Post by RRusso on Feb 15, 2005 4:25:12 GMT -5
Waterfalls provide aesthetic and functional elements to a waterscape: sights, sounds, aeration, oxidation of wastes, dissipation of chlorine are the most noted benefits.
Design:
There are as many different designs as there are waterfalls themselves. As we have mentioned in previous articles on design, consideration must be given for the effects of splash and wind to keep the water in your system. The provision of drops and pools in a fall design versus semi-smooth hissing, gurgling streams is more a matter of taste than function. It is suggested you visit and sketch as many operational falls as practical to gain an understanding of your design.
What is the intent of the falls? To whisper, cover street noise, impress...? Here a high plunging effect does all three and much more. This twenty some foot height is also effective in attracting the public from a large open space in front of the walkway. LA Arboretum.
Construction:
The actual construction of waterfalls ranges from potentially a simple, straightforward matter to a totally-frustrating, leaky, massive nightmare.
Thankfully there exists appropriate, simple technology for easily building any size and shape fall. This article details the necessary elements, materials, tools and steps to completion for constructing waterfalls.
The_Trick:
The single most important item in the construction of a waterfall is the use of a PVC or polybutyl liner placed over a structural "trough" in such a way that any water that is pumped into the falls ends up in the system.
In_The_Beginning:
When you can use a single piece of liner for both the basin(s), stream(s) if any, and falls, do so. If not practical or possible, as in where a fall is being built on an existing water effect, a piece of liner can be fit to overlap the extant berm (edge).
Foundation:
After conceiving and making a sketch of everyone's idea of the finished product, comes consideration of the foundation the fall is to built on if outside the basin. Your fall must be built on a solid, compacted surface, or else the mass of the fall settling may cause structural failure. The base and trough of the fall must rest on an immovable base. If necessary, dig a form in or above the ground, place gravel and sand, reinforcing mesh, liner ,rebar and pour a concrete foundation. Upon this base you'll form a trough, the actual water-conveying, waterfall stream-bed. This does not have to be aesthetically pleasing at this point; only functionally able to accommodate the flow of water desired. Fall foundation form at right.
Rockwork, wood, plants, ornaments are mortared or otherwise affixed onto and into this trough structure. The actual discharge/s near the top of the falls can be fitted over or laid in the foundation. It can be seen that if objects in the trough lose water, there will be no loss as it will still be within the system due to the integrity of the liner.
Another pertinent article in this series that may aid in the Design and construction of water falls is: ,Concrete in Construction of Water Features.
It is advised that waterfalls be constructed with the basin/s they are emptying into being drained and that the concrete, mortar, grouts possibly being used be treated/cured with an acid bath prior to going on-line.
Done right, you don't see plumbing, electrical, any equipment.
Plumbing:
One last note: If you haven't provided for an alternate discharge and drain for your pond, this is your big chance. The discharge line can be fitted with a three way valve or two one-way ball valves and a tee to facilitate partial water change, diversion of water from the falls.
Design:
There are as many different designs as there are waterfalls themselves. As we have mentioned in previous articles on design, consideration must be given for the effects of splash and wind to keep the water in your system. The provision of drops and pools in a fall design versus semi-smooth hissing, gurgling streams is more a matter of taste than function. It is suggested you visit and sketch as many operational falls as practical to gain an understanding of your design.
What is the intent of the falls? To whisper, cover street noise, impress...? Here a high plunging effect does all three and much more. This twenty some foot height is also effective in attracting the public from a large open space in front of the walkway. LA Arboretum.
Construction:
The actual construction of waterfalls ranges from potentially a simple, straightforward matter to a totally-frustrating, leaky, massive nightmare.
Thankfully there exists appropriate, simple technology for easily building any size and shape fall. This article details the necessary elements, materials, tools and steps to completion for constructing waterfalls.
The_Trick:
The single most important item in the construction of a waterfall is the use of a PVC or polybutyl liner placed over a structural "trough" in such a way that any water that is pumped into the falls ends up in the system.
In_The_Beginning:
When you can use a single piece of liner for both the basin(s), stream(s) if any, and falls, do so. If not practical or possible, as in where a fall is being built on an existing water effect, a piece of liner can be fit to overlap the extant berm (edge).
Foundation:
After conceiving and making a sketch of everyone's idea of the finished product, comes consideration of the foundation the fall is to built on if outside the basin. Your fall must be built on a solid, compacted surface, or else the mass of the fall settling may cause structural failure. The base and trough of the fall must rest on an immovable base. If necessary, dig a form in or above the ground, place gravel and sand, reinforcing mesh, liner ,rebar and pour a concrete foundation. Upon this base you'll form a trough, the actual water-conveying, waterfall stream-bed. This does not have to be aesthetically pleasing at this point; only functionally able to accommodate the flow of water desired. Fall foundation form at right.
Rockwork, wood, plants, ornaments are mortared or otherwise affixed onto and into this trough structure. The actual discharge/s near the top of the falls can be fitted over or laid in the foundation. It can be seen that if objects in the trough lose water, there will be no loss as it will still be within the system due to the integrity of the liner.
Another pertinent article in this series that may aid in the Design and construction of water falls is: ,Concrete in Construction of Water Features.
It is advised that waterfalls be constructed with the basin/s they are emptying into being drained and that the concrete, mortar, grouts possibly being used be treated/cured with an acid bath prior to going on-line.
Done right, you don't see plumbing, electrical, any equipment.
Plumbing:
One last note: If you haven't provided for an alternate discharge and drain for your pond, this is your big chance. The discharge line can be fitted with a three way valve or two one-way ball valves and a tee to facilitate partial water change, diversion of water from the falls.
