Streams add to the sights and sounds of a pond and serve as biological filters for a pond. While more complex to design, they are well worth the time.

Stream Construction Before building a stream take a walk in nature and see how they run. Do they meander and wander? Do they gurgle and babble or are they tranquil and smooth? Does the flow bounce from one side of the stream to the other? Whether your stream bubbles and churns or not is dictated by the elevation change. You need to have at least a 1 inch rise for every foot of length if you want more than a canal. The more the rise, the more the babbling and churning it will do. You do not have to live on a hill to make a babbling brook. A flat yard can have a bubbling brook as well. Remember, a 12 foot stream only needs a 1 foot rise to to make noise. Of course the more rise, the more you can do to add character to the water flow.

The stream channel is much like building a pond except it is only inches deep and longer. It will require a liner (preferably EPDM) that totally contains the water. The width of the water channel in the stream should be no narrower than 8 inches after the rocks are added. Do not forget to add width and depth for the rocks you will be using for the sides and bottom. Add an extra 4-6 inches on each side of the stream for height adjusting the wall height and to compensate when the soil settles around stream.

Fold it down, creating a double wall. You can then pull it up as needed. The amount of water the pump should produce should be from 200 to 400 gallons/average inch of width. So, an 8 inch stream should have between 1,800 to 2,400 gallons/hour running through it to look its best. Nothing adds more character to a stream than bends and turns as they look very natural (especially when compared to streams that run in a straight line). Once you have laid the rocks that will form the sides, fill in the cracks and holes with expanding foam (also known as Great Stuff in a red and yellow can). You can get it at any hardware store.

Allow it to dry for at least 4 hours and break away the excess. This stuff will expand to more than 3 times its original size so allow for that or you will waste a lot and have more work to do to remove the excess. Once the rocks are sealed in place, it is time to turn on the stream and start placing the large rocks on the bottom. Start at the end of the stream and work your way back or you will be adjusting rocks twice. Make the water run at 90° to the length of the stream to create a more brook-like appearance.

Allow the stream to widen for a short length then narrow it and the water will speed up in the narrow sections. Once you like the general appearance of the stream, turn the water flow off, let the stream bed dry out and add expanding foam to the holes under the larger rocks. This will force more water to go over rather than under them. To give the stream more sound, make steps of rock 6 inches up from the bottom of the stream, make sure to allow for the sides of the stream to contain the water. Run the steps at different angles to the length of the stream. Fill the under sides with expanding foam to prevent water from going under the step. Add a rock about 3-4 inches away from the step and it will make the stream gurgle and bubble.

Add a thin layer of 1-2 inch diameter river rock to the bottom of the stream. Don't worry if there is a little liner showing. It will add the appearance of depth to the stream and will ultimately be covered with algae and silt over time. The exposed expanding foam will be covered with algae and silt in about 4 weeks so don't work too hard at hiding it. Now comes the easy part; turning the water on and making the final adjustments. Then, sit back and enjoy your work.

See also:
Streams and "Neat Stuff"