Lake & Pond Dredging

Many lake and pond managers do not recognize the complex nature of their aquatic ecosystems. Our waterbodies are constantly changing and, in a sense, aging. Over the course of two to three decades, they begin filling in with sediment and debris due to both natural and man-made forces (just like a newly dug hole will eventually fill in). This results in loss of depth and volume, flooding, nutrient loading, and other concerns that further expedite the decline in aquatic health.

The term “dredging” may mean different things to different people, but ultimately refers to the removal of muck, sediment, detritus, or organic matter from the bottom of a waterbody. This management method is used to restore depth and volume, as well as remove excess nutrients and pollutants from the ecosystem.

Dredging projects are expensive, unsightly, and inconvenient, which can have rippling effects, particularly in HOAs, apartment complexes, and other communities. It is all too common for stakeholders to raise dues and fall short on other community upkeep efforts in order to fund a dredging project. This can lead to complaints, drive away residents, threaten a community’s reputation, and create shocking financial risks.  

Because most stakeholders have little idea how much it will cost to dredge a pond—or that they need to dredge one at all—they don’t begin budgeting soon enough. In fact, many stakeholders have zero funds available and must take out considerable loans or save for several more years, all the while watching the continued decline of their waterbody. This tends to be the case when action is not taken until problems have already passed the point of no return.

State-of-the-art dredging equipment is designed to endure difficult environmental conditions. Premium insurance and diligent maintenance throughout a project is necessary to ensure excavators and tubes stay in optimal condition. Dredging companies also utilize costly specialized spill kits that absorb any fuel leakage to prevent water contamination. 

Dredging projects are very labor-intensive and require highly-trained professionals. Typically, 4-6 experts are on-site for the entirety of the project, which can take 1-3 weeks or more to complete. Costly licenses and certifications must be maintained in order to operate the equipment. 

Before mobilization begins, professionals carefully work out project logistics, but there are many unknowns that simply cannot be accounted for. For example, unexpected rainfall can cause equipment to sink into bottom sludge and get stuck. Uncovering clay or plastic liners during the process can make restoration efforts more difficult. These and many other unpredictable events may require pivoting and additional funds. 

When planning a project, professionals start estimating lake dredging costs by determining how much material needs to be removed and what the material is made of. Measuring the level of build-up can be challenging, so dredging experts rely on bathymetric mapping to create a three-dimensional model of the waterbody that reveals depth, bottom contours, and highly-accurate volume calculations. The average project removes around 4-6 ft of muck, and on some occasions 8-10 ft or more! Prices can increase dramatically in correlation with muck depth. 

Material composition is important because it guides the type of equipment used for the job. Sandy, gravelly materials dry out much faster than muck and sludge. “Soupy” materials must be handled and disposed differently than dense substances. 

When dredged materials are deemed too watery, they may require dewatering prior to removal from the site, adding additional costs to the project. Expensive geotextile dewatering bags and specialized dewatering tanks allow water to seep out; however, this process can take a few days to many months depending on material composition and how much was removed. 

Furthermore, the outer layer of decomposing materials often hardens into a shell that locks in moisture. To keep the drying process on track, professionals must return to the site on a regular basis to turn over the saturated piles, increasing the overall cost to dredge a pond.

Once the drying process is complete, the materials are typically removed from the site for disposal. While this may seem like a straightforward process, complex regulations dictate where, when, and how materials can be disposed of. These regulations can vary by state. 

Before material disposal, laboratory tests must be conducted to identify the presence of metals and contaminants. Depending on the results, landfills may impose additional fees to dump the material. Environmental hazards are surprisingly common in lakes and ponds, particularly those near construction and urban development sites.

The presence of invasive plants or animal species like quagga mussels can add additional challenges and increase the cost to dredge a pond. Depending on the situation, invasives may need to be managed before a dredging project begins, as well as thorough equipment and material inspections prior to disposal. This prevents spread into other ecosystems across the region. 

To cut lake dredging costs, stakeholders can choose to dispose of dredged materials themselves. Clients with several acres of land may be able to transport materials to designated areas on their property without concern for drying. However, compact properties or those in metropolitan areas face additional challenges and inconveniences when choosing to dispose of materials on their own. 

Landfills will charge significantly higher rates if materials are too saturated with water. This means the longer that stakeholders dry out their materials, the more money they can save. Unfortunately, this also means that dredged materials must remain on-site for weeks to months, creating an eyesore, damaging grass and landscaping, and releasing bad odors from decomposed organic materials, dead fish, and animal feces. Clients may purchase deodorizers to inhibit unpleasant smells, though this requires additional funds.

No matter the method used, dredging is messy and can cause significant environmental stress by displacing native wildlife, interfering with the natural processes, and releasing hazardous materials from the soil. Reputable companies often consult with environmental firms and the US Army Corps of Engineers throughout the entirety of a project to monitor and mitigate environmental risks, including the downstream impact.  

Certain projects may require special permits, which can be particularly complicated and costly to obtain. Permits can also be revoked in the face of new weather conditions or project delays, further impacting the project budget.