Building a Pond: Time and Design Considerations

Angela Hopko
November 1, 2011 — 1,384 views  

When pondering how to rejuvenate a landscapes, what better way to do so then to create life by installing a pond which will eventually support an entire ecosystem?

Building a pond continues to be a strong trend in the landscaping industry and for good reason. Not only do water features raise the value of a property both aesthetically and commercially, they also offer a wide range of functions from irrigation and drainage purposes to encouraging an ecosystem and wetland mitigation.

The installation and maintenance process of a pond will be inexpensive, virtually maintenance free and relatively easy if the proper amount of planning is done at the right time...which is now. Here are the basic questions to address and guidelines to follow when planning:

What function is your pond going to play?

Any water feature has the role of a truly unique landscape element. It also has the ability to capture anything- whether it be your attention or run off, as seen in the four most popular types of man-made ponds:

Retention: Depending on where your pond will be located, no doubt it will receive run off anywhere from fertilizers and grass clippings to parking lots to farms. As many of us know, run off can do great damage to turf. To collect these harmful nutrients, a retention pond is strategically placed in an area that is most likely to be the collecting point of excess water. This spot is usually the lowest part of your property or at the bottom of a slope. After the contaminated water is received, retention ponds do not distribute the water back into the ground, rather they, well, will retain it. Eventually, through nature's own processes, the water gets recycled back into the environment.

Be aware that this type of pond overtime is the most susceptible to obtaining very high contents of harmful nutrients such as sulfur and iron unless maintained properly.

Detention: Like the retention pond, a detention pond is skillfully designed and situated for the purpose of collecting excess nutrients and run-off. However, this type of pond does not retain the water, rather it distributes it back into the soil through a drainage system.

Decorative: Like its name suggests, a decorative pond's objective is to attract and please its viewer's senses through its serene placement and relaxing resonance. Usually built in areas that do not have a high amount of run off, this type primarily acts as a compliment to a setting.

Water Hazard: Almost always built in golf courses, the sole purpose of this type is to act as an obstacle to golfers

Where are you going to put the pond?

Most likely, after you have determined the purpose you wish your pond to assume, you will have a better focus on where exactly to place it. Consider the following:

If you are designing a retention or detention pond, the smartest idea is to wait until after a downpour and see where most of the water has collected. Presumably, these water sodden parts will be at the lowest points of your turf, and where most of your run off and excess nutrients eventually end. Thus, this will be the best placement for your pond.

Of course, if the pond is going to be used for mainly decorative and aesthetic reasons, you will want to make sure that the pond is placed in a heavily trafficked and highly visible spot. While it may seem to add to the beauty and be tempting to surround the pond with many trees, this will only cause stress in the future. Falling leaves and animal waste will contribute to nutrient loading in your pond, which will add to the bottom layer sludge, developing a perfect habitat for bottom rooted algae... lots of it.

Another temptation and seemingly quick solution may be to build your pond over an unsightly and unwanted landfill. Do not be tricked into this enticement! In time, this will only cause you aggravation and considerable costs, as the area will most likely collapse and have to be refilled.

Finally, so you don't have to go through the extra hassle of installing one in the future, you should be sure that an electrical supply is nearby.

How will your pond be filled?

Is your pond going to be run-off dependant, or will it have a makeup water source such as a well or stream? There are benefits and drawbacks to both and the function of your pond will help you decide over one or the other options.

If it is to be run-off dependant, of course obtaining the water will hardly cost you anything. In the long run, though, excess nutrient build up is inevitable and this will negatively effect the appearance and quality of the water. You can be sure to expect excess algae and foul odors, unless you maintain the pond from the start. Also, because of droughts or floods, the water level will fluctuate. This will be detrimental to the shoreline where soil and plants will loosen, contributing to the sludge layer.

Filling in the pond with well water or from a stream, on the other hand, will allow you to maintain a constant water level and will prevent erosion. While it may be somewhat costly to fill the pond, in the long run it will be more efficient as it will be much more easily maintained.

Is the soil sufficient?

Once you have determined the general area of your future pond, you should test the soil to make sure it is low in nutrients so as to avoid algae overgrowth and other nutrient-overload related problems. You will also want to make sure the soil is not very porous. Otherwise, in time you will be left with nothing but an empty cavity.

Soil with a Permeability Index (PI) of 25-40 is the most desirable. If the soil falls below a PI of 20, you will most likely have to line or seal the pond.

Pond Liners

There are generally four types of pond liners:

Clay: A clay liner should be at least two feet thick and should be installed in 6-inch lifts then compacted. For every foot of water over ten feet, the thickness of the liner should be increased.

Bentonite: Bentonite is a premium core drilling mud and is considered a type of clay. When installing, it should be spread, disked rolled and compacted at 1 to 2 pounds per square foot. Upon drying, Bentonite is known to crack, which allows some water to seep. If your water source is run off dependant, water fluctuations are more likely to effect this cracking.

Flexible Liners: If clay or Bentonite is not available, an artificial plastic or rubber can be installed. While both are long lasting, in time the plastic will have to be replaced as it begins to deteriorate.

Concrete: This type of liner is the least expensive of all the methods. However, overtime it may form its own expansion joints (minor cracks,) which must be monitored for any ground sinking behind them.

*When using a pond liner, you should be sure to take groundwater into account and if present, should include a drain system that will allow water to flow laterally under the lining. This under drain will prevent the liner from floating due to ground water or gas build up.

What is the correct shape and depth?

The shape of your pond will directly influence the amount of maintenance needed in the long term. The ideal shape for a pond is circular (i.e. round, oval, oblong) as opposed to complex shapes (i.e. kidney, long and thin.) While unique pond shapes might be enticing, be forewarned that sooner or later you will have to face problems such as insect infestations and foul smelling and discolored waters due to poor circulation.

Depth is one of the critical factors which is often overlooked. If you create a pond that is too shallow, thermal stratification will occur during the warm months and without proper maintenance, you will be faced with high clean up costs. An ideal depth range is from at least 12 to 20 feet. Deeper depths provide lake bottoms with limited exposure to ultraviolet light from the sun which will deter excessive algae and nutrient overload. Water temperature in deeper depths also tends to be much cooler, allowing for a greater amount of oxygen, benefiting fish and overall water quality.

Slope

New research and water management practices have stated that by creating a gentle slope provides greater public safety and should be considered within every installation. This shallow shelf should extend out of the edge horizontally anywhere from 6 to ten feet and then drop off sharply at a minimum ratio of 3:1 to the maximum depth.

Slopes are also beneficial in the fact that they allow for the planting of certain species of aquatic plants that buffer nutrients as they run into the water.

Flora and Fauna

Drainage into your lake from fertilizers, grass clippings, and herbicides can cause many unpleasant water conditions.

Fortunately, there are also many types of aquatic weeds that can be planted around the perimeters of the pond to act as a barrier. Certain types of plants also float on the water. This blocks UV rays and direct sunlight, deterring thermal stratification and weed growth.

If you decide to have fish in your pond it will most likely be the Koi breed. These giant goldfish look-a-likes can be assets in ridding your pond of algae and consequently, insects.

What type of maintenance program?

Once your pond is installed, like the rest of your landscape, you will have to begin a maintenance program. While your first thoughts may turn to algaecides to keep the water algae-free, these are detrimental to the environment and can also create an excess of nutrients in the pond, resulting in repugnant smells and murky water.

A fabulous solution is installing an aerating fountain. Whether you choose a fountain that has an elegant, exciting spray pattern, or if you opt for a diffused aerator (which is virtually undetectable,) the benefits to your water quality are the same because both:

  • create a circulation pattern, discouraging thermal stratification
  • prevent fish kills caused by a shortage of dissolved oxygen
  • help aerobic bacteria breakdown nutrients
  • prevent sludge from settling at the bottom
  • break up stagnant waters where mosquitoes breed
  • keep water clear and clean

Surface spray aerators offer a spray pattern much like a water fountain, and are particularly popular among golf course owners, country club superintendents and private homeowner associations. While they are very cost effective, they raise property values and add to the impressiveness of your landscape. This effect can be expanded into the night with the addition of lights

Whichever type of aerator system you choose, you can be sure that you will be virtually doing no work. Basically taking care of themselves, aerating systems only need maintenance about every 3 to 5 years.

Remember Safety

As with any landscaping project, safety should always be a primary concern. Since installing a pond requires digging very deep, it is of the utmost importance that you have the area examined for utility lines. In many areas, professionals will mark your electrical, telephone, plumbing lines free of charge.

Careful planning is very much stressed because in time, without the proper preparing, the pond will need major restoration work which will be very expensive. However, with the correct design and implementation, your pond will be a sparkling accent to your property!

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Article Source: http://EzineArticles.com/6514465

Angela Hopko


Otterbine Barebo, Inc. has been setting industry standards in managing water quality in ponds and lakes for over 60 years by combining both function and beauty with their extensive line of surface aerators, subsurface aerators and giant fountains. To learn more about the benefits of aeration and the options available to you visit us online at http://www.otterbine.com/aeration_systems. Article Source: http://EzineArticles.com/6514465