Ponds provide drinking water for cattle and a fun fishing experience for children and grandchildren and they add value to property.
Neglect, though, leads to future headaches.
Aquatic Vegetation Management Program Specialist Brittany Chesser, with the Texas A&M AgriLife Extension Service, said a major component driving the success of agricultural lands is water and commodities that are dependent on available water quality and quantity for uses such as livestock watering and crop irrigation.
Texas has an estimated 1.3 million ponds. Most ponds were initially dug to serve as livestock watering “tanks,” specifically for cattle, to meet consumption rates of 15 or more gallons per head per day, she said.
However, more pond owners are realizing that their ponds can serve as a sanctuary for wildlife and a place for recreational activities, like fishing with family and friends.
Chesser is the lead diagnostic scientist at the Aquatic Diagnostics Laboratory at Texas A&M in College Station, Texas. Basic water quality, which also plays into unwanted algae blooms and other aquatic vegetation issues, is the main challenge, she said.
“Once built, ponds can go years before there is an obvious problem. Pond owners think their pond is relatively low maintenance the first few years and when a problem shows up they say they are still implementing the same management practices, so what gives?” Chesser said. “Ponds are nutrient sinks, which accumulate nutrients from the watershed over time. They should be evolving their management strategies to fit their pond constantly evolving.”
In spring, owners should check their ponds often and stay proactive in management rather than taking a reactive mode to prevent aquatic vegetation. Common techniques include:
• Deepen pond edges to 2.5 to 3 feet deep to reduce the amount of area the sun will be able to penetrate to the pond bottom and minimize vegetation that can occur.
• Fertilize the pond to limit sunlight from reaching the pond bottom.
“This is both similar and different when compared to fertilizing a lawn,” Chesser said. “However, for pond fertilization you are looking to use an inorganic fertilizer that is high in phosphorus, which is the limiting nutrient in a fresh water body.”
Phosphorus enhances the natural food chain in the pond by providing food for phytoplankton, which also increases dissolved oxygen through photosynthesis. The initial application should begin when water temperature is between 60 and 65 degrees Fahrenheit when aquatic plants are not present. If fertilized too early and temperatures dip below the threshold, phytoplankton will die off. If fertilized too late and aquatic vegetation is already present, it will make the problem worse by adding nutrients. Smaller applications can be applied to a maintain 18 to 24 inches of water clarity as needed through September.
• Using a dye can also shade the pond bottom like fertilization but is not usually recommended for fish ponds because it does not enhance the natural food chain and may actually cause larval fish to be stunted. There are many dye colors available for ponds that may be more aesthetically pleasing than a traditional pond, such as blues, greens, reds, browns and even black.
“In the spring, aquatic vegetation will begin to explode, ; it may seem obvious but treat when an infestation is small,” Chesser said. “Before they know it, their pond will be covered and the water temperature will be too high for them to safely treat.”
Additionally, spring is the time to stock herbivorous fish such as triploid grass carp or blue, Nile, Mozambique and Wami tilapia to help control other aquatic pests. Pond owners should consider testing their pond water at least once per year especially before they stock their ponds with fish or make any amendments such as stock salt, ag lime or clearing treatments.
Conserving, preserving water quality
Ponds can experience heavy water loss due to evapotranspiration from aquatic plants and they should be controlled when possible, Chesser said. Some aquatic plant species like water hyacinth, cattails, giant reed, and nutsedge can double or triple water loss. To put it into perspective, most counties in Texas have an average of 50 to 60 inches of surface water evaporation per year, which is roughly 5 feet of water. Also, removing any aquatic plants like willow (Salix nigra) that may contribute to dam failures or leaks is a good idea.
Algae and weeds, particularly from stagnant water, can be a common problem. Chesser offered these tips:
• Establishing a 10- to 20-foot buffer zone around the pond with native vegetation to filter excess nutrients;
• Decreasing the amount of fertilizer used near the pond, especially before rain events;
• Preventing livestock from defecating in or near the pond;
• Locating septic fields far away from ponds;
• Managing nutrients and bacteria; and
• Using aeration to disturb stagnant areas.
Testing the pond water can be a proactive approach, the lead diagnostic specialist said. Color disk or titration kits for farm ponds run around $300 to $400 and will typically work for a basic water chemistry analysis.
“This may or may not be feasible for pond owners to do themselves,” she said. “The biggest issue comes into play when the results are in and need to be interpreted.”
Basic parameters like pH, hardness, alkalinity and chloride concentration can aid in pond management decisions dealing with aquatic plant management, fertilization applications, parasite or disease management and pond clearing techniques, and they can also be a good indicator of overall pond health.
More specific testing often requires multiparameter meters, which usually start off above $1,000 for a dependable handheld meter, not including reagents for particular tests, and some equipment may require frequent calibration.
If a landowner’s goal for their pond is primarily fish production, they may be considering a dissolved oxygen meter, which may not be necessary, Chesser said. Reliable meters start at $500. By detecting a lower dissolved oxygen concentration, they be may be able to correct for it, for example, adding emergency aeration, before it is too late. But without a meter, there are other indications like fish gulping air at the water’s surface that the pond owner can look for in earlier morning hours, when oxygen is at its lowest.
Oxygen depletions account for about 85% of all fish die-offs in Texas farm ponds, she said.
“This is typically seen in the hot summer months because warm water cannot hold as much oxygen as cool water, and fish oxygen requirements are already increased,” Chesser said.
Additional information on fish kills and correcting for low dissolved oxygen can be found at http://agrilife.org/fisheries2/files/2013/09/My-Fish-Are-Dying.pdf.
Expansion thoughts
Before expanding pond, Chesser said owners should assess their overall management goal and whether expansion will detract or add to that goal. Generally speaking, smaller ponds are easier to manage.
With any type of pond construction or maintenance, soil science and civil engineering are heavily involved. If they need help, they will need to contact their regional Natural Resources Conservation Service office for a list of contractors and specialists.
Other items
The top practice for owners is to frequently inspect their pond.
“Another practice is to properly identify the issue. Do not blindly try to manage either an aquatic vegetation or water quality issue,” she said. “This could result in thousands of dollars lost due to the selection of an ineffective management strategy. Many times a pond owner will not reach out to their local county Extension agents until they are realizing that their initial treatment did not work.”
Some owners have upstream feeder ponds and those also need inspection to avoid the wrong types of vegetation or fish entering the main pond.
Unfortunately, if they do not own the upstream feeder pond and it is being neglected, the only thing they can do is be on the lookout for new vegetation and fish entering their pond. Floating aquatic plants, like duckweed and watermeal, can easily travel from ponds upstream and take over a pond rapidly. Once established, these plants can clog outflow pipes and limit sunlight entering the pond, which can cause dissolved oxygen issues. If not managed quickly, it can be a very expensive problem. The same could be said for fragments of submerged plants, like coontail and hydrilla.
Ponds can serve dual purposes to water livestock and provide fish habitat.
“Limiting access to a single or few watering points for livestock and placing large cobblestone in these access points can also decrease wading time and erosion, and reduce the suspension of clay particles and nutrient concentrations, which will improve overall water quality and overall reduced wading has improved livestock benefits.”
Good vegetation can help filter water as it flows. A mixture of species but native grasses with deep, complex roots will stabilize the bank, filter nutrients and slow down water runoff the most, she said.
Most of the species like bulrushes, sedges and cattails have great bank stabilization but can or will get out of hand and cause other issues, requiring management down the road. But this will be common with most aquatic vegetation.
Chesser manages AquaPlant and that is where new online courses and live webinars are posted at https://aquaplant.tamu.edu/.
Dave Bergmeier can be reached at 620-227-1822 or [email protected].
Pond problems
