Pond management and maintenance can be a tricky process in a perfectly controlled environment. Add in fluctuating temperatures and rainfall, and it can be a nightmare. There are several key things to keep in mind that can help you keep your ponds healthy and a fun place to be this summer.
Depth is one of the most important and, most likely, the hardest to alter. At least a quarter of your pond should be 8-10 feet deep. This will help to keep your fish from being susceptible to winterkill by providing a temperature buffer and will help discourage aquatic plant growth.
Keeping the depth on your pond can be difficult as most of our eastern Kansas water bodies are extremely susceptible to sedimentation. It’s important to keep an eye on the water flowing into your pond and working to pull the sediment out of the water using grass buffers and other methods to prevent your pond from filling in.
Keeping the water moving through either a current or a bubbler is beneficial for many reasons. Dissolved oxygen in the water is what fish need to be able to respire. It is also what keeps the environment from becoming purely anaerobic. When a pond is stagnant and anaerobic is when that funky smell comes into play. A stagnant and non-moving water body is also great habitat for mosquitoes. Keeping the water moving and healthy will prevent a mosquito population from getting out of control.
Dissolved oxygen also plays a role in the life cycle of nutrients in the pond, which brings us to our final consideration.
It’s no secret that nearly every water body in eastern Kansas will have fairly high levels of nitrogen and phosphorus. This comes from the runoff of our agricultural and landscaped lands. Fertilizers are used for high levels of vegetative growth, but not every bit of fertilizer is utilized by the plants. A fair amount of it is captured by runoff from our rain events and moved into our rivers, lakes, streams, and ponds.
This has a large impact on algal blooms and other plant life within our ponds. Algae and other water plants use photosynthesis for their energy production. They use sunlight, carbon dioxide, and water. Excess amounts of nitrogen and phosphorus in the water causes algae and other water plants to overproduce and throw off the natural balance. The now extraordinarily large amount of decaying algae and plant matter overwhelm the bacterial decomposers, cause a lack of oxygen in the water, and can lead to the death of fish and other animals dependent on oxygen in the water. This is what is known as eutrophication.
Eutrophication is most easily seen in our lakes and reservoirs that are used for recreation. If you’ve ever had your lake plans cancelled because of a Harmful Algal Bloom, sometimes referred to as an HAB, then you’ve been impacted by eutrophication. Blue green algae (the organism behind an HAB) is toxic to humans and other humans if ingested. It’s important to keep an eye on our ponds and lakes used for human recreation and consumption as algae can have a big impact on human health.
How do we control algal blooms and other vegetation from growing beyond our control? This can be tricky. It all comes down to the nitrogen and phosphorus in our waterways. Only apply fertilizers which are needed to your agricultural land and landscaped areas. You can find out if you are over applying by running a soil test. Our office provides a free soil testing program, for county residents, which can help you determine this. Make sure if any runoff is coming into your pond it is running through a minimum of 10 foot wide grass buffer. This not only helps keep sediment from reaching your pond, but can also help reduce the amount of nutrients reaching your pond. And don’t mow the lawn clippings into the pond, either.
Keeping a healthy pond is not an easy task, but can be incredibly worth it. They can be the center of summer fun with the family, and can provide many years of enjoyment if taken care of properly. Some parts of managing a pond can be expensive or difficult, and others can be a function of altering your fertilizer application on surrounding land.
For more on ponds, check out our website for more in-depth information at: https://www.johnson.k-state.edu/natural-resources/pond-management/index.html
The Kansas Department of Wildlife, Parks, & Tourism also has some great information on considerations for building a new pond that can be found here: https://ksoutdoors.com/Fishing/Special-Fishing-Programs-for-You/Pond-Management-Program/Producing-Fish-and-Wildlife-in-Kansas-Ponds/Pond-Construction-Consideration