Irrigation - how landscapers can maximise their water economy

With water bans set to rise, what can landscapers do to minimise the impact on their sector.

There’s a water shortage in the South East. And it won’t be the last. With the predictions that climate change will give us hotter, drier summers we might expect hosepipe bans to become increasingly frequent — and perhaps not just in the South East. The effects on landscapers and those installing irrigation into gardens could be serious.

Hosepipe bans can be an annoyance for the gardening public. For landscapers, however, they can be disastrous. When planting stock is on the nursery or in the landscaper’s holding area it can be watered using any of a range of irrigation methods. But transplant the trees and shrubs into a client’s garden and watering-in is reliant on buckets and watering cans. How can guarantees be given on the stock knowing that it can’t be properly watered? Some people will defer having their gardens landscaped, at least until next year.

The nature of landscaping means many firms work within a small geographical area of perhaps up to 30km travelling distance. Travelling out of the locality in order to beat the ban is out of the question for the majority and diversification is difficult — hard landscaping projects are usually accompanied by some planting. So what can be done?

It is worth checking out what type of ban is in place. There are actually two types of hosepipe ban that a water company can impose. If the company chooses to impose the "prohibition" type then all forms of watering with a hosepipe or similar equipment are prohibited. "Prohibition" is the most common type and covers all forms of irrigation using water from the mains supply.

The other type of ban is a "restriction" order.?In this situation it is up to the water company to define the equipment. With this type of ban it is worth checking the exact conditions since a "hose and sprinkler" ban may not cover drip irrigation systems. But a word of warning: you may well find yourself explaining the difference between the systems to the water company. The lack of recognition for the various types of irrigation available — and their different levels of efficiency — seems to be a major stumbling block.

"Technically you are not allowed to use an irrigation system when a ban is in place and everything should be watered with a watering can," states Access Irrigation managing director Matthew Pearce. For the landscaper this is impractical. But it is also inefficient in terms of water use, as Pearce explains:

"There are better ways of watering, more efficient ways of watering, but unfortunately the water companies do not seem to recognise the difference between a sprinkler and a drip system or that a drip system is more efficient than a watering can. We just have this blanket ban on both inefficient and efficient systems and rely on people not bothering to water at all. It’s a massive problem for landscapers."

The latest irrigation equipment includes some remarkably effective and efficient products. As a minimum, most systems now have a rain sensor so it turns watering off when it is raining. Controllers ensure that pop-up sprinklers are used at the most effective times but we are also starting to see technology that links requirement to supply by using probes in the soil to measure real-time moisture levels so the watering is in direct response to need. When the water companies estimate that hosepipe use can account for up to 70 per cent of demand on a hot summer evening, surely it makes sense to embrace such technology? Pearce believes so.

"Everyone can understand the need to conserve water but I do think the water companies have missed a trick here. Watering with a hosepipe is tremendously wasteful and we can sympathise with the companies wanting to ban this activity, but wouldn’t it be better to try and modify customers’ behaviour? I think water companies have missed an opportunity to educate the public on the best ways of watering," he says. "If they said they were banning hosepipes but allowing drip irrigation, then people would have installed drip systems. Gardeners would not go back to holding a hosepipe for hours in those years when shortages do not apply. The problem of high demand from hosepipes would be solved for good."

Landscape Watering Systems’ general manager Simon Edginton reports that installations of drip systems have been increasing in recent years, but not now. "When it comes to irrigation installation contracts, undoubtedly some landscapers will now be losing jobs or are finding jobs are postponed until next season. It’s understandable that private house owners question whether they should spend £5,000 on an irrigation system this year when they are unlikely to be able to use it," he says.

Garden designers are encouraged to use plants with lower water demands — the "Mediterranean stock and cacti" approach — yet the "English Garden" is recognised and envied the world round. Water harvesting (see below) is clearly a sensible approach. But changes in legislation hold the best answer. Current legislation is largely based on translations of previous by-laws from days when drip irrigation systems were rarely used and before the boom in the garden landscaping industry.

With the latest technology increasing the efficiency of irrigation, now is a good time for a campaign for the recognition of a tiered system of bans that reflect efficiency.

"What we need is sensible provisions for watering efficiently, especially for landscapers who at the moment are unable to water in newly planted gardens," says Pearce.

Hosepipe bans are primary legislation. That takes time to change. But Pearce believes the legislation as it stands is good enough for what is needed. "The Water Act of 1991 allows the water companies to ban or "restrict" the use of hosepipes for the watering of private gardens. At present there is a ban, but there is no reason why the water companies couldn’t change the ban to a restriction and allow for certain types of water efficient irrigation. In addition, the companies can apply for drought orders to restrict other non-essential uses such as washing patios," he says.

Landscaping is a multi-million-pound industry and provides the surrounds where we live, work and play. Water shortages may be putting them in jeopardy but modern irrigation systems, prudent design, correct installation and diligent maintenance can allow landscapes to grow.

Water collection and storage

Water butts have been popular with gardeners for years and represent one of the simplest forms of harvesting, or collecting, rainwater. A drip system designed to work from gravity supplies can be connected to water small gardens.

Access Irrigation has introduced an above-ground water storage tank, with filter and collector, to take advantage of rain falling on roofs.

"A house roof provides a large catchment area and, despite lower rainfalls, a surprising amount of water falls from the sky," says Pearce. London has an average rainfall, even in summer, of over 50mm per month. Pearce calculates this yields around 50 litres of water for every 1sq m of roof catchment. "Half an average detached-house roof could therefore yield around 2,500 litres of water per month," he says.

Holding 650 litres of water, the tank has a capacity four times that of a standard water butt. The 68mm to 100mm high-capacity down-pipe connector filters the water before it enters the tank, reducing the risk of disease contamination.

From the water tank, a pump can be used to pressurise the water supply to run drip irrigation on the borders and tubs.
The tank costs £322 ex VAT delivered — the filter and collector unit are £49 ex VAT. Two tanks, giving 1,300-litre capacity, plus a link pipe, filter and collector are available at the special price of £679 ex VAT delivered.

New products for golf and sports turf

Aimed at golf courses is the new 810G Series tee sprinkler from Toro Irrigation. Distributed in the UK by Lely of St Neots in Cambridgeshire, the sprinkler, like its 835 and 855 stablemates, offers both full- and part-circle operation, and has an arc setting that can be adjusted from 30° to 330° in part-circle mode and to unit-directional in full-circle operation. A pop-up height of 127mm means the spray should clear taller grasses. The sprinkler is said to be ideal for block system applications requiring spacing of nine metres to 21m.

For sports field applications, Toro’s TR50, TR50XT and TR70XT contain many features of the 810G, including full- and part-circle capability and TruJectory technology. The two XT models boast Toro’s X-Flow shut-off feature to enable users to carry out dry-nozzle changes. In addition the company is introducing a range of RainSensors for use with existing Toro control systems in both golf and sports field applications. The three new models include a hard-wired version, a wireless unit with digital display and a wireless model with a rain/freeze sensor and digital display.

Water efficiency tips

1.    Appraise the site to determine requirements and opportunities for water harvesting.
2.    Use modern irrigation equipment. We can do more with less by scheduling watering at the best times and linking systems to weather stations and a soil moisture monitor.
3.    Good system design gives efficient and uniform distribution of water.
4.    Correct installation and management with regular checks and servicing to ensure optimum performance.
5.    Use water-retaining polymers or supplements and mulches.

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