Managing Aging Lakes & Ponds

One of the most basic but most valuable tools in freshwater management is water quality testing. Like a blood test, aquatic experts analyze dozens of factors to establish a baseline of health, identify potential areas of concern, and develop a treatment regimen as needed. Parameters like dissolved oxygen (DO), turbidity, total phosphorus, and temperature can reveal a lot about what’s going on beneath the surface. And by tracking these parameters over time, lake management professionals can identify trends and predict what may be in store for your waterbody in the coming months and years.

For example, falling DO levels can indicate that the environment is becoming less hospitable to aquatic life. This is particularly common as temperatures rise in the summer as the solubility of oxygen decreases. Fish, beneficial microorganisms, and native aquatic plants require oxygen to survive. Without intervention, fish kills and die-offs may be in your waterbody’s near future. But when caught early, floating fountains, surface aerators, submersed aerators, and oxygen saturation technologies like nanobubbles can be introduced to increase DO and circulate it throughout the water column.

Rising phosphorus levels may suggest that the rate of eutrophication is accelerating. Getting to the root cause of this increase is important to halt and even reverse the degradation of a lake or pond. For example, nutrients may be entering the waterbody via stormwater runoff. During storms, rainwater flows across impervious surfaces, picking up nutrient-rich sediment, trash, animal waste, and yard debris before it flows into stormwater ponds. 

In addition to nutrient remediation, professionals may recommend completing a bathymetric mapping study to evaluate depth levels and monitor for underwater signs of aging. During a bathymetric study, hundreds of data points are collected to map the bottom of the waterbody, revealing the unique depths and contours. When conducted on a recurring basis, bathymetry can reveal the areas at most risk of sedimentation and help estimate future sediment removal needs. With an accurate timeline, stakeholders can properly budget and prepare.

Shoreline erosion may be another sign that your waterbody is aging. As sediment deteriorates into the water, it contributes to the formation of a layer of nutrient-rich muck on the bottom that reduces the waterbody’s depth and capacity to hold water. Without intervention, costly dredging will be required in the future to physically remove accumulated sediment and restore the waterbody to its original form. 

Ultimately, dredging is in every waterbody’s future if not properly managed. But every waterbody is unique and requires different maintenance techniques to not only prolong the need for dredging, but to also reach its full potential as a recreational lake, stormwater pond, or aesthetic focal point. Through an Annual Management Program, aquatic experts keep a watchful eye out for signs of functional and water quality problems, and get ahead of them through preventative solutions – so stakeholders can get a lifetime of use and enjoyment from their water resources.