Whether you are a lake manager, part of a lake association board, or even a dockmaster, there is a lot that goes into the care and keeping of your lake – and a lot of information that goes along with this.
But what information do you need to collect and track? What data can you use for predicting upcoming issues or what treatments you may need? And how do you even go about collecting this data?
Today, we are walking through exactly this. Starting with what information you should be keeping track of, what it will help you predict, how it informs strategies for years to come, and how to get this crucial data (and recommendations) in hand.
Water Quality refers to the overall condition of the water within a pond, lake, stream or more as derived from chemical, biological and physical characteristics. At Clarke, some of the tests our team recommend include, but are not limited to:
- Secchi Disk: A Secchi disk test is used to measure the clarity – or turbidity – of water. The actual disk is lowered into the water until it is no longer visible. This depth is measured and known as the Secchi depth.
- Phosphorous: Phosphorus is one of the key elements needed for plant and animal growth, and a lack of it can inhibit growth throughout a lake’s ecosystem. Phosphorus is often scarce in well-oxygenated lakes, and low phosphorus levels limit the production of freshwater systems.
- Nitrogen: Total Nitrogen is an essential nutrient for plants and animals. However, an excess amount of nitrogen in a waterway can result in low dissolved oxygen levels and negative impacts on plants and organisms. Sources of nitrogen include wastewater treatment plants, runoff from fertilized lawns and croplands, failing septic systems, runoff from animal manure and storage areas and industrial discharges that contain corrosion inhibitors. The three forms of nitrogen commonly measured in water bodies are ammonia, nitrates and nitrites.
- Chlorophyll-a: Chlorophyll-a is a measure of the number of algae growing in a waterbody. It is used to classify the trophic condition of a waterbody. Although algae are a natural part of freshwater ecosystems, too much algae can cause aesthetic problems such as green scum and bad odors as well as decreased levels of dissolved oxygen.
- Harmful Algae Blooms (HABs): HABs are overgrowths of algae in water. Some produce dangerous toxins in fresh or marine water, but even nontoxic blooms hurt the environment. Nutrient pollution from human activities makes the problem worse, leading to more severe blooms that occur more often. Harmful algal blooms can be green, blue, red or brown. They can be scummy or look like paint on the surface of the water.
- Microbial Bacteria Identification: coli is a fecal coliform bacterium specific to fecal material from humans and other warm-blooded animals. EPA recommends E. coli as the best indicator of health risk from water contact in recreational waters (USEPA 2006).
By keeping track of these characteristics and implementing periodic testing, property managers, lake associations and harbormasters can stay ahead of HABs, fish kills, plant overgrowths and other harmful conditions that are costly, timely and difficult to eradicate.
These are a lot of key water quality parameters to track. Aquatic services companies, such as Clarke, can provide these tests on a periodic, timely basis and provide recommendations and adjustments as may be needed.
As discussed in the above section on Water Quality, aquatic plant overgrowth can have detrimental impacts on any type of waterbody. You can read more about what aquatic plants are, a native one versus invasive one and some common examples in Clarke’s Guide to Aquatic Plants.
There are a lot of benefits to having native aquatic plants in your lake and pond. Plants are a critical part of keeping a water system balanced – they help improve overall water quality, provide oxygen, enhance fish and wildlife habitats and create shorelines and littoral areas that serve as filters for detrimental runoff.
Yet, overgrowth of native species and the presence of harmful invasive species can be catastrophic to a lake or pond ecosystem – its native plant community, fish populations, recreational use and property values. Their growth and subsequent decay can also contribute to algae and HABs.
Other factors that impact the health of aquatic plants include:
- Recreational Use (Boating, Fishing, ect.)
- Rainfall and Runoff
- Nutrient Load
- Water Depths and Clarity
- pH Levels
It is also important to have a firm understanding of the wildlife – fish, waterfowl and other animals – within your waters. While the immediate benefit that may come to mind is good fishing, the presence of a balanced fish population also helps keep weed, algae and invertebrates at bay.
A lake should have a healthy, thriving fish population which requires some care to maintain a balance. For example, you will want to keep a balance between predator fish and the prey fish they feed upon – a common rule of thumb is three prey fish per predator. Having this structure allows the prey fish an opportunity to reproduce.
Some of the other factors that go into a balanced, healthy fish population include:
- The size of each fish
- Introduction of new fish/building populations
- Timing of restocks
- Acclimating new fish
- Providing diversed habitat
- Ensuring water quality levels – especially dissolved oxygen – are maintained
The foundation to any of the above needs to include a fish survey. This will ensure that you have a comprehensive understanding of what fish are already in your lake or pond, their health, their stage of maturity and opportunities for new species and their amounts to introduce.
At Clarke, we provide fish and biomass surveys, electroshocking and fish stocking as part of our overall water quality offerings. Contact a rep here to get started on a strategy for your lake’s wildlife.
Soft Sediment Analysis
Soft sediment refers to the buildup of muck – loose sand, clay, slit, decaying plants and other loose particles – from erosion or decay accumulation. Erosion happens naturally, the fate of all waterbodies is to fill in to an extent – but nearly 70% of erosion is a result of human activity.
As sediment accumulates, it can:
- Clog storm drains and catch basins (increasing potential for flooding)
- Disrupt water flow and destroy fish and wildlife habitats
- Decrease water depths and inhibit the recreational and commercial use of water
You can find more information on the detrimental effects of sediment accumulation from the EPA.
Because of this, it is essential to be aware of the structural integrity of your lake or pond bottom. A sediment analysis – mapping done to locate areas of different sediment types paired with manual surveys to determine the makeup of said sediment – will allow you to remain ahead of any potential issues, work to combat human-related acceleration and plan for any potential future needs.
Some of the benefits of lake sediment hardness mapping include:
- Planning and budgeting for sediment removal / dredging
- Determining the stability and composition of lake bottoms for structures such as docks
- Implementing sediment / debris filtration practices
You can learn more about how the sediment analysis process works in Clarke’s Guide.
Bathymetric mapping surveys the contours and depths of a lake or other waterbody. In the case that your lake has a contour map from the 1950s, 60s or 70s, it would be wise to have an updated map utilizing modern GPS-integrated depth-sensing technology.
Some of the benefits of lake bathymetric mapping include:
- Properly choosing, sizing, and placing an aeration system
- Mapping the waterbody for boat navigation, fish restocking, and more
- Using volume levels to determine types of herbicides needed to treat aquatic vegetation and algae given EPA regulation
Learn more about bathymetry mapping and Clarke’s integrated approach here – our team is proud to use state-of-the-art equipment such as BioSonics to ensure our clients have the most accurate, detailed information possible.
Fountains & Aeration Equipment
The final information to keep track of concerns any fountain and aeration equipment you may have on-site. You can learn more about the many, many benefits of utilizing aeration and increasing the amount of dissolved oxygen (DO) in your waterbody here.
There are three main types of aeration equipment, each with its own purposes, capabilities and needs.
- Floating Commercial Fountains and Aeration Diffusers: These are what most likely first come to mind, the aesthetically appealing fountains that typically spray water up and out of the pond or lake. These also do a good job of improving DO levels and enhancing overall water quality, although they do not cover the entire water column. They do need to be removed during the winter and reinstalled in the spring – a service Clarke provides.
- Sub-Surface Aeration Systems: Sub-surface systems aren’t as visible as they sit on the bottom of a pond or lake, pulling water from the surface via hoses and pumping it out into the water. This helps increase DO levels and circulate water from the bottom up. They can stay in the water year-round with proper winterization, which helps to prevent fish kills and other negative factors in the spring.
- Deicers: For cold weather climates, deicers can prevent ice damage to permanent docks and create open water access for fish habitats. Deicers frequently attach to a dock and keep surface water circulating all winter to prevent freezing. Learn more about how deicing works here.
Working with Clarke
Our experts at Clarke have years of experience working with a vast variety of lakes and communities, with a focus on catering to their unique needs and goals and an emphasis on using science-based techniques and technologies to do so. To learn more, contact our team here, or check out other articles such as