Water Wall Units Explained

Author: Danielle Dickinson

Article: Water walls are almost a must in today’s contemporary style gardens. Often the focal point of the garden, this is due not only to their grandeur but also to their tactility. Modern day urban noise such as traffic can be drowned out by such a feature creating a calming environment favourable to sipping a glass of wine and enjoying relaxed conversation. Necessary to create these impressive walls is a prefabricated unit called a Water Wall Trough or Sheet Descent Unit. These units are specifically designed to produce an even flow of water along the entire length of the unit. There are two main types of Water Wall Troughs. Made from Stainless Steel, Copper or PVC, each type distributes the water in a different way. Below we explain the differences between the two main types of Water Wall Troughs available.

Sheet Descent Water Wall Unit Water Distribution Effect

Pictured above, this unit distributes the water from the trough over the spout or lip and down the surface of the wall into a catchment reservoir or pond (can also be used as a ‘free-fall’ unit). This unit brings subtle noise and movement into the garden. Wonderfully tactile, it invites the onlooker to touch the wall and feel the cool water running through the hand. The shimmering effect of the water can be captured at night with the inclusion of subtle lighting.

Installation

This unit should not be installed any higher than 2.0m above the surface of the water in the catchment reservoir. If used as a ‘free-fall’ unit this height reduces to 0.8m. Flow Requirement This unit requires approximately 4500 litres per hour per metre width. This should produce a film of water approximately 3mm thick. Some adjustment in flow is achievable with the use of an inline value. See examples 1 & 2 for further explanation.

Catchment Reservoir

Waterfall catchment troughs are designed to be positioned at the base of a sheet descent water wall where the wall surface is fairly even ie. tiles, render, smooth stone, metal, glass etc. They are large enough to suit most submersible pumps. Where a surface is irregular and likely to cause splash such as with pebbles, rock etc a larger catchment reservoir should be used to stop the water from splashing out of the feature. Not only is this a waste of water in times of drought but it is truly amazing how quickly a water feature can empty when splash becomes a problem. Rectangular Statue ponds are recommended in these circumstances.

Pump

The pump required is governed by the flow requirement and head height (ie. the height at which the waterfall is installed above the surface of the water in the catchment reservoir). Example 1:- Installing a 1.0m Sheet Descent at a head height of 2.0m

This unit has a flow requirement of 4500 litres per hour (4500 (litres) x 1 (metre)) therefore requires a pump that will supply 4500 lph at 2.0m high. Check pump performance charts to find a pump that will supply this flow at the required height. In this example a Blagdon Amphibious 8000 will push 4980 lph at 2.0m high and is therefore suitable. Example 2:- Installing a 0.8m Sheet Descent at a head height of 1.5m

This unit has a flow requirement of 3600 litres per hour (4500 (litres) x 0.8 (metres)) therefore requires a pump that will supply 3600 litres at 1.5m high. Check pump performance charts to find a pump that will supply this flow at the required height. In this example a Seerose UP90 Fountain Pump will push 3840 lph at 1.5m high and is therefore suitable. Projecting Water Wall Unit Water Distribution Effect

This unit projects the water out from the wall in a clear and even arc, re-entering the water approximately 200mm away from the wall providing a dramatic, lively effect. This involves the senses and proves difficult for even the most staid personality to resist the urge to reach out and play with the curtain of water produced by this unit. Further enrichment is accomplished with the use of lighting at night. A simple submersible spotlight positioned under the curtain of water is all that is required.

Installation

This unit should not be installed any higher than 1.2m above the surface of the water in the catchment reservoir. The water will begin to break up if installed any higher. A high-flow projecting waterfall is available which may be installed up to 2.0m high (please enquire).

Flow Requirement

This unit requires approximately 7200 litres per hour per metre width. This should produce a film of water approximately 5mm thick. Some adjustment in flow is achievable with the use of an inline value. See examples 1 & 2 for further explanation.

Catchment Reservoir

Rectangular Statue ponds are recommended for use with a Projecting Water Wall as the catchment reservoir needs to protrude at least 500mm from the wall to avoid losing too much water from splash.

Pump

The pump required is governed by the flow requirement and head height (ie. ie. the height at which the waterfall is installed above the surface of the water in the catchment reservoir).

Example 1:- Installing a 1.0m Projecting Water Wall at a head height of 1.0m

This unit has a flow requirement of 7200 litres per hour (7200 (litres) x 1 (metre)) therefore requires a pump that will supply 7200 lph at 1.0m high. Check pump performance charts to find a pump that will supply this flow at the required height. In this example a Seerose UP150 will push 7740 lph at 1.0m high and is therefore suitable. Example 2:- Installing a 0.8m Projecting Water Wall at a head height of 0.5m

This unit has a flow requirement of 5760 litres per hour (7200 (litres) x 0.8 (metres)) therefore requires a pump that will supply 5760 litres at 0.5m high. Check pump performance charts to find a pump that will supply this flow at the required height. In this example a Seerose UP120 Fountain Pump will push 6840 lph at 0.5m high and is therefore suitable. TIP It is always better to ‘oversize’ the pump rather than to purchase a pump that will only just suit. Allowances need to be made for loss of flow through tubing and fittings. It is far more practical to buy a pump larger than required and restrict the output buy a valve, as it is impossible to get more performance than the maximum specified on any particular pump.

About the author: Danielle Dickinson is an avid water feature enthusiast. She is a regular contributor to Gardening Magazines. Visit her website <a href>http://www.waterfeaturesonline.com.au for more information on building and maintaining any type of Water Feature as well as a huge range of water gardening products.