Managing a pond is a difficult task — that’s even more complicated when it’s located on a golf course. When managing a water hazard, you not only have to consider the symptoms that are causing problems, the long-term health of the water, the environmental value and the functional value — you also have to manage for the golfers’ perceived value.
Ponds can be a source of backup irrigation water and a stormwater management feature, which will influence the strategy of a hole. They can also serve as a vital habitat for frogs, fish, songbirds and other desirable aquatic wildlife. From a visual standpoint, they often serve to relax golfers during a round. Rivers, streams and other bodies of water provide these same benefits.
For these reasons, it’s essential to properly maintain the ponds on your course. The keys to the development and continuance of their positive attributes are the utilization of proper best management practices and an awareness of local resources for assistance.
Pond construction and layout
Like most other issues on the golf course, the prevention of pond problems starts with good design and construction techniques. Many factors need to be considered before building a pond, including the intended use and size of the pond, water source, soil type, depth, capacity, slopes, water control structures, vegetation establishment, habitat enhancement, shoreline stabilization and environmentally sensitive areas, as well as permit requirements.
If all of these things are taken into consideration in conjunction with the goals of adding beauty and a fair challenge that will enhance the golfer’s experience while blending with other elements of the course, maintaining the pond can be enjoyable.
Although you have some degree of agricultural or horticultural knowledge, you may not have much knowledge in limnology (the study of inland waters). If this is the case, the first step is to contact an expert in limnology and develop a management plan together with an experienced water manager.
Ponds are ecosystems that have a series of relationships between organisms and other components within the system. Nutrients, such as nitrogen and phosphorus, can enter ponds through surface runoff after irrigation or a storm event. In most freshwater ponds, the limiting nutrient is phosphorus, therefore a small addition of excess phosphorus can easily lead to algal blooms and aquatic vegetation, as well as changes in turbidity, pH, alkalinity and dissolved oxygen.
Aquatic vegetation is often thought of as a maintenance problem, but plants are important to the pond ecosystem and provide many benefits, including:
stabilizing the shoreline and bottom sediments; and
adding aesthetic value to a pond.
However, excessive vegetation in ponds is a common maintenance problem. It’s important to first identify the vegetation. There are five major types of aquatic plants to watch for: algae, free-floating plants, rooted floating plants, submersed plants and emergent plants. They’re classified by their growing patterns.
Algae are primitive plants without true leaves or flowers. They can turn a pond into a green floating mat, make it look like pea soup, or even like there is paint on the surface. Free-floating plants, like duckweed and watermeal, aren’t attached to the bottom by roots, but float freely on the surface with the roots hanging down in the water and move with the winds. Rooted floating plants, such as water lilies, are attached to the bottom with their leaves floating on the surface. Submersed plants, including pondweeds (Potamogeton sp.), are rooted into the bottom and grow to the surface of the pond. Emergent plants are rooted in the pond bottom and extend out of the water. They usually occur along the shoreline and grow in water less than 3 feet deep. These include many familiar plants such as cattails, bulrush, sedges, smartweeds and arrowheads.
Preventive control methods
Many aquatic plants gain their start in a golf course pond by wind movement, flowing water, birds (particularly Canada geese) or fish introduction. By eliminating these sources and keeping the source of nutrients (often fertilizer) low, many of the excessive vegetation problems can be avoided.
Structural control methods
Rock riprap or pond liners can prevent rooted plant growth and limit nutrient exchange between the pond bottom and the water. Manipulating the water level in a pond by lowering it can control aquatic plants by drying them out or killing underground roots, bulbs or tubers. Dredging and deepening a pond is an intensive and expensive option, but is often the only way to remove a nutrient source and can remove nuisance plants.
Using dyes that stain the water to limit the amount of sunlight available to aquatic plants can help control plant growth, but may reduce fish productivity.
Aeration may lessen the severity of algal blooms by providing oxygen to the pond ecosystem, thereby allowing microbes to utilize the nutrients instead of algae.
In some cases, mechanical control through raking a
nd removal of the plants is an option, but may be a temporary fix as some plants will re-establish from the roots or plant fragments.
Biological control methods
Fungi, bacteria, insects and fish may be an option to control excessive vegetative growth. Grass carp can eat two to three times their weight in aquatic vegetation per day.
Barley straw at a rate of 225 pounds per surface acre of water decomposes in the pond, producing a chemical that prevents new algae growth, but doesn’t kill off what’s already present.
Chemical control methods
If vegetation problems exist following nutrient reduction and removal efforts, then chemical treatments can be considered. Typically, an entire pond does not need to be treated, but can be spot-treated along a shoreline or in a cove. If the entire pond needs to be treated, it should be done in stages, treating a quarter to a third of the problem area at a time and waiting approximately two weeks between treatments.
If too much of a plant is killed, its decomposition will use too much of the oxygen from the pond, which may stress or kill any fish.
It’s essential to remember that these chemicals will only be successful if you take the time to properly identify the weed that has created the problem.
Algaecides, including copper sulfate, copper chelate or endothol, are contact chemicals that can be used to control algae.
Endothol and diquat products are the most common chemicals used for submersed plant control. They work quickly (one week) and are short-lived. Eurasion watermilfoil may be more effectively controlled with chemical product groups such as 2,4-D, triclopyr or fluridone.
Diquat is labeled for rooted floating and emergent plants, but it only kills the foliage, not the plant. Glyphosate plus, a nonionic surfactant, is effective as a foliar spray or wipe-on treatment. Triclopyr, 2,4-D and imazapyr are systemic chemicals that may have varying degrees of impact depending on the species of vegetation.
Diquat can provide burn down control for free-floating plants, however plants usually grow back within a couple of weeks. Fluridone products provide effective control with proper usage.
Fish kills may occur as the result of lack of dissolved oxygen, poisoning or disease, all of which can be exacerbated by changing seasons and water conditions. Proper pond depth can prevent winter fish kills because of low dissolved oxygen. Aeration and water circulating systems may prevent other suffocation fish kills.
Many poisoning fish kills may be prevented by considering water health when selecting chemicals for turf maintenance and not applying immediately prior to rainfall.
Finally, by providing a healthy ecosystem habitat for fish, parasites and disease are less likely to cause fish kills because fish populations are healthy to begin with.
Ponds are best protected from shoreline erosion by establishing vegetation along the shoreline and utilizing hard armoring of the shore where necessary. Proper slope during design is also essential.
Although some water loss is expected in new ponds, if a pond is losing more than a foot of water per month and there is no withdrawal from a nearby well, you should look for a leak. Repairing a leaky dam or pond can be expensive. A bulldozer can be used to seal a pond. Bentonite can be spread over the bottom of a pond to seal holes, or a liner or rubber sheeting can be installed.
Unwanted pond animals
If you build it, they will come … the animals, that is. A pond will attract everything from snapping turtles to snakes to muskrats to frogs and geese. If your pond is properly designed and maintained, most wildlife will do little or no harm. For those that do become a nuisance, control is important for aesthetics, as well as for water quality and functionality.
Each region of the U.S. has different weed, fish and animal species and other water issues. A good method for finding answers to localized problems is to contact your local extension office or game and parks office.
Course management tips
- Contact an expert in limnology and develop a management plan together with an experienced water manager.
- Excessive vegetation in ponds is a common maintenance problem.
- Rock riprap or pond liners can prevent rooted plant growth and limit nutrient exchange between the pond bottom and the water.
- Using dyes that stain the water to limit the amount of sunlight available to aquatic plants can help control plant growth, but may reduce fish productivity.
- Aeration may lessen the severity of algal blooms by providing oxygen to the pond ecosystem.
- Ponds are best protected from shoreline erosion by establishing vegetation along the shoreline.
- Waterfowl are fun to watch but must be managed as well.
By John C. Fech and Katie A. Pekarek / contributing editors