Water Garden Construction

By: CERTIFIED AQUASCAPE CONTRACTORS  


Water Garden Construction Techniques

What is a Water Garden? And why do we have a separate section for Pond Construction and Water Garden Construction? The reason is, that when people are referring to water gardens, they mean the whole thing. Water garden construction is about the big picture; it's about putting the whole scene together so that when a person is in the water garden's presence, they feel like they're in a completely different environment.

What's the attraction? Water gardens capture the imagination of all who witness their beauty. Many people go on long, exhausting treks into the wilderness just to see a section of a river, a waterfall, or a stream. They're beautiful and inspiring, but why seek them out? Maybe it's the feeling of being one with nature, or the contemplative feeling of peace we find within ourselves.

The bottom line is, whether natural or man-made, waterfalls and streams are an amazing part of the world we live in. They deliver and clean the water that's so vital to our existence. It's an honor and a gift to be able to design and construct them, and we owe it to ourselves as pond builders, to master and hone water garden construction techniques to their perfection.

Waterfall and Stream Construction Basics

A man-made waterfall is simply water pumped from one body of water to an area above that body of water. Then the water falls back down due to gravity. If you do it right, it will look good, sound good, and not lose any water in between. Before you get started, there are a few questions you'll need to answer.

How far and how high will the water need to be pumped?

How wide will the waterfall be?

What type of rock is being used?

What is the desired style of the waterfalls?

To achieve the desired effect, we first need to know how high and far the water is being moved. This information determines which pump will be required to complete the task. Be sure to do your homework on the technical side, and when in doubt, use Aquascape's technical service dept. to help you eliminate any mistakes.

Be sure to read our section on pond construction for tips on building your pond.

Once the pond is built, we're ready to start on the stream and waterfall construction. We have the list of components, we know the rock that we're using and the style of the falls, and we know where it's starting and ending. How do we connect them in an interesting yet functional manner? The easiest way is to follow Mother Nature's designs.

As you design, layout, and construct the stream portion of the project, there are a few tips you should keep in mind to help you create the most naturalistic stream possible. Remember, water wants to run downhill as quickly as possible, and along the way it hits objects that are harder than the surrounding soil (large rocks and logs), and encounters sharp elevation changes. When this happens, the water moves off course, and the new watercourse continues downhill until it hits another object, and the cycle starts all over again. The larger the hill, the greater the odds of the water hitting objects. The goal is to copy this look as much as possible. With that in mind, let's start constructing the stream.

Stream Construction Techniques

When excavating a streambed into an existing slope or hill, simply mark the stream edge, and dig down about 6" to 8" deep. This allows enough room to accommodate the rock, gravel, and water with a couple of inches to spare. Those couple of square inches will allow for some settling and compaction of the soil to keep the stream leak-free. You can dig the stream deeper, of course. We've given the minimum amount of space needed.

The stream should twist and turn as it makes its way towards the pond. The turns will increase the sounds. and will also increase the number of viewing areas in the water garden. The more places it can be seen, the more the water garden will be enjoyed.

Getting Creative with the Stream

The stream should get narrow in areas, and then widen out and slow down in others. Make sure you use a good mix of stone and gravel to create a natural look. Fill the streambed with aquatic plants and you've just created an awesome supplement to your filtration system.

The hardest part about streams is learning how the water reacts in certain situations. When a stream is long and without much slope, the water will tend to move too slowly, causing water to well up along the sides. This can become a problem if the edges aren't high enough.

Although there are no concrete rules (they vary from project to project), we follow a simple set of guidelines based on experience and common sense.

  • Always slope the streambed towards the pond.
  • Have areas within the stream where the water can pool.
  • If the stream narrows in one place, open it back up downstream.
  • Leave several inches of soil and liner above the proposed water level in the stream.
  • The water depth of the stream is determined by the height of the weir in the closest downstream waterfall.
  • High water flow rates need a wider stream and / or higher edges.

The Waterfalls in the Stream

Each waterfall area is dug out according to the size of the rock(s) being used. When possible, we prefer to use one rock for each waterfall in the stream and rapids areas.

  • The easiest waterfall style is the sheet of water effect.
  • Place two large boulders on either side of a level waterfall weir.
  • Fill between the boulders with smaller stones, and place a piece of flagstone on top.
  • Adjust the flagstone for the best fit, then check it with a level.
  • Remove the flagstone, and put a layer of foam on the liner.
  • Reset the flagstone and you're done.

Rapids or falls made up of small boulders are also fairly easy to build because they're typically small.

  • Set the main boulders that will frame the rapids area.
  • Dry set a series of smaller stones between the main boulders, they should fit tightly together.
  • Choke the water down with strategically placed stones, so it's flowing at twice the normal rate. The typical flow rate is 1500 gph for every foot of waterfall width. Twice the rate would then be 3000 gallons for every foot. Rapids are typically 1' to 1 1/2' wide, which would require 3000 to 4500 gph.
  • This high flow rate is necessary to create the desired white water within the rapids. The best way to see the water is when it's flowing over smooth stones. If you don't have the higher flow rate, the water will still flow over the stones, but it will hug the rocks and only make them appear wet. The smooth rounded stones demand a larger volume and greater water velocity. Otherwise, you won't have the look and sound of white water, and the falls could look somewhat anemic.
  • Remove the smaller stones, lean the main boulders forward, and foam behind them. Set the next course of small stones in place, and apply more foam.
  • Continue placing small stones on top of each other in an overlapping fashion, covering the joints of the stones underneath.
  • Work your way all the way up to a level a couple of inches higher than the waterfall weir. This will hold the gravel in the streambed in place so it doesn't get washed over the falls.

Creating a Spring

Next we'll use BIOFALLS to create a spring. The hardest part of using BIOFALLS like this, is getting the level of the water set properly. The water level in the BIOFALLS spring should be set so it's 1" to 2" higher than the water level of the pool that it flows into.

Whatever you do, don't set the BIOFALLS below the upper pool. If it's too low, it'll have to be moved to keep it from leaking, and that's no easy task.

Treat the stonework just like the rapids discussed above. The water will well up within the BIOFALLS and flow down between the boulders. The nice thing about this is that since you don't have a bermed up area that sticks out, everything is at grade level, and it truly looks like a spring.

Stream Construction

Streams set the mood in a water feature. When you close your eyes and envision a stream in your mind, what image appears? Is it a loud crashing watercourse showing you the power of water, or is it a slow meandering stream, making you fell peaceful and tranquil? You may have the most beautiful visions, but without an understanding of stream construction, it can become a flash flood of problems.

We love to design and build streams, which we feel are an integral part of a water feature's form and function.

Before you start designing your water garden, you should know what your capabilities are. All it takes to build an impressive stream is a little extra liner, rock, gravel, and pipe. Well, it's not quite that easy. There are a few other things you must know before getting started.

  1. How high and far does the water have to go?
    Sure, it's great to have a stream tumbling out of the mountains, but remember, you have to pump the water up there first. The greater combined height and distance equates to a greater amount of head pressure put on your pump. You may have to compensate for this by using a larger pump and increasing your pipe diameter to allow for a higher flow volume. This will change your costs somewhat, and we  would definitely recommend going with a high efficiency pump to help offset some of the electrical costs. Another option is to use multiple pumps and piping to supply a greater water volume. We prefer this second option whenever possible because it provides greater flexibility. You can shut one pump down without stopping the entire stream.
  2. Increase your reservoir.
    One of the most frequent design flaw is having a large upper pond or stream going into a small lower pond. It should be the exact opposite; the lower pond should always be larger. The reasoning behind it is simple. You need a large volume of water where your pump is to supply the water in your stream. This becomes crucial during times of pump maintenance or power outages.
  3. An often overlooked part of stream construction is the thickness of your waterfall stones.
    Water will eventually seep through the foam joints if the pumps are off for prolonged periods of time. The water will slowly seep around thick stone, resulting in water loss equal to the thickness of that stone.
  4. Three basic scenarios that you will encounter.
    a. A flat backyard
    b. Slope going away from home
    c. Slope going towards the home
  5. A Flat Backyard
    This is easy to work with. You may need to bring in fill material if you want a fast moving stream. Otherwise, do a combination of deep stream with fast upper stream.
  6. Slope Going Away from Home
    This is more challenging and more expensive. You will definitely have to bring fill material to the site if you want a stream visible from the main viewing area. You must be very careful about fill compaction and retaining wall integrity. If done properly, it is an amazing transformation, and well worth the challenge.
  7. Slope Going Towards Home
    This is the easiest and most natural looking. Simply shape and carve the hillside for the desired effect. The trick with this is to try to keep all soil on the site. You may have to haul some away, but it will not be a problem as long as you make provisions ahead of time.
  8. The Deep Stream
    If you are set against the concept of a large lower pond, simply incorporate the stream into the pond. No matter what, never make a small lower pond with a large stream. Even though you may have a great vision in your mind's eye, you could be creating a major problem by not adhering to these few simple rules on stream construction.

One more thing before you get started...
You may be anxious to get out and start building a dreamscape with lots of flowing water and a serene pond filled with lilies and extraordinary Koi. Before you get your marking paint and shovels out, there's one more greatly misunderstood concept of water garden construction to talk about here.

It seems that many people are so enthralled with the sound of water, that all they want is a huge waterfall and stream that fills their property with the incredible sound of falling water. The only problem is, if the pond gets neglected, and / or forgotten about, it doesn't work very well.

Let your creativity take over and see what happens. Regardless of the outcome, you'll definitely learn something and, in the process, you'll learn a little each time. The bottom line on water garden construction is, if you enjoy yourself, it will show in your craftsmanship. There's no greater feeling than the satisfaction of a job executed to perfection, and loving every minute of it.

See our page on Water Garden Plants for more water garden construction tips.

Certified Aquascape Contractors (CAC's) are the most qualified and informed  installers in the pond construction  industry. All CAC's are required to attend continual training and education seminars and maintain a proven record of outstanding work and dedicated customer service and support.

To Find a CAC in your area Click Here

The content of the Pond & Water Garden Resources Website comes from the book Pond Builders Bible everything Aquascape Designs Does Revealed. Published by Aquascape Designs, Inc. / The Pond Guy Publications. | Batavia, IL


 


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