Reducing excess nutrients in a waterbody has proven to be an effective means of managing harmful algal growth and shifting the remaining algae population towards more beneficial species. Nutrients enter lakes and ponds from a multitude of vectors including watershed inflow, stormwater runoff and accumulated bottom sediment. As management practices are refined and better strategies are developed, successful nutrient remediation projects are a paramount part of an integrated lake and pond management program, with the ultimate goal being to sustainably manage internal and external nutrient vectors.
The most effective nutrient management and remediation programs are ones that limit external and internal nutrient loading. Performing low-impact design on a watershed can provide relief from nutrient-rich water from entering a waterbody, but that strategy has limits to its effectiveness. Excess nutrients introduced into the waterbody can recycle and cause annual impairment, even after watershed management strategies have been implemented.
As waterbodies age, it is common for small concentrations of nutrients to settle and become a part of the internal recycling of nutrients that gradually accumulates over time. As land-uses progress from undeveloped to agricultural to developed, the nutrients associated with each classification are incorporated into the landscape differently. Undeveloped areas offer the greatest nutrient management naturally, but that does not preclude them from impacting waterbodies; leaves and other assorted detritus can introduce undesired nutrients. Agricultural land, while fertile, can create nutrient-rich runoff which also introduces excessive nutrients into the water column. Runoff from developed areas can be detrimental to an ecosystem, especially when left unmanaged.
To help mitigate nutrients from entering developed waterbodies, shoreline buffers and low-impact design are two key practices that can be implemented. They both limit the nutrients that enter a waterbody by impeding the natural flow of water and allow for native emergent and wetland vegetation to process and utilize the nutrients. Local regulatory agencies can often impose design features to help mitigate impacts to wetland systems. These can include
establishing minimum setbacks, buffers and slope gradients, creation of stilling basins or retention ponds to allow stormwater runoff to percolate to the water table naturally, restricting fertilizers, and requiring samples to document inflow water chemistry. Recreation and waterbody use restrictions are additional measures to help passively manage nutrient loads.
Preventing nutrients from entering a waterbody is a noble goal, but if years of external impact might have occurred prior to the implementation of a nutrient management program, additional actions should be considered to help mitigate internal nutrient loading. A multifaceted management approach might be the most practical, implementing and creating shoreline buffers and low-impact designs while managing the nutrients in the pond that have accumulated over time.
Very few sustainable techniques for internal nutrient remediation are available, but alternative techniques have proven effective to help reduce the nutrient load established within a waterbody. There are numerous products currently on the market that have proven highly effective at binding with available nutrients and rendering them biologically inactive. They work by producing strong chemical bonds between the products and nutrient molecules. Another approach involves using aeration to increase circulation of the waterbody and oxygenation of the water column. By increasing the oxygen content of the water, microbial degradation of accumulated nutrients is increased, leading to lower nutrient concentrations. This modification of the water chemistry can also dictate the type of plankton that thrives. Augmenting the biological community with supplemental, naturally-found bacteria can further increase productivity.
Wherever a waterbody falls along the spectrum of eutrophication and nutrient loading, management techniques are available to be implemented and can help create a balanced ecological system.
Contact the experts at 888-480-LAKE (5253) for all of your lake, pond and fisheries management needs.
Matthew Salem is a Permit Coordinator and GIS Specialist at SOLitude. He helps educate clients on sustainable lake and pond management solutions and the effective management of their water resources. Matthew is proficient in reading and applying local regulations in order to balance regulators’ requirements and the client’s project objective, and has successfully assisted with the implementation of nutrient inactivation treatments throughout Massachusetts and Vermont.
SOLitude Lake Management is committed to providing full service lake and pond management services that improve water quality, preserve natural resources, and reduce our environmental footprint. Our services include lake, pond and fisheries management programs, algae and aquatic weed control, mechanical harvesting, hydro-raking, installation and maintenance of fountains and aeration systems, water quality testing and restoration, bathymetry, lake vegetation studies, biological assessments, habitat assessments, invasive species management and nuisance wildlife management. Services, consulting and aquatic products are available to clients nationwide, including homeowners associations, multi-family and apartment communities, golf courses, commercial developments, ranches, private landowners, reservoirs, recreational and public lakes, municipalities, parks, and state and federal agencies. Learn more about SOLitude Lake Management and purchase products at www.solitudelakemanagement.com.