Archive for June, 2010

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Earth homes and how water can be saved in them

June 15, 2010

http://www.youtube.com/watch?v=omFxf-qRvqM&feature=related

Preliminary research suggests that earth homes use about 270 litres of water per square foot of construction, about 1/4th of conventional brick mortar and RCC construction. Embodied water is thus much less in earth buildings.

Also these building harvest rainwater, recycle waste-water and have very little water footprint in their life cycle.

A good reason to build with earth.

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Water wise on Leh town

June 13, 2010

WATER WISE

Managing water supply

S. VISHWANATH

When tourists arrive in large numbers and consume water excessively…


TRADITIONAL WISDOM: In Leh town of Ladakh, surface water which flowed when the glaciers melted during summers formed natural ponds called ‘zing’

It can get cold in Leh. Temperatures of minus 20 C are not unheard of. Pipes full of water will simply burst in winter. The town is in many ways typical of small town India and in many ways it is not. Weather-wise, it most definitely is not. The population of the town is about 20,000 but take the military presence here and the tourists who throng the place come June and the population can soar to 60,000-70,000. Managing water and sanitation for a tourist population which demands hot water, long showers and a flush toilet becomes a challenge.

Traditionally, the town managed with surface water which flowed with the glacier melt during summers and collected in small ponds called ‘zings’. The toilet was also a dry composting toilet. No water was required for flushing. You just did your job in a small chamber and covered it with earth.

At the end of the year you collected it and took it to your fields along with farmyard manure and this became the fertiliser for the crops you grew. A bath happened once in a week in summer and maybe once a month in winter. Water demand was low and estimated at about 60 litres per person per day.

But came the tourists and things dramatically changed. Aggressive promotion of the place and its surroundings by the Tourism Department has seen a steady rise in both foreign and domestic tourists. Domestic tourists for the first time overtook the number of foreign tourists arriving in Leh. Farmlands are converting into guest homes and hotels. Borewells are being dug all over the place. First to depths of 100 feet below ground level and now to 200 feet.

Water shortage

In the absence of an underground drainage system septic tanks in every resort discharge the effluent into the ground. The tourist expects the same comfort as at home and hot showers and flush toilets result in 130 to 150 litres of water per person per day.

The end result is water shortage in many places and dependence to the extent of 80 per cent of the town’s needs on groundwater.

Several initiatives are emerging to make water sustainable for the town. A NGO is working towards building a large reservoir upstream using local knowledge and skills. This will provide sufficient water to the farmers all the way downstream in the Leh valley.

Another NGO with the redoubtable Chawang Norphel, the glacier man of Ladakh, is trying to built artificial glaciers to hold water in winter and release it gradually in summer. LEDEG, a vey old and experienced NGO, is working to understand groundwater better and take steps to involve the community and institutions in managing groundwater .

Huge task

The government too has drawn up a large project to manage solid waste and liquid waste better. It does a herculean job in pumping water from borewells close to the Indus river up 300 metres in three stages. When electricity is not available diesel pumps are used to lift the water for distribution in the town.

The tourist season is short and lasts for four months. Leh’s economic engine now runs on tourism and the army. Responsible tourism is being encouraged by many groups such as the WWF, especially with its green hiker programme. Small shops refill water bottles, thus preventing disposal of plastic bottles, and green organic products abound.

Water wisdom lies in understanding local issues emerging around water and finding local solutions. Building the right institutions too is crucial. Institutions which have the knowledge and concern, responsibility and accountability, work with local knowledge and wisdom but bring in outside expertise when required.

Working in hostile conditions such as Leh and finding solutions is extremely rewarding. Let us hope the partnership of citizens, NGOs and institutions find a way for sustainable water management in Leh.

zenrainman@gmail.com

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Managing bore-wells in urban areas

June 6, 2010

WATER WISE

The trouble with borewells

S. VISWANATH

In the long run they will succeed only in depleting the water-table


dire need: A borewell being drilled

A recent session of the Bangalore Mahanagara Palike resulted in the promise of four borewells per ward being dug to overcome the water shortage facing the city. That would add up to around 800 borewells , not really much considering that there are over 110,000 borewells listed by the BWSSB wherein it collects Rs. 50 per month as sanitary cess. Another ‘guesstimate’ would have it that Bangalore has at least 200,000 borewells pumping out anywhere between 100 million litres and 400 million litres of water per day from the aquifer. That is a phenomenally high number in an absent legal or institutional framework for managing groundwater.

Borewell rigs and drillers are having a field day. They work 24 hours a day, catching sleep on the site itself by turns. No log sheet of the drilling is left and the quality of work suffers too but they are only responding to a desperate city drilling away for water.

The new borewells as demanded by the corporators, if they strike water, will of course solve the problem of the citizens for the immediate future. In the long term they will however succeed only in further depleting the water table. The good news is that the water table is actually rising in the city centre.

The bad news is it is the leaking sewage and waste water which is making the water table rise. This ensures that over 60 per cent of the borewells tested have reported contamination by nitrate, especially in the three major valleys of the city — Koramangala-Challaghatta valley, Vrishbhavati valley and Hebbal valley. The new borewells drilled will, of course, have to be tested for water quality and many are likely to be found unfit for drinking. Will the problem of water shortage be solved then?

Demand management

A borewell linked to a hand pump has a built-in demand management. You can pump out only so much water and that depends on the physical capability of the persons pumping. On the other hand, an energised borewell needs a switch to be turned on and water is sucked out at the rate of litres per hour. Unless a borewell is connected with a water meter, no information can be available as to how much water is being pumped out from it and in general from the overall aquifer. All borewells must have water meters in Bangalore and an institution, preferably the BWSSB, must take monthly reading to determine the withdrawal of groundwater.

In its own borewells the BWSSB must have water meters and keep a track of the water quality and quantity and the depth of the water table. This will give invaluable feedback for the correct management of groundwater. While the BWSSB is recruiting new staff, a hydro-geological/groundwater cell must be set up and staffed adequately.

Borewells with non-potable water must be marked and people warned from drinking the water. Alternative arrangements for potable supply must be made in these localities.

Linking water supply from borewells to the Cauvery waters must be considered. This will reduce the nitrates and high salinity level as well as enable treatment of all waters to reach potability limits.

Groundwater in urban areas is a complex matter. While natural rates of recharge can vary between six and 10 per cent, because of urban crusting, rates of recharge become much less in cities. Polluted waters also end up in tanks and further harm the groundwater. Septic tanks and pit latrines add their bits to the contamination.

A good sewage system and a well-functioning solid waste collection system is a must to maintain quality of both surface water and groundwater.

Focusing on a holistic approach to water in a city is the need of the day and in this lies water wisdom.

http://www.rainwaterclub.org

zenrainman@gmail.com

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