that was used during the pumping in an effort to minimize the adverse ecological impact.

The process of hydraulic dredging offers several ecological benefits compared to mechanical dredging. Hydraulic dredging causes less property damage in the lake or near the shoreline and is less invasive than mechanical dredging, Savin said. Hydraulic dredging also largely avoids creating a plume of muck and sediments that harm hyperlocal organisms and temporarily dislocate local fish populations.

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With hydraulic dredging we are cutting materials and sucking it up and then pumping it to a holding cell,” Savin said. “You aren’t getting that large plume that disturbs (local life) as much.”

He added than any type of dredging also requires the temporary installation of turbidity curtains, or silk curtains, are temporary floating barriers used during inland lake dredging projects to contain suspended sediment and prevent it from spreading beyond the active work area.

Mechanical dredging involves the use of heavy equipment that often involves flipping muck into a dump truck. It is used more frequently with larger dredging projects because of the volume of work required, making it more affordable for large requests.

“Mechanical (dredging) is slower and more expensive for small projects. But it makes sense for most big projects,” Savin said.

When an inland lake is dredged in Michigan, the sediment removed from the lake bottom does not automatically go to a landfill. The material is typically evaluated to determine whether it is clean enough for reuse or requires special handling, according to the EGLE website. Sediment is often pumped into temporary containment areas or large dewatering bags near the project site, where excess water drains away and the material dries before being transported or reused.

Once dewatered, clean dredged material may be spread on approved upland property, used for landscaping or habitat restoration projects, or beneficially reused as fill. If testing reveals contamination or the material is otherwise unsuitable for reuse, it may be transported to a licensed landfill or other approved disposal facility.

The specific disposal method depends on the characteristics of the sediment and the requirements of the state permit issued for the dredging project, said Calabro.

Latimore understands that there is a need for lakefront property owners and associations to want to dredge an area to remove organic much to create water depth that allow boats to access a channel or homeowners to build docks. There are examples of dredging to remove pollutants or contaminants, which is a net positive for the lake’s environment. But Latimore feels it is important for property owners to remember the drawbacks. All types of dredging projects, including hydraulic, harm local lake ecosystems, he said.

For example, native plants and invertebrates will be killed during the dredging process. Other materials like silt will be suspended or displaced in the water, causing other issues. One such issue is that increased silt can make it hard for fish to breathe because small materials can get in fish gills.

While dredging rarely directly or indirectly results in an elimination of fish population, fish will vacate the area as soon as a disturbance starts, moving to other parts of the lake. Those fish are unlikely to return soon. Other livings organisms, including snails and clams, are not so lucky.

“Fish can just swim somewhere else but clams, which can be rare (in Michigan lakes) can’t,” Latimore said, adding that the clam population can completely disappear because of dredging. “Invertebrates and plants are also fish food, so the fish won’t come back there until (their food) returns. You will see a recolonization of the area.”

Dredging permit applications can be considered as either a major or minor project, Calabro said. Major projects would involve applications from marinas or commercial entities or permits that request a large area for dredging. Most of the permit applications are considered minor, since they may come from individual landowners and/or representative dredging consultants on behalf of their clients.

Once a dredging permit is submitted to EGLE, there’s generally at least a 30-day review period, although state statues may require up to 90 days based on the nature of the request before an answer is provided, Calabro said. It can also take several months based on the complexity of the application and the backlog of other permits.

The time of the year can impact how long it takes an application to be reviewed. Permit applications submitted in the winter may be reviewed faster because the backlog is often less.

“Everyone is thinking about (dredging projects) in the spring and summer,” Calabro said. “You want to work as far ahead as you can and anticipate when you may want to send in (a permit application). It may take even longer during growing or construction season.”

Spawning season will also impact not only EGLE’s review of an application, but the timing in which a dredging project may be allowed. Spawning season typically happens from March through the end of June. The Michigan Department of Natural Resources communicates the dates that incorporate spawning season with EGLE. The exact dates for a season can vary based on species, water temperature, lake and rover systems and the region of the state in question.

However, state regulators and fisheries biologists consider spawning season a restricted period for dredging, seawall installation and more because of the chaos it would create, which includes killing newly born fish and temporarily displacing adult fish populations.

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It’s a period (of the calendar) where we will pay close attention to the benefits of local fish,” Calabro said. Approved dredging permits outline months and weeks when dredging is allowed, and chances are approvals are limited at best during a designed spawning period.

Savin Lake Services handles inland lake and Great Lakes dredging projects of all sizes. One of its larger recent projects was Lake Shamrock in Clare, which included more than 150,000 cubic yards of dredging. The company also manages smaller dredging projects for one or more local riparian owners.

The Lake Shamrock project is considered a large project, which required mechanical dredging. Conception to completion of that dredging project took close to two years. Smaller project impacting one or a few riparian owners may only require a handful of onsite days.

Savin Lake Services handles an average of five to six “large” and 12-15 smaller dredging projects a year, Savin estimates. The company often has dredging projects in Oakland County, most recently completing one for a number of riparian owners in Pontiac Lake in 2025.

“It’s much better economically if you get multiple property owners involved for typical projects,” Savin said.

One of the biggest misconceptions about inland lake dredging is that projects can be neatly categorized by size and cost. According to Savin, every project is unique and must be priced based on the specific needs of the customer, site conditions, permitting requirements, and the volume of material to be removed. As a result, dredging costs in Michigan can vary dramatically. Savin’s company has completed relatively small projects for about $50,000, while larger undertakings have exceeded $3 million.

Savin has also prepared estimates for projects approaching $8 million and recently provided a preliminary estimate of roughly $200 million for an exceptionally large-scale dredging effort.

Before a contractor can even determine a project cost, many lake associations, municipalities, or property owners must invest in an initial bathymetric survey to establish existing water depths and calculate the amount of sediment that needs to be removed. These surveys typically cost between $2,000 and $5,000 and provide the data needed to estimate dredging volumes in cubic yards.

“We quote each project up front,” Savin said, noting that accurate measurements are essential to developing a realistic budget and ensuring customers understand the full scope of work before dredging begins.

He defined typical dredging projects as those likely to be approved by EGLE through the state’s permitting process, such as to dig channels, remove large amounts of muck and organics, managing weed control and more.

“Dredging is the quickest solution to rid your lake of muck and organic matter,” Savin said. “Riparian owners have a right to be able to navigate their waterways, so that’s the biggest reason we see.”

A dredging permit may not be denied or approved immediately, Calabro said. Some initial responses from EGLE may require clarification or corrections designed to avoid environmental impact as much as possible. That is why EGLE team members will generally conduct a site visit for each dredging application so they can get a sense of the local inland lake environment, including whether adjustments to the original application can reduce the environmental impact.

For example, lake bottomlands owners may ask to dredge a larger area of a lake than EGLE might deem necessary to successfully clear a boat channel or area for a new dock, Calabro said. Site visits also allow EGLE professionals to get a better sense of the impact of a proposed dredging on aquatic plants. The department may suggest or clarify the water depth needed to address a proposed need.

“There may also be less impactful alternatives to dredging, or a (scaling down) of a dredging project that is possible,” Calabro said.

The permitting process through EGLE can be tenuous, according to Savin, but firms his can submit the application on behalf of their customers and work with them in advance to improve the chances of a successful permit. Savin confirmed it can take 6 to 12 months for a small project to be completed from permit submission to completion, further emphasizing the importance of submitting in advance of a preferred completion date.

Savin said EGLE’s policies are designed to adhere to the ecologically “right way” to handle dredging, so that it maintains the best possible environment for local fisheries and organisms. EGLE must follow statutory criteria to find the least impactful alternative that allows property owners to gain access to the water for boating, swimming and other lake activities, Calabro said.

“We work with EGLE and understand what their requirements are,” Savin said.

Permit applicants can theoretically improve their chances of approval by turning in an application that provides detailed content outlining the reasons for a dredging request. Including photos of the area in question is highly recommended. In some cases, EGLE will determine that the photos and descriptions received from a detailed permit application are enough to render a decision without a site visit.

“We go onsite for all major (dredging application) projects and most minor ones,” Calabro said. “But a strong application with photos and a lot of information helps.”

Residents can also improve their chances of receiving a permit by working with EGLE in advance of turning in an application. Calabro said it is understandable that the typical applicant(s) may not understand all the factors that can be instituted to help minimize the adverse impact of dredging on a local waterbody. As a result, property owners can request a pre-approval meeting with EGLE through its MyEnviro webpage.

“We understand the application process can be intimidating,” Calabro said. “So, we’re here to help with that.”

The pre-application meeting highlights the collaborative nature that EGLE uses to help riparian owners. It not only breaks down barriers and educates applicants but can help the department to be more efficient in its dredging application review process, Calabro said.

“Our resources program on lakes, streams and wetlands is highly collaborative,” Calabro said.

While the process for securing a dredging permit is extensive, limiting dredging is often the best strategy, Latimore said. Dredging can also haven “hidden” drawbacks, compounding existing issues such as weed management or fish stocking, Latimore said. These activities can lead to a cumulative, negative impact..

“I think scale and timing are important,” Latimore said. The more residents are aware of the options for limiting the scale of a dredging project, the better. The best dredging project is not to dredge, but if you can’t do that you want to make sure to minimize the impact.”

Nearshore habitat complexity is extensive on inland lakes. Most habitat and ecological interactions in a waterbody are along the nearshore, Latimore said. Calabro agrees. Those nearshore activities and interactions, for all living organisms from insects to plants, are important to the ecological integrity of the lake.

“We don’t want to impair the ecological function of the (lake) just for the enjoyment of water for (residents),” Calabro said. He referred to dredging as an a “gouging of bottomland habitat.”

The impact of dredging on a lake can have similar comparisons to a forest fire that is maintained in a smaller area, Latimore said. Vegetation and animals/birds will return to an area impacted by a fire, but it will take a period of time, often a few years. “Lakes will be more barren for a period just like a forest will,” Latimore said.

Savin Lake Services has recently been contracted to handle several Great Lakes dredging projects as well because of consistently low water levels in the Great Lakes, caused in part by lower snowfall amounts in the winter. However, inland lake dredging projects are more common, Savin said.

In addition to working with riparian owners, Savin Lakes Services also works with lake associations, drain commissioners, local municipalities and more as dredging clients. The company can also work local municipalities under Public Act 188, which gives townships the authority to fund certain public improvement projects through special assessment districts that charge benefiting property owners for all or part of the cost.

“It often depends on the local governance who our client contacts are,” Savin said.

While EGLE is committed by statue to limit the environmental impact of dredging or other permits, the agency also takes significant priced in helping residents enjoy lake access while also adhering to shoreline protection policies.

“We also consider the impact to public trust and riparian rights,” Calabro said.

Dredging to depths of two to three feet typically is sufficient to address most of the issues permits are written for, Calabro said. New docks rarely require more than 10 to 12 feet of additional length. Cutting some aquatic plants may be an option as well. Calabro stresses that a minimal amount of dredging to solve an issue is always preferred.

“We want to design a project as close to as possible to a minor project category,” Calabro said.

Lakefront property owners can take a longer-term approach with dredging, Latimore said. Local land use, runoff activities, new developments, and the use of chemicals to treat grass or flowers can cause excess nutrients to enter the lake, resulting in the build-up of organic muck. Reducing those activities can limit the number of times dredging is needed. Latimore encourages lake associations and riparian owners to educate their neighbors on best practices.

“You want to ask yourself if you can get to a point where dredging isn’t necessary,” Latimore said. “It’s really more of a band-aid that can be (symptomatic) of larger issues.

The Oakland County Water Resources office is not responsible for overseeing inland lake dredging projects in the county, said Oakland County Water Resources Communications Officer Trisha Bruzek. Its involvement with lake-related activities is primarily through lake improvement boards, where a representative from Oakland County Water Resources serves as a statutory member as required under Michigan law.

“While we participate in those boards, individual lake improvement boards determine and oversee their own projects, including any dredging initiatives,” Bruzek said.

A significant inland lake dredging project is underway on Quarton Lake. The large project began in 2025 and is expected to be completed in 2029. The City of Birmingham awarded the project to Mid-American Group last year for the purpose of removing accumulated sediment and to restore lake capacity and water quality, according to Birmingham City Council meeting minutes.

Hydraulic dredging is being used for this project to pump sediment water into large geotextile dewatering bags. As the sediment dries and water drains, the sediment is eventually transported to a pre-approved disposal location, according to a July 2025 post on the city’s Facebook page.

Other lake dredging projects in Oakland County tend to be smaller and shorter, such as the one Savin referenced for Pontiac Lake riparian owners last year. “Once we get onsite we can have those completed in a few days,” he said.

The process of setting up a dredging project with a company like Savin Lake Services starts by defining the area that needs dredging in the eyes of the applicant(s), Savin said. Dredging typically can occur around 25-30 feet from the shoreline. Savin and his team will work with clients to then assess why the dredging is needed.

“We try to use hydraulic dredging where possible but there are times when we will identify if mechanical dredging is a better opportunity,” Savin said. For example, Lake Shamrock near Clare was a dammed lake. Dammed waterbodies often lead to more opportunities for silt settling.

The consultation with each client is very specific to their needs, according to Savin. His firm will provide recommendations that fall within the boundaries and requirements of EGLE. Often, they handle the entire permit process on behalf of their clients.

“Based on (more than 15 years of experience) we have insights we can share,” Savin said. “There’s a way to (have dredging) done that is responsible. That’s always our goal.” ­­­­­­