PRODUCT FEATURE
Do the maths first with Graf UK
After the record-breaking wet winter of 2019/2020, it is unlikely that actually harvesting rainwater is front of mind with the British people. But with volatile climates increasingly the norm, it is becoming even more important to consider rainwater harvesting as a vital addition to a property’s estate. The average house roof in the UK collects enough rainwater in a year to fill about 450 water butts so collecting water in rainstorms to irrigate in dry periods should be a no-brainer. Setting up a rainwater irrigation system for a small property is relatively simple – a couple of tanks under downspouts is well within the capability of most DIY-ers. But they will only irrigate one to two flower beds. Anything more than that, involving overground water tanks holding up to 500 litres and underground water tanks holding up to 52,000 litres, requires the help of professionals. But first, how much water will there be available for irrigation? To determine the tank size based on yield, the following parameters should be considered: • Catchment area (m2) • Pitch/texture of roof - catchment coefficient (%) • Annual rainfall figure (mm) - this can be found on the Met Office’s climate page • Filter efficiency To determine demand, the average north European garden requires between 60-200l/m2 x area in m2 x 365 days. Once an annual figure for both yield and demand has been determined, multiply the figures by 0.05 to get a 2-3 week storage volume. Then it is the smaller of the two tank sizes which is usually implemented. So it makes sense to focus first on how much can actually be collected from a roof, rather than how much is needed. For more details visit www.grafuk.co.uk or call 01608 661500
Water Aid Garden irrigation for over 30 years
Waterwell has been at the forefront of garden irrigation design, installation and maintenance in London for the past 30 years. The team work in commercial and residential settings, ranging from hotels and London squares to private gardens, roof terraces and small patios. In addition the compant has been involved in the construction of award-winning gardens at RHS Chelsea and Hampton Court flower shows. In a fast-changing world, at a time when climate change is presenting new challenges, Waterwell is committed to using the latest irrigation technologies and practices to deliver water as efficiently and effectively in every garden situation. As part of this process, the company installs wi-fi controllers, which can be monitored and adjusted remotely and are connected to virtual weather stations so that watering regimes respond automatically to current conditions. Its maintenance service is an important part of the business. With an experienced team servicing hundreds of systems on a contractual or call out basis, we ensure that gardens are irrigated at their optimum level all year round. www.waterwell.co.uk info@waterwell.co.u 0208 742 8855
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