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1 Information from Welcome to our Rainwater Harvesting shop on the web. People all over Britain are realising the need to save rainwater for later use both outside and inside their homes. Our online shop is serving both consumers and professionals who want bigger tanks at lower prices. In this information pack you will find: * How to use Rainwater, including your options for installing a system * Why we must use rainwater * Frequently Asked questions 1

2 Welcome To Our Rainwater Harvesting Shop We want you to benefit from your own rainwater coming off your own roof. Doing this you will conserve and make better use of the world s most precious resource. You don t need drinking quality water bought in from miles away to clean your car, wash the patio or fill a pond. You don t need drinking water to flush WCs or in the washing machine. And your garden much prefers chemical-free rainwater. In fact, use rainwater whenever you don t need drinking-quality water. Use Rainwater in the Home Most of us have been using small water butts in the garden for years. But now the interest is to use rainwater in the home. After all, 93% of normal mains water use is in the home, and 30 to 40% of this literally goes down the toilet. Installing a domestic system is more straightforward in a new-build or during a renovation project, but with some alterations to interior plumbing, a system can be added to an existing house. Use Rainwater outside Although only 7% of mains water is normally used outdoors, this rises to 70% during a drought, and this is when a hosepipe ban could come into force, just when the garden most needs the water. The dry summer of 2006 saw hosepipe pipe bans on watering gardens and cleaning cars. New legislation will give water boards the right to prohibit using hosepipes for other outdoor cleaning purposes such as washing boats, patios, drives and windows, and also for filling swimming pools, ornamental ponds and hot tubs. This gives an additional incentive to have a large capacity rainwater harvesting system to cater for various outdoor activities. The Pressure is on to use rainwater instead of mains water Lots of us have for years seen the logic of using rainwater instead of rainwater for 50% of our daily water needs. Now we have official encouragement. The new Code for Sustainable Homes which came into force in May 2008 makes rainwater harvesting obligatory for social housing and highly desirable for the private sector. Planning applications with sustainable options such as rainwater use are favoured and planning regs regarding hard standings have changed to encourage collecting rainwater to offset flood threats. Businesses (but sadly not householders yet) have tax incentives to install rainwater systems. An efficient use of rainwater adds value to your home or business both environmentally and financially. Rainwater harvesting can reduce flood threats During the summer of 2006, we were desperate for water, but the summers of 2007 and 2008 have created considerable flood damage. Rainwater collection is seen as one way of alleviating flood threats. We have seen an increasing number of planning applications where some kind of rainwater storage tank has been stipulated to hold back the downpours from inundating drains. So why not use this rainwater constructively in the home and outside? A system can perform the double role of reducing mains consumption and offsetting flood damage. The bigger the tank the more you will gain from using rainwater We already use small water butts to water our gardens. But a 200 litre butt will not give much protection in a drought. You can easily take the step to installing bigger tanks, typically between 2000 and 7000 litres. In doing so, you can protect yourself against water shortages for all outdoor uses. With some extra investment, you can use rainwater for WCs and washing machines and reduce mains water use by about 50%. 2

3 We offer a range of tanks adaptable to different locations: wall tanks that fit neatly against the house, slim tanks (the Water Hog) that take up little space, feature tanks that disguise their function as a wall or rock, and much larger tanks that can be installed above or below ground. Most of our tanks and accessories come from Germany where rainwater harvesting has been well-established for several years. Components of a rainwater harvesting set-up : 1. A water butt (normally thought of as a smaller one located at the down pipe from the roof) or storage tank (of larger capacity located above or under ground) 2. A filter-collector is installed in the down-pipe from the roof gutter; leaves and debris continue down the existing drainpipe while clean water flows to the butt or tank. Filtering out the debris prevents the water becoming smelly and brackish and stops sludge in the bottom of the tank clogging tap outlets, hoses and watering heads. Some filters separate debris out and send it on down the drainpipe while clean water comes out of the side. Other filters eject debris straight out the side (picture right), while cleaned water flows down the downpipe into the tank. Both kinds are easy to maintain. In larger tanks installed underground, the filter normally sits in the top of the tank itself (ground filter) rather than in the downpipe (downpipe filter). 3. An overflow siphon in the water tank creates an occasional rapid flow of water off the top of the tank and sucks out smaller particles such as pollen which can accumulate on the surface. It also prevents vermin getting into the butt or tank as the orifice is so narrow. 4. A pump makes distribution from the tank easier by maintaining a good pressure (for sprinkling in the garden, for instance) and is essential if water is collected in a butt and transferred to a bigger tank at the same or higher level. Pumps with a pressure switch turn off the pump when pressure in the output pipe builds up. When watering the garden, for example, you can release the trigger to turn off your spray-head and the pump will momentarily stop running; you do not have to run in to turn pump off. 5. Most pumps also stop when the water level in the tank is too low for it to work any longer; this is done by a float switch. The rectangular blue component of the submersible pump pictured right, which is off in the picture (low water level) and which turns the pump on when it floats vertically above the pump (high water level). 6. The floating pump intake, picture right is attached to the inlet of a submersible pump to ensure that only the cleanest water from the middle of the tank enters the pump. Although most pumps do have their own filters, they perform much better if the rainwater has been filtered already by an exterior filter. 3

4 7. The Calming Inlet, lying at the bottom of the tank and fixed to the inlet pipe, prevents any debris accumulated on the tank bottom from being disturbed by water flowing in. 8. To use rainwater inside the house a mains back-up system is necessary in case the tank empties. You may want a mains backup for outdoor use also, particularly if a timed irrigation system is connected to the rainwater tank. See paragraph 1.4 below for choice of 3 options. All options must safeguard against any rainwater ever entering the mains drinking water network, which is required by Building Regs. 9. There is a trend towards in-home systems which manage the rain water better and reduce pump electric use and wear. See 1.4 below 1. HOW TO USE RAINWATER Garden Systems Household and Garden systems How a rainwater harvesting system works Mains Back-Up Options What Size system will you need? Installation Maintenance Options the best lay-out for your requirements 1.1 Garden Systems A standard 200 litre water tank in the garden will fill 20 standard 10 litre watering cans: maybe enough for a small garden in normal condition, but in any kind of drought, it will quickly run out. We would recommend larger tanks, as they will give you greater watering flexibility in dry periods, and enable you to wash the car, use the pressure cleaner and fill the pond (fish like rainwater not chlorine) and the swimming pool. For those who do not have the space for larger tanks, our 650 litre rectangular tank (a pair of them in kit form pictured, right) fits well against a wall or fence. For those with the space, we have tanks ranging from 1600 litres to 10,000 that can be installed either above or below ground. Drip-watering equipment: it has long been known that installing a drip-watering or trickle feed system is much more economical in water usage and better for the plants than sprinkler systems. We give more information in this pack. Choose a system from your garden centre best adapted to keeping your favourite plants well-watered. 4

5 We supply all the accessories needed, such as connectors for storage tanks to fit into house or shed drainpipes, and pumps to create a better flow. Remember plants prefer rainwater to mains water: it is softer and has no added chemicals like chlorine. 1.2 Household and Garden systems Installing a much larger tank capturing rain from a full roof has two advantages; 1) it provides more security for the garden in drought conditions and 2) can also be used to clean cars and even to supply WCs and washing machines. Typically, an average household will need at least a 3000 litre tank or bigger (our 6500 litre tank is a bestseller). These larger tanks are can be installed either above or underground. It is easier to integrate a rainwater harvesting system into a new house, but it can, with minimal plumbing and guttering work, be added to an existing home. 1.3 How a professional rainwater harvesting system works Ideally we should all have a full rainwater harvesting system, so that we can use rainwater in the home as well as in the garden. We all see water tanks in the garden as obvious but the thought of using rainwater in the home seems a radical move. In fact, installing a rainwater tank for using with WCs and washing machines is relatively straightforward, although we do not advise these as do-it-yourself installations for a typical householder. Tanks can be installed either above or below ground. This is how a professional system works. Rainwater is first cleaned by the filter unit which excludes leaf debris and other large particles Tank inlet is designed so that filtered water enters tank creating the least disturbance In the tank, heavier particles left sink to the bottom creating a beneficial biological layer. Lighter material floats to the surface A floating pipe intake ensures that the cleanest water in tank is drawn to the pump A pump takes the rainwater from the tank Overflow pipe takes excess water to soakaway or is connected to existing drainage system. 1.4 Mains Back-Up Options Plants prefer rainwater: softer, no calcium, no added chemicals A mains back-up facility is essential when using rainwater to supply WCs and the washing machine. currently offers a choice of three options. 1) A float switch in the tank connected to a solenoid valve. This is the cheapest solution and is a solenoid valve which is activated by a float switch in the tank. If the level drops too low, this valve will allow just enough mains water into the tank to feed the appliances but not fill the tank completely. The pump in the tank works independently. To comply with Building Regs, a tundish fitted below the solenoid valve will create an air barrier between rainwater and drinking water pipework. This ensures no rainwater can enter the mains system and also provides a visible means of checking if the valve has stuck open. 5

6 2) A rain manager has the pump, valve and a small tank in a unit usually placed in the utility room or garage. This system allows the small tank to fill with mains water when the main rainwater tank is empty, and this small tank then feeds the appliances. This unit allows easy access to the pump, but the pump will be activated every time a toilet is flushed. There might be some pump noise in the house. 3) The Rain Director with microprocessor-controlled roof-space header tank features minimal electricity use, less pump wear, water during a power cut, auto flush and holiday modes. The Rain Director has been devised to reduce pump use and, therefore, energy consumption. As most rainwater used inside the home will be used to flush toilets, the pump normally would be activated several times a day to fill cisterns. With a Rain Director, the pump in the rainwater tank fills a rainwater header tank in the loft space which in turn gravity feeds WCs and the washing machine. The pump is only activated when this header tank empties. The Rain Director also incorporates an automatic mains back-up valve if the main storage tank runs out. This valve can be manually operated during a prolonged power cut when the pump won t be working. The pump is located in the underground tank so there is no pump noise in the house. 1.5 What Size system will you need? You can find out free of charge what size system you ll need. You just tell us some basic facts about your household and Rainwater Harvesting will advise you on the most suitable system for your needs, including the tank size and prices. You need to tell us: Your house s roof area (in square metres) Garden area (in square metres) and/or the area which needs watering Number of people in your household Number of WCs or expected number of flushes per day. Where you live (to help us ascertain the average rainfall in your area) Your water company Or work out your needs yourself using our tank size calculators on the website. 1.6 Installation a) Do-it-yourself installations Rainwater Harvesting will supply and deliver the components of your Rainwater Harvesting system but we do not install. It will require: 1. Feed pipes, small tanks: wherever possible specify or select pipes between the filter collector and the butt of 32 mm (1¼ inches) to be able to catch as much of a rain shower as possible. 6

7 2. Tank connections, small tanks: some tanks come with threaded holes (BSP not metric threads are standard even for the manufacturers from outside the UK) but most require you to drill the hole in the position (and of the size) you require. Some butts come with ¾ inch BSP threaded female holes into which you can screw the tap provided. Buy a complete kit if in doubt because then we can help you by phone or if anything appears to be missing. 3. Installation tools. If you are installing a butt up to about 400 litres or an array of smaller ones with a filter-collector in the downpipe at the level of the top of the butt, then arm yourself with the following tools: a) Spirit level, to get downpipe cut at the right height. b) Pencil or felt-tip pen to mark the downpipe at the level to be cut c) Saw (tenon or hack) to cut the downpipe where the filter- collector goes d) Knife to cut plastic pipe to length Cordless drill and hole-cutting set (unless butt is supplied with a cutter) e) PTFE tape or silicone sealant to make connectors to tank waterproof (optional) 4. Piping: if one or more water butts feed a bigger tank, plan where the feed pipe runs and dig it in if possible. 5. Maintenance. The inlet filter will need cleaning every 2 or 3 months. If and when the butt is empty at the end of summer, clear any debris which might have accumulated in the bottom. If you are using narrow pipes like hose to connect tanks then make sure they are clear, every few years, by blowing through with water or air under pressure. b) Professional installations For an underground tank supplying appliances in the home, you will probably wish to use a local professional (building contractor, landscape gardener, handyman or plumber) to do your installation. Get the right fit for small tank pipes and connectors with the following conversions: ½ inch: 13 mm ¾ inch: 19 mm 1 inch: 25 mm 1¼ inches: 32 mm Underground installation. If the ground where the tank is to be installed is well drained and has a low water table, back filling with sharp sand, earth or pebbles is OK. A 150 mm thick concrete base will also be needed. Full manufacturer s instructions come with the kit. You can click here now to download it. If the ground is habitually wet or the water table is high, there must be a beam or concrete to prevent the tank when empty from popping up out of the ground. Alternatively, drain the area directly around the tank with a pump if needed. MDPE tanks are not normally strong enough to keep their shape in compression so the tank must be filled with water as you proceed with backfilling. Pipe sizes: There is space on the tank for you to cut holes as required for connecting the filter inside the turret etc. We recommend use of British standard 110mm brown piping (more accurately 4.25 inches or 108mm external diameter) as supplied by builders merchants like Jewson, Wickes etc. If you are using 110mm piping between your roof's downpipes and the tank, and between the tank and the drain or soakaway, then you have no worries about compatibility of pipe sizes. Overflow. For underground tanks, the overflow can either be connected to the drain or into a soakaway. Plumbing. If you are going to use rainwater for toilets and washing machine then a supply network separate from the mains pipes will have to be fitted by a plumber. 1.6 Maintenance 7

8 Rainwater Harvesting systems normally need little maintenance. The Graf Optimax filter in the turret of the Carat underground tank, and those from other manufacturers which are not basket filters, feature a nearly-horizontal mesh filter from which the leaves are washed away by the arriving rainwater. Ensure when installing the tank that the debris outlet (which doubles as the tank's overflow) has enough drop to ensure a good flow of water away from the filter towards the soakaway or drain. Other filters may require checking from time to time. Some sediment will build up in the tank bottom but it could be 4 or 5 years before any any intervention is required. To get the silt out, lower a dirty water pump to the bottom of the tank when it's nearly empty and pump out the silt with the remaining water. A hose or pressure washer could also be useful. Even if silt does start to accumulate, there 3 devices which ensure a clean water intake from the tank: a) The calmed inlet prevents arriving water from disturbing and silt. b) The siphon on the overflow sucks dirt of the surface of the water c) The floating intake takes rainwater for the house from just below the surface of the water, where it's clean. The pumps in the 200 range are strong and long-lasting. They require no maintenance and, being submersible, there are no user-serviceable parts. In the case of breakdown the pump can be pulled out with its cord (the top of which is attached to the inside of the tank turret at installation) and replaced. Check with your supplier about the guarantee involved. 8

9 1.6 Options for Rainwater System Layouts These options show various basic layouts. These can, of course, be adapted to your particular needs and budget. Option 1 Simple water butt Accessories needed are a downpipe filter and connectors. The tank pictured is the 1600 litre Hercules (GF ). Smaller tanks include a 750 litre rectangular tank and a 300 litre tank that actually looks like a wall. See for details. Pump and water flow Filter Usage Capacity None required Recommended Leaf filter on downpipe Trickle or watering can 200 to 1600 litres. Limited drought protection depending on garden size Option 2 - Surface storage tank with pump and downpipe filter For more capacity, and if there is somewhere where a tank would not be an eye sore, use a larger tank from our range. This is a good solution for premises such as stables and poultry farms.pictured here is the Balmoral tank 5455 litre Complete System 1 Product ID: BWST- V5455-GAK1 Pump and water flow Filter Usage Capacity Electric pump at storage Leaf filter on downpipe. Garden watering, car 1,000-30,000 litres. tank to give hose washing, pressure hosing Summer long garden pressure on demand and other outdoor uses. water. No loss of water from sudden downpour 9

10 Option 3 - Small butt and surface storage tank with pump Where it is impractical to put a large tank near the roof collecting the rainwater, a small tank can be located near the roof and the large tank placed at a distance. Pump and water flow Filter Usage Capacity Electric pump at house Best with leaf filter on Tap, irrigation supply, 1,000-30,000 litres. tank with float switch and downpipe and floating trickle or watering Summer long garden pump at large tank to intake on the large tank can. Power washing, pond water. Some loss of water deliver pressure at the hose or tap. outflow. top up etc from sudden downpour Option 4 - Small butt with pump and storage tank at higher level with or without pump Suitable if a large storage tank can be placed on high ground. Then there is no need for a second pump to take water from large tank for distribution. Pump and water flow Filter Usage Capacity Electric pumps at house Down-pipe water filtration Can deliver water by 1,000-30,000 litres. tank and at large tank to preferable and floating gravity or under pressure Summer long garden give hose pressure on demand. intake at the large tank. with pump. water. No loss of water from sudden downpour 10

11 Option 5 - Below ground storage tank Putting the tank underground is the preferred solution but incurrs the extra installation cost. You can weigh up the arguments for and against underground installation. 1) in favour of digging the tank in: a) No unsightly equipment in the garden, especially if you are installing a tank bigger than 200 or 360 litres b) Suitable for a small garden or where the space is otherwise restricted. For example, our stronger tanks can be installed under a drive way if suitable supports are constructed over the tank c) Less risk of brackishness in summer due to warming of the leaf debris at the bottom of the tank. However, a properly filtered system will not be subject to leaf debris and brackishness in any summer conditions. d) Negligible risk of frost damage to tank, piping and pumps in winter. 2) in favour of situating the tank above ground: a) Cheaper and easier installation costs b) Easier to maintain in case of change of scenario or pump failure c) Suitable for farm, outhouse, stable and other installations where the visual and aesthetic criteria are less important Pump and water flow Filter Usage Capacity Leaf filtration on downpipe and/or filtration at entry to storage tank Large underground tank fed by downpipe. Pump in storage tank is essential to deliver pressure at the hose. Hose for garden, car washing and irrigation systems. No winter freezing, less risk of brackishness. 1,000-30,000 litres. Summer long garden water. No loss of water from sudden downpour 11

12 Option 6 - Complete domestic system Pump and water flow Filter Usage Capacity Undergound or above Extensive filtration ground tank with pump required. Building and controls to ensure regulations apply. water can be available for garden and limited domestic use. Return pipe supplies secondary piping in the house for WCs and washing machine. Mains back-up required 1,000-30,000 litres. Round the year household and garden water us for further technical details at info@rainwaterharvesting.co.uk 12

13 2. WHY WE MUST USE RAINWATER The World s most precious resource Water Facts How to gain from rain Saving the World Save yourself from droughts Reduce your water use 2.1 Making the most of the world s most precious resource. In the UK we are complacent about our water. Our water is cheaper than in many countries and only 22% of domestic properties are metered. It is a tradition for our European neighbours to mock us for our wet summers. Yet in fact the UK is classified as a country with insufficient water. With population growth and therefore the need for more housing, demand for water is rising. Madrid and Istanbul have more water available per person than London. An October 2008 report by the Environment Agency warns that Britain s rivers, which provide 70% of our water, will drop 10 to 15% in volume within 40 years. Householders need to reduce water consumption by a third. Global warming is accepted now whether man-made or cyclical, and so we must make the best use of our precious water and prevent the situation deteriorating. Rainwater harvesting has a significant role to play in doing this. The Code for Sustainable Homes which came into force in May 2008 encourages the installation of rainwater harvesting. This Code assesses homes for sustainability in 9 categories, including 2 to do with water. One aims to reduce drinking quality water consumption and the other to reduce flood risk. Currently 30 to 50% of the 160 litres of water each person uses a day need not be drinking quality water. Using rainwater from our own roofs would greatly reduce consumption. Collecting rainwater also contributes towards avoiding floods. Social housing now has to meet level 3 of this Code, targeting a daily use of only 103 litres per person per day. But whether as a householder or a concerned professional, we can move ahead on our own account without waiting for official rules and regs. And whether with a 200 litre water butt to water seedlings or a litre storage tank linked to the home, we can all maximise our use of rainwater and relieve the water shortage in this country. 2.2 Water Facts Imagine yourself in swimming in a pool 7 metres long, 4 wide and 2 deep: not a big pool but large enough to take some good exercise. It contains the amount of water it is estimated you use every year in the UK: litres or 160 litres a day. How do we manage to use so much? 13

14 Water Use in the home Average Bath 100 litres Average WC use daily 50 litres (old WCs use 9 litres per flush, new dual flush 4 or 2.5 litres) 5 min shower 33 litres (more like 100 with a power shower) Leaving tap running eg washing up or cleaning teeth. 5 to 10 litres a minute Dishwasher load litres Clothes washing load litres Water Use outside the home And so that s about 160 litres down the drain before even going in the garden. Normally outdoor use of water is only 7% of water consumption. But at peak times in a dry summer this rises to 70%. The hosepipe is the villain. Depending on use, it flows at around 1000 to 1400 litres an hour. Connected to a sprinker, it is a wasteful and ineffective way of watering. Using a trickle or drip system is a much better way: water is absorbed slowly and penetrates more easily to roots, there is no evaporation, and it can be directed to specific plants. And on average a 100 metre length only uses 55 litres an hour. So with toilets and the washing machine using between 30 to 40% of our water, it makes sense to use rainwater instead of mains water to supply these appliances. And in a drought when we want to use so much more water for gardens and other outdoor uses, it makes sense to use stored rainwater when mains water use might be restricted. 2.3 How to gain from rain (or What s in it for me? OK, so at long last more and more of us are realising that our water is precious. The UK has been spoilt so far: we have had cheap and plentiful water, but this is changing. We need to use water more efficiently. But however green we are, we all want to know how much it will cost us and save us. Costs obviously vary depending on individual needs and whether the collected rainwater is to be used just for outdoor use (irrigation, 14

15 outdoor-cleaning) or inside the house as well for supplying WCs and washing machines. For rainwater use in the house, separate rainwater supply pipes to the appliances are needed making installation more cost efficient in the context of a new build or a renovation project. And if the tank is to be underground, then the hole has to be made. However, this need not be expensive in comparison to the overall cost of the building or renovation project. The gains. The investment will be worth it. In August 2008, ten water boards applied for price increases that could lead to a 40% rise in water bills within 5 years. Using rainwater in combination with a metered mains water supply makes it more and more realistic to save on water bills. In addition, investment in a rainwater harvesting system could increase the value of a new or renovated home by many times the cost of the initial equipment. Purchasers view sustainable options such as rainwater harvesting as an attractive and necessary addition to the contemporary home. And the larger the tank installed, the more chance of continuing irrigation during mains water shortages. And at long last the official pressure is on to use rainwater: The Code for Sustainable Homes which became mandatory in May 2008, assesses homes for reduction in drinking water consumption and flood risk. All social housing must be built to Code level 3, reducing daily consumption from 160 to 103 litres a day. Private housing does not have to meet this level but a rating is compulsory and must be included in the Home Information Pack. A nil rating will not attractive to potential purchasers. Planning applications with rainwater harvesting are favoured. Planning regulations changed in September 2008 to encourage use of permeable surfaces and rainwater harvesting to offset flood threats from hard standings round houses. All new homes must have meters and water boards must install meters free of charge to existing households. Records show that metered homes use 10% less water; having a meter and using rainwater could reduce your water bill. Businesses can benefit from the Enhanced Capital Allowance scheme to offset the installation cost of rainwater harvesting against tax Businesses have a tax incentive (see above) and in the future the Government should implement grants such as exist in Germany where in some areas a grant of 1000 is given towards the cost of installation. Germany now has rainwater harvesting systems installed every year ( in total). A 2003/04 survey of English Housing found that 18, households have a garden, patio, yard, roof terrace or large balcony: just think how much water we could save if everyone used rainwater! 15

16 2.4 Save the World Are you frustrated that governments, international agencies and leaders seem unable to do anything about global warming, the depletion of our natural resources or preventing natural disasters? Would you like to do something about it yourself? Maybe it s the time to stand up and be counted. Express your individual responsibility for the destiny of the world. You are probably already co-operating with your local council in recycling as much waste as possible. You have double glazed the windows, increased insulation and turn lights off whenever possible to reduce your energy consumption. Are you thinking about solar or wind energy? Yes, but there seem to be some obstacles, not least of which is how little the sun shines in the UK at the times you need the energy. Now things are a little bit clearer for rainwater harvesting. We have high levels of rainfall. Collecting it is simple from an engineering and planning point of view. So you have a simple means of reducing your dependency on the mains water supply, and increasing your protection against the effect of droughts on your garden watering, car-washing and other domestic use. You don t need to use drinking water to flush your toilets or supply your clothes washing machine! In fact in an average home 45% of domestic water use does not need mains water at all rainwater is fine. Put it another way. Does it seem ridiculous to you that a money-making conglomerate processes water centrally, pipes it huge distances to get to your house, and loses a high percentage from pipe leaks on the way? What a waste of energy. Then you dump 99% of it down the drain when you ve used it, to be piped back to that same company in a sewer. Most homes in the UK will soon have a water meter, so they ll be charging you for what you use. Why not process the rainwater from your own roof, use it around the house, and reduce your dependency on the water company. Whatever your feelings on the environmental and economic issues, you can take simple steps today to use your own rainwater. The simple act of installing a water butt in the garden will not only give you water for the garden when it s dry but will reduce you use of mains water for watering the garden. Or take a bigger step and ask us to calculate the cost of a built-in system, header tank in the roof, and piping to be able to reduce mains water consumption in the house. 2.5 Protect yourself from droughts Rainfall in the UK varies between 550 and 3000mm a year. However, the high rainfall tends to be in the north and west where few people live. Most people live where rainfall is between 600 and 800 mm a year. London is actually drier than Istanbul and Madrid. In fact it is predicted that it will become wetter in the north and west, and drier in the south and east. The Environment Agency has concluded that the south and east are already past sustainable levels. The summers of 2007 and 2008 were among the wettest on record. But the summer of 2006 was the driest on record, preceded by a dry winter, resulting in the well-publicised water restrictions. This motivated the Government to introduce new legislation (not in force yet) which will give water boards greater powers during water shortages. Hosepipe 16

17 bans will extend from just watering gardens and washing cars to include filling swimming pools, ornamental ponds and hot tubs, and cleaning patios, drives and windows. But with a water tank and an effective irrigation system you could keep your garden going throughout a drought. For example, with a 5000 litre tank and a 100 m long drip system, you could water for an hour a day for 90 days before the tank ran dry, with 1500 litre tank, 30 days, and with a 650 litre tank 10 days. 2.6 Reduce your water usage Even if you install a rainwater harvesting system, this should not stop you trying to reduce your water use. Here are some tips from susie@rainwaterharvesting.co.uk In the garden: Use a drip or trickle system directed to specific plants rather than a sprinkler: a sprinkler uses 1000 litres an hour whereas a 100m length drip system uses 55 litres an hour (Hozelock consumer info). The RHS figures say that an irrigation system uses up to 75% less than a standard sprinkler so take your pick on the stats. Use a timer Never water in the heat of the day: evaporation will reduce the moisture rapidly, and the plant may even be worse off Put as much compost or mulch as possible round the base of plants to conserve moisture When planting shrubs and fruit trees, put a 30 to 40 cms length of hosepipe into the ground next to stem so that when watered down hose, moisture reaches roots For smaller plants and vegetables, dig in a small flower pot next to them which allows water in it to percolate slowly down to roots Round any plant, shrub or young tree, build up a shallow circular ditch round stem, so that water will stay rather than flow away at once. This is particularly necessary on slopes Gently break any hard soil surface round a plant (taking great care not to disturb roots), so that water can get in Cut lawns less frequently and with a higher blade in dry conditions. And remember that however brown it looks, it will recover. Resist the temptation to use a sprinkler! In the house: Have a shower instead of a bath, and use 33 litres (for a 5 min shower) rather than 100 litres. Watch out for power showers though: nearly 100 litres for 5 mins!) WCs. Old WCs 9 litres per flush. Put plastic bottle in cistern to reduce flush volume. New dual flush WCs use 4 or 2.5 litres per flush Don't leave taps running: 5 to 10 litres can vanish in a minute while you wash your teeth or rinse fruit. 17

18 Replace worn washers: a dripping tap can waste 15 litres a day ( Think before you turn on the hot tap: a litre or 2 can flow away while you're waiting for the hot water to come through. And a hint that's a pleasure to follow! Fully load a dishwasher rather than wash by hand Product ID: RWH-SP-K01 Solar Pump starter kit The Solar Powered Pump kit from RainWaterHarvesting.co.uk enables you to use rainwater in the house and round the garden without using mains electricity. This kit should be used with a header tank, for example in the house s roof space, to which the pump transfers water from the rainwater tank over time. It s also useful for moving water from a collecting tank in the garden to a storage tank at a higher level. 18

19 FREQUENTLY ASKED QUESTIONS To search for a word or phrase use your browser's search function (Control F). 1. About Rain Water Harvesting 1.1 What is rainwater harvesting? It is the collection from roofs and storage of rainwater that would otherwise flow down gutters into the drain or a septic tank. Rainwater is stored in tanks ranging from 200 litres 20,000 litres, with the most popular for detached family houses at 6,500 litres. The rainwater is not considered potable by the UK Building Regulations but the state-of-theart filtering provides clear water which is used for drinking in many parts of the world. Water can get brackish if stored above ground where it is subject to summer warmth; digging the tank in underground where the water stays clear, is therefore essential for rainwater to be used in the house for flushing toilets and washing clothes. Your tank kit typically comes with filter, pump and other standard equipment to keep collected water clean. The larger the tank you have, the more money you will eventually save and the more protection you will give your garden during droughts and possible hosepipe bans. 1.2 What can you use rainwater for? Rainwater can be used for all outdoor uses: watering the garden, washing cars, cleaning patios, drives and windows, topping up swimming pools, ornamental ponds and hot tubs. With some plumbing alterations, it can also be used inside the house to flush WCs and feed clothes washing machines. Besides saving on drinking water use, rainwater use encourages less build-up of calcium deposits in appliances. The diversion of rainwater to the storage tank can in many situations attenuate flooding. 1.3 Why should I use rainwater? Each person in the UK uses about 160 litres of drinking quality water a day. Nearly half of this amount need not be drinking water. It seems crazy to bring in drinking water from miles away via your water board to water your garden or clean your car when you could provide water directly from your own roof. It is now recognised that the south east of England in particular is short of water (London has less water available per capita than Madrid or Istanbul). April 2007 was the driest on record, but then June 2007 was the wettest on record. That's when the wags started asking when the hosepipe ban would start! The more water you can collect in wet spells, the more you will have when it's dry. 1.4 Is rainwater better than drinking water for outdoor use? Your garden will prefer rainwater to tap water because it does not contain the chemicals needed to make tap water drinking quality. And when using a cleaning agent, you will need to use much less, again because there are no chemicals and the water is softer. 1.5 How will rainwater harvesting help me during a hosepipe ban? In 2006 many areas had hosepipe bans banning watering gardens and cleaning cars. New legislation will give water boards the right to prohibit using hosepipes for other outdoor cleaning purposes such as washing boats, patios, drives and windows, and also for filling swimming pools, ornamental ponds and hot tubs. 1.6 Will I save on my water bill if I have rainwater harvesting? You can save on your water bill if you have a meter. Government reports estimate that 70% of customers see their bills reduced with a meter by 10 to 15% because of the user's awareness that mainswater costs money. Most water boards have ready-reckoners on their websites to help you decide whether a meter is a good idea. Currently only 19

20 around 23% of households in the UK have meters, but they are obligatory in new builds. You water board is also obliged to fit you one if you request it. 1.7 If my water is not metered already, can I ask to have one installed? Yes, all water boards have to install a meter at the request of the householder. Installation is free, and some boards provide the meter as well. Some water boards insist on installing a meter with change of ownership, and sometimes, in tenancy of a property. 1.8 Will I save on my water bill if I have rainwater harvesting? Typically half your water bill is for mains water supply and half is for drainage. MOst calculation of rainwater use for flushing toilets and washing clothes shows that water consumption can be halved. This would therefore knock about 25% off your water bill. In august 2008, 10 water boards applied for price increases that could lead to a 40% rise within 5 years; savings will become more significant. 2. Planning my rain water harvesting system 2.1 Does the tank have to be underground? For domestic water use, yes. You should weigh up the arguments for and against digging your tank into the ground 1) in favour of digging the tank in: a) No unsightly equipment in the garden, especially if you are installing a tank bigger than 200 or 360 litres b) Suitable for a small garden or where the space is otherwise restricted. For example, our stronger tanks can be installed under a drive way if suitable supports are constructed over the tank c) Less risk of brackishness (discoloration due to bacterial action at 12 degress C and above) in summer due to warming of the leaf debris at the bottom of the tank. d) Negligible risk of frost damage to tank, piping and pumps in winter. Take into account the prevailing temperature conditions in winter where you live; if your pond or water trough freezes up seldom, and if the layer of ice is only a few centimetres thick at worst, then your rain water harvesting tank and equipment are unlikely to be damaged. 2) in favour of situating the tank above ground: e) Ease of installation and lower installation costs f) Easier to maintain in case of change of scenario or pump failure g) Suitable for farm, outhouse, equestrian, market garden and other installations where the visual and aesthetic criteria are less important. 2.2 Do I need a large roof area to provide an adequate supply of water? A surprisingly small roof area will give a lot of rainwater: a typical terraced house with a 6 by 8 metres roof area could give 30,000 litres a year depending on the area of the country you live in. Check the tank size calculator and UK rainfall figures on the web site. 2.3 How long would the water last in a drought? Check the tank size calculator on the web site. You can calculate from the size of your roof and average rainfall figures in your area (available on our web site) how much water will come off you roof in a year. The same calculator works out how long the water will last in a drought from a) your garden size, b) how much water you want to give to your plants, and c) the size of your tank. Aim for between 1 and 4 weeks drought protection and a tank size which also suits your budget. 2.4 What else do I need besides a tank? 20

21 The filter installed in the pipe to the tank is essential for larger tanks where water may be stored for a longer time. It will help prevent water becoming smelly and discoloured by removing leaves and other debris. This also reduces the sludge accumulating at the bottom of the tanks, and reduces clogging of tap outlets, hoses and watering-can heads. High quality filters (such as in the turret of the tank) separate debris out and flush it down the drain or soakaway. Some downpipe filters eject debris straight out the side, while cleaned water goes into the tank. Both kinds are easy to maintain. For even cleaner water, an overflow siphon collects smaller particles such as pollen which can accumulate after filtering on the top layer of rainwater. The integrated u-bend stops vermin getting into the tank through the overflow outlet. Where the rainwater flows into the bottom of the tank, a calming device prevents the flow from stirring up any silt on the bottom. A floating intake to the pump takes water from the cleanest place, a few centimetres below the surface. A pump maintains a good pressure and flow of water round the house and garden. Pumps (such as the Forta Duo and similar pressure-sensitive pumps) turn on automatically when you turn on a tap or flush a toilet. It stops on its own as well. Other less expensive pumps will only stop when the water level in the tank is too low for it to work any longer. Although some pumps do have their own filters, they perform much better if the rainwater has been filtered already by an exterior filter. 2.5 Why is it a good idea to install a filter and pump if I am only using rainwater for the garden? A filter installed in the down-pipe to the tank, or in the top of the tank itself, is a good addition for all tanks but is particularly to be recommended for larger tanks installed above ground where water may be stored for a longer time. It will help prevent water becoming smelly by removing leaves and other debris. This also stops sludge accumulating at the bottom of the tanks, and tap outlets, hoses and water-can heads clogging up. Some filters separate debris out and send it on down the drainpipe. Other filters eject debris straight out the side, while cleaned water goes into the tank. Both kinds are easy to maintain. A pump makes distribution from the tank easier by maintaining a good pressure. Quality pumps (such as our Forta Duo pump) with a pressure-sensitive switch turn themselves off when water flow is not needed; when using a spray-head, you do not have to run in to turn pump off: it will stop when you click the spray-head to off. Other less expensive pumps will only stop when the water level in the tank is too low for it to work any longer. 2.6 What is the best kind of pump to use? Pumps (such as our Forta Duo pump) with an automatic pressure switch off and which can be used both in and out of the tank are the best. These allow you, for example, flexible watering. When using a spray-head, you do not have to run in to turn pump off: it will stop when you click the spray-head to off. Other less expensive pumps will only stop when the water level in the tank is too low for it to work any longer. 2.7 What size pipes should I use? a) Butts and tanks 1000 litres or less, do-it-yourself systems: It is tempting to use a small diameter pipe (hosepipe or 25mm (one inch) diameter from the collector-filter to the tank. However it is worth the effort to use 32mm pipe to the tank. A narrow pipe will collect the bulk of water from light rain and drizzle, but during the critical period of collection, i.e. the summer, you need to be able to catch the available water which typically falls in sudden storms at that time of year. So give yourself a chance by fitting the biggest pipe possible. In our experience, 32mm is the best. Try to buy usually Spiroflex or a similar pipe which keeps its shape (transparent tubing from a DIY shop twists and caves in, restricting water flow, so avoid it). You can get Spiroflex from any aquatic or fish pond supplier, often in the back of your garden centre, or order it from us. The connection kits are available separately on request. 21

22 b) Tanks larger than 1000 litres and all underground tanks, professional systems : Rigid drain-pipe is recommended, in either of the two 75mm or 100mm diameter standard sizes, so that the flow is unrestricted and so that the weight of earth or backfill does not collapse the pipe. Installations of this sort would normally be installed by your contractor or plumber. In both cases, make the pipe from the tank to the appliances or garden taps as wide as practical, certainly not less than one inch (25mm) diameter. 32mm is preferable to maintain a good flow rate and pressure for garden sprinkling. Use MDPE pipe with push fittings; use black pipe not blue to indicate that the rainwater is non-potable under the UK Building Regulations. 2.8 When do I need to use a filter? A filter is recommended in every Rain Water Harvesting installation and essential if the rainwater is going to be used in the house. It is most critical when leaves often fall on the roof being used, such as a low roof with trees nearby. 2.9 What is the best filter to use? RainWaterHarvesting.co.uk sells three types of filter. 1) The down-pipe filter/collector takes the water feed for your tank through an outlet in the side; the leaves or other debris continue down the existing down-pipe from your gutter. Use this next to the house when adapting an existing down-pipe. When the tank is full, excess water flows on down the down-pipe. 2) The leaf extractor filter (e.g. Rainus filter) pushes leaves or other debris out of the side of the filter and the clean water continues down the down-pipe. Use this type on out-houses, garden garages, stables etc when the down-pipe goes straight into your harvesting tank and when you don't mind leaves being pushed out the side. 3) Underground tank kits come with a professional self-washing filter, like the Optimax Pro, fitted in the turret of the tank. Leaves are pushed by the water flow out into the waste pipe Is there a risk that the down-pipe filter will cause a back-up spill over the gutter? Both down pipe filters and leaf extractors have overflow capacities as big as the original down-pipe to which they were fitted. You might get back up of water and overflow at the level of the gutter, but only in such extreme rain fall that you would probably have had gutter overflow anyway Why do I need a siphon? The siphon skims small particles of dirt off the top of the water by creating a more rapid water flow from time to time. This is rather like the flush of a toilet but on a smaller scale. It keeps the water in the tank cleaner than a plain overflow pipe Can I use a small butt near the house feeding a larger tank elsewhere? Yes. You can have a small water butt (say 200 litres) collecting rainwater off the house down-pipe. As it fills, an automatic level-sensitive pump sends the water through an above-ground or buried hose-pipe or 1 inch pipe to a much bigger storage tank underground or elsewhere on your property. You should plan for a soak away to handle excess water at the storage tank What is the best way to distribute water from the storage tank? You can 1) Fill a watering can from the tank, 2) Use hose or tricklers fed by gravity from the tank. 3) Use a level-sensitive pump which stops when the level in the tank drops to a pre-determined level. 22

23 4) Use a pressure sensitive pump which turns off when it senses back pressure in the pipe it's feeding, e.g. when you close the sprinkler or tap with which you are doing the watering Can I use a lawn sprinkler with my rainwater harvesting tank? Yes, but you'll empty the tank rather quickly. A normal movable sprinkler can use 1,000 litres per hour, so a 200 litre tank would be empty in 12 minutes! We recommend the use of a drip feed system (such as those from Gardena and Kar) where water is directed to the roots of the plants at night, controlled by a time switch. The lawn should be watered with mini sprinklers for a few minutes daily if required, i.e. consider fitting a soil humidity gauge Am I obliged to put my water butt on a pedestal to get the watering can under the tap? No, if you are going to use a pump. And even without, attach a short length of pipe to the tap and water will flow into a watering can or bucket until the level of the water in the butt is lower than the level you want in the can Does all rainwater harvesting equipment come with all the right connectors? In a word, no. We have been surprised at how lacking in diligence most of the manufacturers have been in this respect. Here at RainWaterHarvesting.co.uk we make every effort to inform buyers what they're getting and we'll source and provide any extra bits needed. If you buy hose, try to use 32mm spiral reinforced (25 or 32mm black MDPE for domestic supply). Flow is better and connectors easy to get Can I use rainwater in my pressure cleaner? Yes but with a suitable pump. Most pressure cleaners, like the Karcher, need a certain amount of pressure and flow rate of the water at arrival. We have found that the small pumps in the range do not deliver enough pressure, but better ones like the Forta Duo work fine. Look for 500 to 1100 watts in power and 3 to 5 bar pressure. Such cleaners use a lot of water so check the tank level before use (normally by lifting the cover and looking) Can I use rainwater to fill a swimming pool? Yes. Use an underground rainwater harvesting tank, pump and filters to ensure that the water being fed to a swimming pool is well clean. The Building Regulations are interpreted differently by different council inspectors: generally it is understood that rain falls into a swimming pool anyway, so using rainwater properly filtered provides an even better quality of water. Some inspectors like to insist on an Ultra-Violet filter which we can also supply. Check your alkali level and other water factors after filling with rain water. 3. Using rainwater in the house: domestic systems 3.1 Can I use rainwater in the house? RainWaterHarvesting.co.uk supplies all the equipment for domestic rainwater use. Select one of the kits which include the tank, filter, pump and accessories needed for such systems. Use of rainwater in the house requires you to plumb pipes to feed rainwater to the toilets, washing machine and one or more garden taps. The UK Building Regulations classify rainwater as non-potable so use in showers, baths and in the kitchen is not permitted in the U.K. - even though people in many countries of the world use stored rainwater for drinking. Do please check with local authorities about any other regulations that might apply. 3.2 What size tank do I need? 23

24 This depends on five factors; 1) where you live (amount of rainfall a year), 2) the roof area from which you can collect water to your underground tank, 3) the number of toilets and people in the house, 4) the amount of water you want for your garden and 5) how much drought protection you want. The tank size calculator on this website will help you work out your needs and RainWaterHarvesting.co.uk will check your calculations for you on request. The majority of tanks sold by us for a family house are 6500 litres in volume, i.e. the biggest of the Graf Carat range. If you're fitting a tank, why not fit the one which gives the best drought or hosepipe ban protection? 3.3 If I use rainwater in the house, what happens when my tank runs out? The automatic mains backup switches in, so you can go on flushing toilets and washing clothes without interruption. But you would not be allowed to water the garden when there is a hosepipe ban if the mains water is flowing. Remember to specify one of the three mains water backup options; a) float switch and solenoid valve on the mains pipe (a tundish (air gap) is needed to conform with Building Regs.) (cheapest option), b) a "rain manager" from various manufacturers with mini header tank and pump in a large console in your utility room, and c) The Rain Director with microprocessor-controlled roofspace header tank for minimal electricity use, less pump wear, water during a power cut, auto flush and holiday modes. 3.4 What is the power consumption of the "rain managers" like the Power Rain C or Graf's Silencio? Nominal working power consumption is 550w with a surge in power consumption each time the pump starts. The Rain Director uses about one eighth of the power because it lets the header tank empty by gravity before filling it again. 3.5 How loud are rain managers like the Power Rain C? 74 decibel unshielded or 70 decibel shielded. A dull hum. The Rain Director, on the other hand, makes no noise in the home because the pump stays submerged in the underground tank. 3.6 Can I collect grey water with a rainwater tank? Yes but... Grey water is waste water from the house (from basins, showers, baths, washing machine and dish washer) but not toilet wastes and food wastes derived from garbage grinders (called "black water"). It's mostly a question of personal taste whether to use grey water to water the garden, but if you are not a heavy detergent user, then, yes. Grey water should not be used to fill swimming pools and it might give a smeared finish when washing cars. You should consider a specialist treatment plant ( and you should also check any applicable regulations. We do not recommend putting grey water in your rainwater tank. If you have a big roof and plenty of rain you might choose not to bother with collecting grey water. 3.7 Is it better or easier to use rainwater than grey water? Rainwater is better than grey water as rainwater contains less detergents, soaps, chemicals and bodily dirt. But in times of severe water shortage you should try to store grey water for garden use. 4. Tank installation 4.1 What are the specifications and dimensions of the typical tanks? The vast majority of our sales are of the biggest Graf Carat tank which has a capacity of 6500 litres. You can see the tank manufacturer's brochure by clicking here: 24

25 You can see an engineering drawing of the tank with its dimensions by clicking here (or substitute the tank size for 6500 if your tank is other than 6500 litres): Why install underground? a) the low ambient temperature underground in summer prevents the water getting brackish and discoloured. For this reason it is not suitable to provide rainwater in the house from an overground tank. b) the tanks are big and ugly... not what you want in the garden from an aesthetic point of view. 4.3 If I buy a kit, what is included? The best way to purchase rainwater harvesting equipment is in kit form, i.e. with all the parts supplied to make a complete system. Our domestic water kits include not only the pump and filters but also one of the three types of mains backup; a) float switch and solenoid valve on the mains pipe, b) with a rain manager with built in pump and mini header tank in one unit and c) our new RainDirector with smart header tank and computerised control panel. Details at What is not included in the kit? Your contractor needs to supply the piping to connect a) gutter to tank (usually 4 inch gutter down pipe), b) the piping from tank to the house (MDPE black 32mm (1.25 inch) with BSP push fittings) and c) the internal piping to the appliances. 4.5 What building regulations are applicable? The client is responsible for complying with applicable regulations which can be interpreted differently in parts of the country. Most building regs for domestic use of rainwater require that a device must be fitted which prevents backpumping of rainwater into the mains system such as a tundish at the outlet of the mains to the tank. 4.6 Where should the tank be? The tank should be located convenient to a point where the downpipes from all four sides of the building can be brought together in one 110 mm drain pipe. This is usually the lowest point in the grounds if there is any slope. The pump will then draw water from the tank up to any point in the building. It should join the internal rainwater piping network in a utility room or the point where the mains water arrives in the building. 4.7 Can we use water off the drive and patio? We would not recommend using water off the hard standing or patio because oil spills or other waste could enter the water destined for washing clothes and flushing toilets. Some clients use a separate tank for run-off (and grey water) and this water is used on the garden only. 4.8 What are the installation requirements for a large underground tank? a) It is essential you follow the manufacturer's instructions for fitting or the guarantee will be void. The installation instructions of a typical kit are at nd_mains_backup.pdf 25

26 b) If the ground where the tank is to be installed is well drained and has a low water table, back filling with sharp sand, earth or pebbles is OK. You are advised by the tank manufacturers to provide a concrete base of 150mm under the tank. c) If the ground is habitually wet or the water table is high, there must be a beam or concrete to prevent the tank when empty from popping up out of the ground. Yes, it happens. Alternatively, drain the area directly around the tank with a pump if needed. d) MDPE tanks are not normally strong enough to keep their shape in compression so the tank must be filled with water as you proceed with backfilling. 4.9 I have a low-lying garden where water collects. Can I get it drained? Yes, use a dirty water pump with float switch from our range. Make a culvert or manhole at a low point in the garden into which surface water will flow. The pump starts automatically when water is present; you can route the outlet pipe up to a drain or soakaway Our rainwater tank is going to be so low that the overflow and leaf output have nowhere to go. What do I do? It is vital that the rainwater flows smartly over the filter in the turret of the underground tank so that leaves and debris are flushed away. If the top of the tank is lower than the drain then you need one of two solutions. 1) Make a soakaway with enough capacity to take both the excess water off the roof (tank full) and the leaves and debris. 2) Make a manhole beyond the outlet into which leaves and debris will flow. Use a plain mesh filter to keep the leaves on one side so that you can manually extract them from time to time. Beyond the mesh your soakaway absorbs the excess water. An optional pump in the clean side of the manhole starts automatically when water is present; you can route the outlet pipe up to a drain or soakaway. 5. Use of rainwater in the garden 5.1 Does my tank provide enough water to sprinkle the lawn? In a word, no. A sprinkler uses about 1000 litre an hour, so even if you use a large 6500 litre tank, it would be empty in a morning. We recommend the use of a trickle feed, soaker hose or irrigation system 5.2 What Irrigation system should I use? If you are watering flower beds and individual plants, then a leaking or soaker hose is the most water efficient. The water goes straight into the ground where it is needed. A typical leaking pipe uses 1 to 10 litres per metre per hour depending on whether it is 4mm or 12.5 mm diameter. Drippers (tricke feed) are water efficient also, directing water exactly to where water is needed. Fixed rate drippers use 4 litres an hour per dripper. Mini-sprinklers can be directed to specific areas and plants typically vary in range from 1.5 m, 2m and 3m, and use on average 55 litres per sprinkler per hour. For example, a 40 sprinkler kit covering 750 m2 would 2200 litres an hour. A typical spray sprinkler covering 240 m2 may not cost very much (eg 12.99) but is not water efficient, 1000 litres an hour. To water 750 m2 would therefore 3000 litres an hour, nearly a third more than the mini-sprinkler system. 5.3 How much water should I use and how often during a drought? The Royal Horticultural Society says that up to 24 litres per square metre every 7-10 days will be sufficient to maintain plant growth (ie 2.4 litres a day) or 2.5 cms of water per plant every 10 days during dry spells. For example, running a sprinkler system for 2 or 3 minutes every 24 hours should be enough during a dry spell. This is only a guideline as the water need will vary with the size of the plant. 5.4 Can I attach a hose to the pump in the underground tank? 26

27 In principle yes, but we recommend that the hose off the pump is a one inch (25mm) or larger pipe as far as a connector or stand pipe tap. This is because water flowing in the constriction of a half inch hose means that you do not get sufficient pressure and flow rate at the far end. 6. Maintenance 6.1 Do I have to clear the leaves out of the filter? No. The Graf Optimax filter in the turret of the underground tank, and those from other manufacturers which are not basket filters, feature a nearly-horizontal mesh filter from which the leaves are washed away by the arriving rainwater. Ensure when installing the tank that the debris outlet (which doubles as the tank's overflow) has enough drop to ensure a good flow of water away from the filter towards the soakaway or drain. 6.2 Doesn't leaf debris or sediment get into the stored water? As small amount, yes. Most tanks accumulate a millimetre or two a year, but there are 3 further devices in our kits which ensure clean rainwater in the home. a) The calmed inlet prevents arriving water from disturbing and silt. b) The siphon on the overflow sucks dirt of the surface of the water c) The floating intake takes rainwater for the house from just below the surface of the water, where it's clean. 6.3 Should I clean the sediment out? The tank manufacturers mostly say you should inspect the tank for silt build-up every couple of years, but it can be much long before any intervention is required. To get the silt out, lower a dirty water pump to the bottom of the tank when it's nearly empty and pump out the silt with the remaining water. A hose or pressure washer could also be useful. 6.4 Are the tanks guaranteed? The Hercules and Carat tanks from Graf are guaranteed 15 years. 6.5 Does the pump need maintenance? The pumps in the 200 range are strong and long-lasting. They require no maintenance and, being submersible, there are no user-serviceable parts. In the case of breakdown the pump can be pulled out with its cord (the top of which is attached to the inside of the tank turret at installation) and replaced. Check with your supplier about the guarantee involved. 6.6 Is there a way of reducing pump wear? Yes. It seems un-necessary for the pump to start off pumping every time a toilet is flushed, especially because a disproportionately high amount of electricity is used when the pump starts, and because the pump, in simple installations, goes on pumping for some time after it stops supplying water. The RainDirector solves these problems. Its microprocessor-controlled roofspace header tank uses about 8 times less electricity, wears the pump less, provides water during a power cut, and has auto flush and holiday modes. We update these FAQs with real questions from clients, with the answers from our experts. If there is a topic which you would like covered please us at info@rainwaterharvesting.co.uk. Thank you 27

28 About us If you want good service and lower prices then our Rainwater Harvesting shop is the answer. We re part of the family-run Big Web Warehouse based at one of Britain s largest stock and fulfilment centres in the UK, in Peterborough. Our business survives on selling the goods you want at the lowest possible prices and delivering then to you in the shortest possible time. Our buyers scour the globe to bring you genuine savings on quality products for your garden. We stock the things you want for immediate delivery throughout the UK. Filters, decorative tanks, pumps, irrigation systems, complete kits and new ideas from manufacturers in the UK, USA, Europe and the Far East are listed. You can contact us by or phone and you re covered by our money back Satisfaction Guarantee. Did you make a dash to the garden centre last summer to find all water butts sold out, while precious new and expensive plants were shrivelling up in your garden? Or have you thought how crazy it is to wash your car with drinking quality water? Or how wasteful it is to bring water to your home from a reservoir miles away when you could provide half your water needs from your own roof? A family-owned company Rainwater Harvesting is a family owned company in the UK which brings you the best rainwater equipment from round the world, at an affordable price. We provide advice for consumers on which products to buy, and installation instructions for contractors and the more adventurous home owners. We do not provide an installation service. Our head-quarters in Peterborough is one of Britain's biggest independent storage warehouses (supplying a variety of goods not just water equipment) run by a small dedicated team. We strive to reply to every query and phone call so that you can take the best possible decision about your installation. Who knows, you might get to speak to one of the smiling faces on the Rainwater Harvesting team taken in May 2007, from left, clockwise, Marcus Bicknell (Marketing Manager and technical consultant), Adrian Lester (General Manager and Technical Head), Rob Cooper (Operations Manager and Webmaster, partly hidden, sorry Rob), Jae Lester (Fulfilment, HR and Finance), and Susie Bicknell (Research, Documentation and Customer Support). Nigel Lester (Commercial Director) missed the photo session. You can see the happy atmosphere from the picture, but we do take your interest seriously. An enquiry left with the switchboard or an to info@rainwaterharvesting.co.uk will be handled by the first of us to come free, often within minutes. 28