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Water conservation

Our ancient religious texts and epics give a good insight into the water storage andconservation systems that prevailed in those days. Over the years rising populations,

growing industrialization, and expanding agriculture have pushed up the demand for water.

Efforts have been made to collect water by building dams and reservoirs and digging wells;

some countries have also tried to recycle and desalinate (remove salts) water. Waterconservation has become the need of the day. The idea of ground water recharging by

harvesting rainwater is gaining importance in many cities.

In the forests, water seeps gently into the ground as vegetation breaks the fall. This

groundwater in turn feeds wells, lakes, and rivers. Protecting forests means protectingwater 'catchments'. In ancient India, people believed that forests were the 'mothers' of

rivers and worshipped the sources of these water bodies.

Some ancient Indian methods of water conservation

The Indus Valley Civilization, that flourished along the banks of the river Indus and other

parts of western and northern India about 5,000 years ago, had one of the most

sophisticated urban water supply and sewage systems in the world. The fact that the peoplewere well acquainted with hygiene can be seen from the covered drains running beneath thestreets of the ruins at both Mohenjodaro and Harappa. Another very good example is the

well-planned city of Dholavira, on Khadir Bet, a low plateau in the Rann in Gujarat. One ofthe oldest water harvesting systems is found about 130 km from Pune along Naneghat inthe Western Ghats. A large number of tanks were cut in the rocks to provide drinking water

to tradesmen who used to travel along this ancient trade route. Each fort in the area had its

own water harvesting and storage system in the form of rock-cut cisterns, ponds, tanks andwells that are still in use today. A large number of forts like Raigad had tanks that suppliedwater.

In ancient times, houses in parts of western Rajasthan were built so that each had a

rooftop water harvesting system. Rainwater from these rooftops was directed into

underground tanks. This system can be seen even today in all the forts, palaces andhouses of the region.

Underground baked earthen pipes and tunnels to maintain the flow of water and to

transport it to distant places, are still functional at Burhanpur in Madhya Pradesh,Golkunda and Bijapur in Karnataka, andAurangabad in Maharashtra.

Rainwater harvesting

In urban areas, the construction of houses, footpaths and roads has left little exposed earthfor water to soak in. In parts of the rural areas of India, floodwater quickly flows to the

rivers, which then dry up soon after the rains stop. If this water can be held back, it canseep into the ground and recharge the groundwater supply.

This has become a very popular method of conserving water especially in the urban areas.

Rainwater harvesting essentially means collecting rainwater on the roofs of building andstoring it underground for later use. Not only does this recharging arrest groundwater

depletion, it also raises the declining water table and can help augment water supply.


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Rainwater harvesting and artificial recharging are becoming very important issues. It is

essential to stop the decline in groundwater levels, arrest seawater ingress, i.e. prevent

seawater from moving landlord, and conserve surface water run-off during the rainy season.

Town planners and civic authority in many cities in India are introducing bylaws makingrainwater-harvesting compulsory in all new structures. No water or sewage connection

would be given if a new building did not have provisions for rainwater harvesting. Such rulesshould also be implemented in all the other cities to ensure a rise in the groundwater level.

Realizing the importance of recharging groundwater, the CGWB (Central Ground WaterBoard) is taking steps to encourage it through rainwater harvesting in the capital andelsewhere. A number of government buildings have been asked to go in for water

harvesting in Delhi and other cities of India.

All you need for a water harvesting system is rain, and a place to collect it! Typically, rain is

collected on rooftops and other surfaces, and the water is carried down to where it can be

used immediately or stored. You can direct water run-off from this surface to plants, treesor lawns or even to the aquifer.Some of the benefits of rainwater harvesting are as follows:

-

Increases water availability

Checks the declining water table

Is environmentally friendly

Improves the quality of groundwater through the dilution of fluoride, nitrate, and

salinity Prevents soil erosion and flooding especially in urban area

What is Rainwater Harvesting?

Rainwater Harvesting is a way to capture the rain water when it rains, store that waterabove ground or charge the underground and use it later. This happens naturally in open

rural areas. But in congested, over-paved metropolitan cities, we need to create methods tocapture the rainwater.

RAIN WATER HARVESTING AND ARTIFICIAL RECHARGE TO GROUND WATER

WHAT IS RAIN WATER HARVESTING :

The principle of collecting and using precipitation from a catchments surface.

An old technology is gaining popularity in a new way. Rain water harvesting is enjoying a renaissance ofsorts in the world, but it traces its history to biblical times. Extensive rain water harvesting apparatusexisted 4000 years ago in the Palestine and Greece. In ancient Rome, residences were built with

individual cisterns and paved courtyards to capture rain water to augment water from city's aqueducts. Asearly as the third millennium BC, farming communities in Baluchistan and Kutch impounded rain waterand used it for irrigation dams.

ARTIFICAL RECHARGE TO GROUND WATER :

Artificial recharge to ground water is a process by which the ground water reservoir is augmented at arate exceeding that obtaining under natural conditions or replenishment. Any man-made scheme orfacility that adds water to an aquifer may be considered to be an artificial recharge system.


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WHY RAINWATER HARVESTING:

Rainwater harvesting is essential because: -

Surface water is inadequate to meet our demand and we have to depend on ground water.

Due to rapid urbanization, infiltration of rain water into the sub-soil has decreased drastically and

recharging of ground water has diminished.

As you read this guide, seriously consider conserving water by harvesting and managing this naturalresource by artificially recharging the system. The examples covering several dozen installationssuccessfully operating in India constructed and maintained by CGWB, provide an excellent snapshot ofcurrent systems.

RAIN WATER HARVESTING TECHNIQUES:

There are two main techniques of rainwater harvesting.

Storage of rainwater on surface for future use.

Recharge to ground water.

RAIN WATER HARVESTING

AND STORAGE SYSTEMat Solar Haven

DESIGN - EQUIPMENT - COSTS - RESOURCES

Wells in our area of the desert near Tucson, Arizona average nearly 1000 feetdeep. This is also "historical" water which will never be replaced. At today'sprices, a well would cost in the neighborhood of $25,000 -- far in excess of ourbudget. Ever since we visited New Zealand almost 20 years ago, we have thoughtabout catching and storing the rain from our roof. There we found NewZealanders, rich or poor, collected the rain from their roofs and stored it in

barrels orwater tanks. Wells were the exception rather than the rule, municipalwater system almost non-existent. Why not do the same thing in our part of theSonoran Desert where rainfall averages about 12 inches per year?

Initially we used a 2500 gallon polyethylene storage tank to store the rain waterfrom the greenhouse and trailer roofs. Now the roof of the new straw bale housealso has collection gutters and pipes and a 15' above-ground swimming pool to addto our storage capacity. This is usually kept covered to keep the water from
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getting dirty and to avoid evaporation -- which is significant in the dry Arizonaclimate.

We have a standard pressure tank and a 1/2 horse power jet pump to bring waterfrom the tank(s) and maintain constant water pressure in the house.

Below Mindy is connecting the pipe from one roof collection point betweenour mobile home and the greenhouse to the poly storage tank. This system worked

very wellfor three years, but the mobile home then had to be removed

because of zoning restrictions.

Now all roof surfaces of the new straw bale house are guttered and piped in to theexisting pipes running to the storage tank from the roof of the greenhouse. Pipes

running vertically to the ground are "roof washers" -- see the section further onabout these..


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Note the rain water gushing into our tank from the catchment pipes during astorm. The green material is a synthetic pad for an evaporative cooler (threelayers) which we are using to filter out any of the more course particles of dirt orother debris which may have gotten past the roof washers. There is an additionalfilter for the finer particles located between the storage tank and the jet pump.

We have over 3000 square feet of roof surface to collect rain water between thegreenhouse and new straw bale house. TO FIGURE HOW MUCH WATER ISCOLLECTED: approximately 600 gallons of rain water is collected for every 1000square foot of collection area for one inch of rain. Thus one inch of rain producesabout 1800 gallons of water and comes close to filling the storage tank. The newabove-ground storage pool will hold about 4500 gallons.

(Fortunately our "puppy" doesn't like to swim, but he was

delighted with his new drinking bowl.)"Roof Washing System"


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Roofs get dirty, and the first water caught off the roof is likely to be dirty as well.A simple system to divert this water and discard it (or run it to the garden) ratherthan letting it go into the storage tank is used. Once the roof washer tube is full(see diagram), water from the roof is free to continue on down the gutter to thestorage tank.

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