Landscape Architect Articles

Fueling Water Features With Rain05-27-09 | News

Fueling Water Features With Rain

By Matthew Doyle, Assistant Editor

This may seem like a relatively straightforward water feature. However, connecting it to seven rainwater storage tanks, an irrigation system and LED lighting while working around eight other trades doing a full home remodel on a slope full of rusty car parts complicated the picture substantially. Daniel Wilson and crew at Wilson Environmental Design, however, were up to the challenge. All Images Courtesy of Wilson Environmental Landscape Design.

Water conservation is an ever-growing concern that has brought water features under fire by some as a decadent misuse of an increasingly precious resource ?EUR??,,????'?????<

Wilson has a substantial educational background, with an undergraduate degree in Biological Science in 1994 and a Professional Masters in Environmental Science and Management in 1998, both from the University of California Santa Barbara. He is also a National Ready Mixed Concrete Association (NRMCA) Pervious Concrete Installer and California Landscape Contractor Association (CLCA) Provisionally Certified Water Manager with 10 years in the industry. His company specializes in what he terms environmentally responsible projects.

Design to Installation: Guiding Goals

A recent water feature project required much of that educational background with a healthy dose of ingenuity. A client desired a beautiful backyard water feature that his two actively growing children could enjoy that was also ecologically friendly.

The result required 20 tons of sandstone boulders, all locally obtained to minimize energy use in shipping per the client?EUR??,,????'?????<

The lower pond (4 feet by 6 feet) was installed roughly halfway through the installation sequence. Flagstone steps featuring a sitting nook went in right before the lower pond assembly.

A selectable pump and an underground cistern, capable of holding the entire upper streams water supply were installed so the upper stream can be run independently from the ponds. The poor-performance of a previous installation made serviceability a priority for Wilson, resulting in a check valve, union and direct burial junction box with pump plug being added to the unit.

At this point, the upper pond (5 feet by 7 feet) is being laid out with the beginning of the upper stream visible. To meet the sustainability requirements desired by the client, the sandstone in both ponds was obtained within a 20-mile radius. Recycling the rubble from a demolished retaining wall served the same purpose.

The 15-foot stream between the ponds went in after the upper pond layout and installation, with an EPDM liner providing water integrity. However, it was discovered during excavation that a previous owner had used the yard as a car dumping ground. As a result, jagged and rusting parts and glass had to be carefully removed so as not to compromise the liner.

Benefits

Taking such an approach proved to be beneficial to Wilson in several respects. Primarily, client desires were meet. In addition, with adequate rainfall, the installer/designer estimates the homeowner?EUR??,,????'?????<

Challenges/Solutions

Getting the water feature, rainwater harvesting system, irrigation and LED systems to interact properly was enough of a challenge in itself. However, several other factors complicated things further.

Slope

According to Wilson, the gradient involved was the biggest site challenge. It essentially turned a water feature project into a slope retention effort as well. However, he simply saw this as an opportunity and utilized what he termed ?EUR??,,????'?????<

Aikido is a martial art that utilizes an opponents attacking momentum to ones own advantage. In a similar manner, the contractor here used the slope retention challenge meet in installation as an opportunity to recommend a flagstone stairway and sitting nook. The homeowner found the idea of enjoying cocktails from the feature at sunset appealing and was immediately sold.

Number of Systems

Wilson also identified the number of systems and the tight space in which to put them as a major challenge. He roughly estimates in a 3,000 square foot backyard, his team had 1,200 square feet to install roughly 550 linear feet of drain pipe (including gravity drain rainwater distribution), subsurface irrigation stup-ups, the pond auto-fill and low voltage wire to feed the LED lighting. This all also had to be done with an eye toward avoiding chopping infrastructure while installing future plantings.

Flexibility was a major part of the solution according to the design/installer. For instance, he wanted to minimize the use of poly vinyl chloride (PVC), as he claims the plastic is more detrimental to those who produce it and the environment as a whole compared to polyethylene (poly). However, three connections required specialty fittings only available in PVC from Australian companies.

Obviously, there are major problems trying to bond PVC to Poly with glues meant for either, so an alternative connection method had to be devised. Wilson coated the appropriate inside and outside diameters of both components with clear silicon, before drilling pilot holes. He then locked the pieces in place with stainless steel screws.

The 35-foot upper stream and waterfall followed the section between ponds. A continuous pump maintaining circulation between the ponds was installed before the rainwater harvesting system was placed. To finish off the installation, plumbing to auto-fill the water feature was run and LED path lights made operational.

Other Trades

Another challenging aspect of the project according to the landscape contractor was the number of other trades present. The house was undergoing a full remodel throughout with eight other trades at work. The result was congested working space and a need to coordinate with other schedules to minimize the trades holding one another up.

Wilson?EUR??,,????'?????<

Car Parts

An unpleasant surprise was the discovery that the water feature excavation area had been used as a car part dumping ground by a previous owner some 30 years ago. As a result, the subgrade was full of rusted, sharp car parts and shards of glass. The result was a need for a particularly cautious and thorough excavation to protect against injury and water feature leaks. The parts were also recycled in compliance with the environmentally friendly goals of the project and Wilson?EUR??,,????'?????<

The rainwater harvesting system features 6,000 gallons of storage, with rainwater going from the roof through gutters to a leaf screen, past a .9-millimeter mosquito screen, into a first-flush tank before entering the storage tanks. The storage tanks either feed fruit tree irrigation or a lower pond auto-fill, with the water either going from the lower to upper pond and/or upper stream, depending which pump is on.

Business Expansion Potential

Wilson?EUR??,,????'?????<

Interested in replicating his success? When asked how the landscape contractor can evaluate the environmental impact of materials and methods, a key aspect in what Wilson does, he responded there are two major considerations. First, the landscape contractor claims ?EUR??,,????'?????<

The basic idea is to use materials and methods that require the least amount of energy to create a product or assembly that will last as long as possible. However, it?EUR??,,????'?????<

Wilson identified the International Organization for Standardization?EUR??,,????'?????<

More information can be found at www.iso.org/iso/iso_catalogue/management_standards/iso_9000_iso_14000/iso_14000_essentials.htm.