Golf course maintenance is a business where the smallest details matter. But so, too, do the big ones. You can fill every divot hole, rake every bunker perfectly, smooth every bump on every green – but if the pond on your golf course (possibly the largest and most visible feature on the layout) is a stinking cesspool of filth, golfers are going to notice that first.

Because of the prominence of ponds on golf courses, many golf course superintendents put a premium on making sure the surface is clean, so that it looks good, says Roy Watkins, president of Air-O-Lator. Unfortunately, that doesn’t always mean the pond is actually healthy, and continually treating the pond with chemicals to kill off weed growth may actually just mask the problem.

“The underlying problem is that the pond is lacking oxygen,” Watkins explains. “So the number one thing superintendents should do is aerate.” But, he notes, many golf courses today don’t want to put in any surface-type unit, whether it be a fountain, a surface aerator – anything that takes away from the “natural look” of the pond.

“Well, if you don’t aerate and you don’t do anything to it, it will look natural, which is a mess.” Watkins says.

There are low-profile surface aerators available that only spray about 18 inches in the air, but many superintendents turn to chemicals, which are just a Band-Aid – a quick fix to take care of the visual component of the pond, but won’t deal with the underlying problems that may be going on in that body of water.

“A pond is a living ecosystem. There’s all kind of things going on in there,” Watkins says.

It isn’t enough to focus on beautifying the surface of a pond, Watkins adds. For example, if you kill the algae or plant material that’s on the surface of the pond, it will just sink to the bottom and form sludge. “It will decompose; there will be higher nitrates, more nutrients, then the next year it may take several chemical applications to keep the pond looking good,” he explains.

Worse, says Watkins, if the pond is supplying irrigation water for the course, that water may be harmful to the turf: “Bad water equals bad turf – whatever you’re putting in that pond is what you’re going to be spraying back out on your greens.”

Renovation required

“We typically get called to a pond only after there’s a significant aquatic weed or algae problem,” says Carla Ott, president of pond and lake management company Otterbine-Barebo. She says that the decision about whether a renovation is necessary is then made based on the overall health of the pond and its age. So the presence of weeds, by itself, does not mean a renovation is required. “You may just have an algae or aquatic weed problem … we can than put an aeration system in, or a chemical program, or both, that would satisfy the needs of the pond,” Ott explains.

So when is a renovation required?

“It’s when you have year after year after year of a pond that has a lot of undergrowth of weeds – bottom-rooted weeds – or there are algae on top of the pond that is present, it rains, the algae sink to the bottom, the algae grow, it rains, the algae sink to the bottom – all this creates a really significant bottom layer of sludge,” Ott says.

Before

PHOTO: AIR-O-LATOR

“The pond basically begins to grow in and become more of a wetland than a pond.”

This process can take place over the course of a couple decades; eventually, when the pond gets to a depth of less than 6 feet, there’s not enough oxygen and too much carbon dioxide present, and a pond renovation is really needed, she adds.

The purpose of renovating, or dredging, a pond is to deepen it and remove the sludge from the bottom and create a healthier environment. Leaves falling in the autumn, grass clippings, weed growth, waste from geese and ducks, blowing dust, and runoff from rain and snow-melt – these are some of the key ways that a pond begins to fill in, says Brian Pirl, vice president of operations at U.S. Aqua Vac. “Everything seems to go to the lowest point, and the lowest point is the pond,” he states.

Over time, sediment builds up, at an average rate of about 1 to 2 inches per year, says Pirl. “So after 10 years, you could have 1 to 2 feet at the bottom.” As the build-up occurs, it starts to create sandbars and kills off fish, while depleting the pond of oxygen, which furthers weed growth. Basically, the pond is strangled from the bottom, says Pirl.

After

U.S. Aqua Vac is one company that conducts pond inspections; it provides a written report to superintendents about, among other things, the amount of build-up at the bottom of the pond, though Pirl says some superintendents take on the job of measuring that build-up themselves. The key is not to wait too long to take action. At that point, a renovation is more difficult – and more expensive.

“It’s much less costly to catch things early. To remove soft sediment under the water is about 10 times faster than removing a concrete-hard sandbar that’s up on top of the water,” Pirl explains. “We can still do it at that point, but it’s much more costly.”

Action afterwards

“A renovation really gets you back to square-one,” says Pirl. “It’s as if the pond was brand new. It gives you a chance to start off clean; at that point, it’s always a good idea to do the right things, like regular pond treatments and putting in an aerator.”

These are the steps that will help you delay and avoid the need for another pond renovation in the future.

“The number one thing that a superintendent should do is start some sort of pond management program that must include some type of aeration,” says Watkins with Air-O-Lator.

There are various mechanical surface and subsurface aeration options, but the goal is the same: to get oxygen into the water. Watkins encourages superintendents to run their aerators especially after sunset; plants produce some oxygen from the sun during the day, but oxygen levels in the pond really drop at night. This is a good option at courses concerned about the appearance of mechanical aerators when golfers are around.

The next important thing is mixing, he says.

“You want to have a device that is going to create mixing throughout that body of water. You can aerate, but if you’re not moving that water around, you’re not going to disperse that oxygen.” Plus, he adds, algae don’t like movement, which acts to break it up.

In addition to keeping grass clippings and other debris out of the pond, you can create a zone around the pond that’s fertilizer-free, suggests Ott with Otterbine. She says there are also “shelves” that can be installed at or just below the water level around the circumference of the pond; maintenance companies can then install specialized plants on these shelves – sometimes even in containers – to help capture some of the chemicals that would otherwise enter the pond with runoff and help the pond grow weeds.

She also emphasizes the need for a top-notch aeration system to promote plenty of circulation in the pond, like good bottom-to-top mixing to prevent stratification, and thus help prevent the regrowth of algae. This is both easier and cheaper than a repeat renovation.