Rain Water Harvesting

1. Saving water by re-using graywater efficiently in the garden

This aritcle is an excerpt of our Graywater Guide: from Buckets to Irrigation Systems.

With over 60 pages of detailed information, you can learn everything you need to know before deciding what is the best way for you to save water & money. The download is free and does not require registration.

In the U.S., many websites recommend saving graywater by connecting a hose to the washing machine outlet, and having this water run into a series of mulch basins in the garden (the generally accepted maximum number of mulch basins is 10).

While this feels good, it isn’t saving as much water as you may think.

As an example, consider re-using the graywater in a hot and dry location such as Tucson, Arizona.

If you put 5 gallons of water in one 4 foot diameter mulch basin every day (150 gallons per month), you have not saved 5 gallons per day
In Tucson, Arizona, that basin only needs 12 gallons for the whole of July for low to medium water-use plants & trees
The actual amount saved is 12 gallons.
The irrigation efficiency is 12/150 or 8%. The rest of the water simply drained into the subsoil, wasted.

Instead, the 5 gallons per day could be irrigating 90 square feet of garden

A family of four, easily generating 100 gallons of graywater per day, could be irrigating 1,700 square feet in Tucson

The same family could be irrigating over 2,400 square feet in San Diego, just by re-using their graywater.

In my next article, I will explain how graywater can be easily irrigated over such a large area, with or without pumps, and in a safe way approved in U.S. states that have graywater regulations.

Before even considering re-using graywater, you should ask yourself why?

The most common reasons are:
Water shortages – how can I keep my garden alive?
High utility costs – expensive watering the garden
Reducing the load on your septic system – saving money
Going green – attempting to live a sustainable life

If you don’t have a garden, re-using graywater within the house requires a treatment system. This doesn’t stack up economically if you are connected to a water supply that is relatively inexpensive.

In a non-serviced area it can make sense. Or perhaps you want / need to achieve a certain LEEDs level.

Untreated graywater irrigation systems are now very affordable and make economic sense, but you must establish the context in which it is installed.

If you don’t have a garden, or it is extremely low water use, you probably don’t need to re-use graywater.

Save water instead by installing low flow shower heads and toilets. Consider a high efficiency washing machine (although from a green perspective the carbon footprint of a new-fangled washing machine is considerably higher than the older style machines).

If you DO have a garden, think carefully about your total water usage.

The following is a great comparison showing how a “whole of property” approach should be considered:

Two people live in a San Diego house on a 7,000 square foot lot. They both have 7 minute daily showers and use the washing machine 4 times each week.

Their garden requires an average of 5,000 gallons per month for 9 months of the year.

Case 1: Using older style shower heads and washing machine, their total annual shower, laundry and garden consumption is 80,950 gallons per year.

Let’s imagine rebates were offered for a new washing machine (20 gallons per wash), and free replacement shower heads (2 gallons per minute flow), but they continue to water their garden.

Their annual consumption drops down to 59,380 gallons, a saving of 21,570 gallons.

Case 2: Let’s leave everything in place as it was (old shower heads / washing machine), but install an automatic graywater irrigation system, that is 90% efficient.

Their annual consumption drops to 35,950 gallons per year, saving 45,000 gallons per year.

How can that make sense?

Irrigating every day using graywater dripperlines is far more efficient than watering by sprinkler, hose, or reticulation system.

3,000 gallons of graywater per month will achieve a better result for the garden than 5,000 gallons per month of potable water.

I’ve raised this concept of water context very early in this series of articles because it was a very important issue in Australia. People were changing their shower heads / washing machines, but still irrigating the old way.

In most cases it is cheaper and more beneficial to re-use your graywater outside than to reduce your inside home water use.

Even in new homes, it is about the same cost (or less) to install a graywater irrigation system than a potable water irrigation system, although a make-up water connection may be required if you don’t generate quite enough graywater with low flow amenities.

Decide how sustainable you want to be.

You may only have enough graywater to support the plants and trees in the garden beds, and not the lawn.

Maybe you only have enough to water half of your garden, in which case make-up water could be used, or you decide to irrigate selected areas only.

Water conservation is all about knowing what your property needs, and applying only that amount. Don’t be tempted to run dual irrigation systems – it invariably results in overwatering. In any of the warmer states, outdoor use exceeds indoor use. Much of the problem is caused by automatic reticulation, using sprinkler heads (very inefficient) with rain sensors, rather than moisture sensors.

This aritcle is an excerpt of our Graywater Guide: from Buckets to Irrigation Systems.

With over 60 pages of detailed information, you can learn everything you need to know before deciding what is the best way for you to save water & money. The download is free and does not require registration.

by Edyta.Materka

Let’s go green with sustainable solutions

Sustainable solutions towards the environment come under various classes and categories. They include food, water, building, clothing, energy, community, transport, business, economy and ecosystem.

Community Supported Agriculture consists of a community of individuals who pledge support to a farm operation so that the farmland becomes, either legally or spiritually, the community’s farm, with the growers and consumers providing mutual support and sharing the risks and benefits of food production. Typically, members of the farm pledge in advance to cover the anticipated costs of the farm operation and farmer’s salary. In return, they receive shares in the farm’s bounty throughout the growing season, as well as satisfaction gained from reconnecting to the land and participating directly in food production. Members also share in the risks of farming, including poor harvests due to unfavorable weather or pests. By direct sales to community members, who have provided the farmer with working capital in advance, growers receive better prices for their crops, gain some financial security, and are relieved of much of the burden of marketing.

Also, sustainable solutions include greywater recycling which is obtained through waste water generated from domestic activities such as laundry, dishwashing, and bathing which can be recycled on-site for uses such as landscape irrigation and constructed wetlands. Greywater differs from water from the toilets which is designated sewage or blackwater to indicate it contains human waste. Greywater composes 50–80 percent of residential waste water generated from all of the house’s sanitation equipment (except toilets).

Bio-fuel are also form of sustainable solutions for the environment where are wide range of fuels are derived from biomass. The term covers solid biomass, liquid fuels and various biogases. Bio-fuels are gaining increased public and scientific attention, driven by factors such as oil price hikes and the need for increased energy security.

Bioethanol is an alcohol made by fermenting the sugar components of plant materials and it is made mostly from sugar and starch crops. With advanced technology being developed, cellulosic biomass, such as trees and grasses, are also used as feed stocks for ethanol production. Ethanol can be used as a fuel for vehicles in its pure form, but it is usually used as a gasoline additive to increase octane and improve vehicle emissions. Bio-ethanol is widely used in the USA and in Brazil.

Bio-fuels provided 1.8 percent of the world’s transport fuel in 2008. Investment into bio-fuels production capacity exceeded billion worldwide in 2007 and is growing.

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by Edyta.Materka

Clear Drainage – Cleaner Homes

Our home is perhaps one of our most precious possessions. But is it enough to boast of a beautifully decorated interior? Think again! The external look of our dwelling place appeals visually but what’s going on underneath the foundation is often much more important. The drainage system of any abode needs equal attention in order to provide sustainability and safety.

Drainage is the natural or artificial removal of surface and sub-surface water from an area.

A smart drainage solution is mandatory to dissipate surplus water both in farming lands and in residential areas. Untreated excess water abets the chances of erosion of the foundation, making the structure of your home unstable. On the other hand agricultural soil needs drainage to enhance production or to manage water supplies.

An underground drainage system comprises of pipes and storage tanks made from perforated wall modules to form the desired size and configuration. They are wrapped in a water permeable geotextile. The system is preferably buried in clean sand, whereby rainwater and runoff water is directed to flow through the water permeable geotextile.

Drainage can be either natural or artificial. Many areas have some natural drainage which means that excess water flows from the farmers’ fields to swamps or to lakes and rivers. Natural drainage, however, is often inadequate and artificial or man-made drainage is required.

Types of artificial drainage:

Surface drainage is the process of removal of excess water from the surface of the land. This is normally accomplished by shallow ditches which are also called open drains. The shallow ditches discharge into larger and deeper collector drains. In order to facilitate the flow of excess water towards the drains, the field is given an artificial slope by means of land grading.

Subsurface drainage is the removal of water from the root zone. It is accomplished by deep open drains or buried pipe drains. Excess water from the root zone flows into the deep open drains. The disadvantage of this type of subsurface drainage is that it makes the use of machinery difficult. Pipe drains are buried pipes with openings through which the soil water can enter. The pipes convey the water to a collector drain.

Drainage system that lies beneath your home works hard at all time to keep your abode prim and proper. Not only does it have to process water waste that is created by bathing and washing dishes, but it also handles sewage waste and outside water that is draining off your home. This is a tough set of responsibilities for the residential underground drainage system to handle so you might want to think proactively about keeping this system in working order.

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by Edyta.Materka

Using A Gravity Fed Drip Irrigation System

A drip irrigation system is the most efficient way to water plants in a flower or vegetable garden. Connecting a drip system to a rain barrel or storage tank will maximize your water conservation efforts. This type of watering system is known as gravity fed drip irrigation.

One advantage to using rainwater diverted into a storage container is that it is pure and untreated. This water is much better for your plants because it contains none of the chemicals like fluoride or chlorine that is typically found in treated city water.

When deciding on a storage tank or rain barrel, be sure to check the outlet at the bottom of the tank. Ideally you should have a ¾ inch male hose thread like you would find on a standard spigot. If it has a different outlet you may need to purchase adaptors to allow you to connect a drip irrigation system.

With all drip irrigation systems, a minimum pressure is needed in order for it to properly operate. To gain pressure in a gravity fed system the water source needs to be elevated. The rule of thumb is that for every 2.3 feet of elevation the pressure of the system will increase by 1 pound. A water tank that is 2.3 feet tall will have 1 pound of pressure when it is completely full. However when the tank is half empty the pressure will come down to half of a pound of pressure. The same water tank elevated 5 feet in the air will have around 3 pounds of pressure when completely full.

Consider emitters and emitter tubing that will work at extremely low pressures when putting together a gravity fed system. The take apart emitters from Jain Irrigation work very well. Quarter inch soaker dripline and T-Tape are perfect for watering row crops from a rain barrel. Most watering timers available for drip irrigation systems require around ten pounds of pressure to operate which most likely will not work in this situation. However the latest technology has produced a few timers that can operate without any pressure at all.

Keep in mind that the closer the distance between your tank and garden the better. Also note that the emitters at the beginning of the drip irrigation system will most likely emit more water than emitters towards the end of the system.

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by Edyta.Materka

Use Less Electricity With A Smart Header Tank Rainwater System

Nowadays people are under pressure to reduce their mains water consumption. Simply by using rainwater off our own roofs, we can reduce our use of mains water by 50% which will enable us to reduce our total carbon footprint.

However, most rainwater systems need a pump to get the water to where it is needed. Also, the pump must be powerful and requires electricity. This way does not help the carbon footprint and also the running cost has to be taken into consideration when fitting a rainwater system. Typical “direct feed” rainwater systems have a pressure sensitive pump which maintains pressure on the rainwater pipes to toilets, washing machines and any non-drinking-water tap. Every time an appliance is in use, the pump switches itself on. Furthermore, as pressure in the pipe run drops, the pump will start up again even when there has been no demand on the water supply. The pump, therefore, “hunts”, i.e. it automatically turns itself off and on as needed throughout the day and night. So because the pump starting up draws a peak surge in power, electricity use is unnecessarily high. Additionally, this exertion increases the wear on the motor, seals and pump bearings.

Using a gravity feed system in conjunction with a specially-designed header tank solves this issue.

Energy-saving rainwater systems use a smart rainwater header tank. The main storage tank pump feeds rainwater up to the header tank. This way the appliances are fed by gravity. In smart header tanks, such as the Rain Director, the electronic sensor will start the pump only when the tank is completely empty. A 91 litre header tank will last for 12 toilet flushes, and a clothes washing machine cycle, i.e. more or less an average family’s daily use. It also takes just under two minutes for the pump to refill the header tank. The pump would only cycle one time per day in your average home.

About ten times less power will be used. Presuming one washing machine use and 12 WC flushes each day, with a direct-supply pump system energy use is @ 1.5 kilowatt-hours (the same as using a 1000 watt electric fire for an hour and a half each day). With a smart header tank system, it is only 0.15 kwh per day. So with 1000 kwh costing around

by Edyta.Materka

Harvesting Rainwater to Drought Proof your Garden

Harvesting Rainwater to drought proof your garden seems like a contradiction in terms as it implies the use of water to save water. After all the reason that you drought proof your garden in the first place is to decrease your water usage so using water to save water in some respects may not seem to make sense.

Having said that though, that’s exactly what I’m doing. I use water to save water and in particular I use rainwater. One of the things that I’ve noticed in the hotter months is that hot winds can dry out your garden a lot quicker than the sun just on its own. The way I’ve gone about solving this problem in my garden is to grow a hedge as a windbreak along the northern (for the southern hemisphere) boundary of my backyard.

The first important thing to consider in doing this is to select the correct plants to start off with. I’ve used Callistemon Salignus, aka the Willow Bottlebrush and here are the reasons why.

Firstly it will not grow too large if you restrict the amount of water you give it after it’s achieved the desired height to block the wind. That way it won’t become a problem in a small suburban garden.

Secondly it is also fairly drought tolerant. Last summer my hedge of Callistemon Salignus withstood some fairly strong, hot, drying winds without any extra water so it’s an ideal tree to use as a windbreak.

Thirdly and most importantly they can withstand water logging. This means that during winter and spring when you may have excess water in your rainwater tank you can direct it straight to your hedge of Callistemon Salignus. I direct rainwater from the overflow of my rainwater tank straight to my hedge so when my tank is full the excess rainwater doesn’t go down into the stormwater, but into the soil where it is stored for when the trees need it during spring and summer. This means that the trees get rainwater from the sky and the overflow from my rainwater tank at the same time.

This fits with what most gardeners know. Less frequent deep watering is much better that more frequent shallow watering.

Another great feature about Callistemon Salignus is that it is reasonably quick growing and also very hardy. Both of these qualities are very important when growing a hedge. How many times have you seen hedges that have been grown with plants that look great but aren’t necessarily very hardy. Quite often these types of hedges always seem to have one or two plants in them that have died. It really can detract from your hedge. Also most hedges are normally grown for a reason such as privacy or as in this case a windbreak. Therefore, being able to grow fast and establish quickly is a definite requirement. Callistemon Salignus will certainly grow fast but what I’ve discovered is that if you give them lots of water not only during winter and spring but also during summer, when rainwater is scarcer, they will grow even faster.

This means that the more I use my stored rainwater to increase the growth of my windbreak then the faster it will protect the rest of my garden from hot drying winds during summer. Once your drought tolerant windbreak is then established and at a height where it is shielding those hot summer winds you can then back off on the watering and start saving on water in other parts of your garden such as a lawn.

So there you have it, the use of water when used correctly can save you water in the garden in the long run and of course there is no better water to use than rainwater. So for me there is no better way than harvesting rainwater, so I can drought proof my garden.

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by Edyta.Materka

Does Harvesting Rainwater really help the Environment?

In some parts of the world there is still a certain amount of skepticism about the merits of harvesting rainwater and if it is in fact beneficial to the environment. This may possibly be because harvesting rainwater in rainwater tanks is still a new concept, especially in some modern urban areas where householders are very used to just turning on the tap to water their garden or fill their swimming pools.

I remember when growing up, rainwater tanks, water issues and drought were very rarely talked about. We had all the water we needed. I remember we’d use water for hosing down concrete paths and driveways. We’d pour as much water as we’d liked onto our lawns over summer and as kids we’d spray each other with the garden hose for hours.

And of course all of this water came from our local water storages. These water storages were always full of water, as every winter it rained and filled them up. Then during the summer we’d do our best to try and empty them again but the levels never really seemed to get low.

These days though it’s a different story. South Eastern Australia has now been in drought since 1997. As a consequence most of the water storages, lakes, dams and reservoirs are now perilously low. This winter in 2009 we have received average rainfall which is the first time since 2000. Unfortunately all this has done is slow the decline of Melbourne’s water storages which are now at an all time low of 29%.

To fill these water storages with water is going to take a lot of rain over many years. Unfortunately for South Eastern Australia, this upcoming summer is tipped to be hotter than normal. The likelihood of bushfires of the scale of Black Saturday, during February this year, are high. Low rainfall is also forecast so the chance of ever getting enough rain to fill our storages seems low. Unfortunately though, Australia is not alone.

There are now many parts the USA, India, Asia, Africa, Europe and many other places that are also experiencing lower than average rainfall and low water levels in their water storages.

As a gardener I’ve watched the climate change over the last 13 years and whether or not this cycle of dry weather continues is anyone’s guess. In the meantime though, I’ve installed rainwater tanks for harvesting rainwater for my garden. I have a green lawn in my backyard during summer and I can wash my car or clean my paths whenever I want to. The most amazing thing that I’ve discovered is that even in a climate where you only get around 300mm (12 inches) of rainfall per year I can still harvest lots of rainwater. It all has to do with how much of your roof you can harvest rainwater from.

Underground rainwater tanks are very good at harvesting rainwater from all of your roof area. Unfortunately, these are not always viable for some houses. They can be expensive to install and for existing houses they may not be an option. Above ground rainwater tanks are cheaper and easier to install but it can be difficult to harvest rainwater from all of your roof area. Most people don’t really want a rainwater tank at the base of every downpipe or downspout on their house.

These days it is now possible to harvest rainwater from all of your roof area and direct it to above ground rainwater tanks without having to place a rainwater tank at the base of every downpipe. This means that above ground rainwater tanks are now a viable less inexpensive way of harvesting rainwater from all of your roof area. As a consequence large volumes of rainwater can be harvested from your roof even during a drought.

The other important advantage of being able to harvest rainwater from all of your roof area is that during summer when you’re not getting very much rain and you are using lots of water, you can really maximise the amount of rainwater you can harvest. That means that if you only get a little bit of rain you can still harvest lots of rainwater.

Rainwater tanks are now a viable alternative to using water from already stressed water storages. This can only be good for the environment and the extra water will also allow your garden to flourish which will be good for the environment as well. Harvesting rainwater and storing it in rainwater tanks is just a beginning but the more people that harvest rainwater, the bigger the impact it will have and then everyone can benefit from harvesting more rainwater.