Reaching out
My river, my management


Andhra farmers try their hand at water management


CSE continues to educate the educators


MEASTro knows it all!
Cavern construction
What the world thinks of water


Chennai branch of NWHN: full steam ahead






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Vol. 1                                    No. 3                              August 1999

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MAESTro knows it all!

United Nations Environment Programme’s (UNEP) International Environmental Technology Centre (IETC), based in Japan, has created a searchable electronic database on Environmentally Sound Technologies (EST) called maESTro.

maESTro is an information tool which contains data on a wide range of environmentally sound technologies, institutions and information sources related to water pollution, environmental management, human settlements, hazardous substances, solid wastes, wastewater, water augmentation and many more. EST contributors, individual users, organizations and institutions regularly update this information.

This data is distributed free of charge on floppy diskettes, CD-ROMs and in printed hard copy formats. This information is also accessible on the worldwide web at

maESTro is free of charge and promotes interactive global networking.

Cavern construction:
The Water Harvesting Company of Stockholm, Sweden, has hit upon a novel technology to store rainwater ( huge underground caverns. An environmentally sound technique, it can greatly increase the volume of freshwater stored underground.
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This technology is based upon the recognition that rarely is water shortage a question of inadequate precipitation, but a problem of limited infiltration and storage space.

There are three major components to the Swedish technology: the collection area, the conveyance system and the storage facility. The collection area can cover the entire landscape, by taking advantage of the natural topography. The conveyance system is natural: the forces of gravity ensure that water enters the geological structure surrounding the cavern only to find its way to the lowest point in the hydraulic system. This gravity system can be improved by drilling holes between the cavern and neighbouring fissures. Storage depends on the size of the cavern, which is a large porous fissure that becomes part of the geological structure.

The technology is fairly cheap and initial investments range from Rs. 2000 to Rs. 4000 ($50 - $100) per cubic metre of created cavern. Thus water that would be otherwise lost to flash floods and evaporation can be safely collected and stored underground.

What the world thinks of water — and how to manage it.
Water is no longer being viewed for what it is - just water. A natural resource, it is increasingly being viewed as a commodity that has to be used rationally, priced appropriately, managed, banked, traded, sources recharged and reused as much as possible, wherever possible.

The US: Groundwater recharge makes sense - in addition to replenishment, evaporation losses are minimal, the chances of secondary contamination reduced, there are reduced alga blooms and reduced pumping costs. Moreover, recharge also reduces the gradual subsidence of land due to water extraction."Aquifer storage and recovery systems allow for the storage of excess surface water during periods of high surface water flow and its subequent recovery during periods of low surface flows and high demands,"says Peter Fox of Arizona State University, Arizona. Fox is an ardent advocate of aquifer recharge.

‘Groundwater recharge has to be an integral part of water resource planning in urban areas now, given the fact that traditional means to meet growing water demand in urban areas requires the exploitation of surface and subsurface resources to the maximun extent possible, adds Fox.

The most common way of aquifer recharge is the use of recharge basins where water is allowed to collect on large pieces of land that allow the stored water to percolate through. This however is land intensive. Technologies are now available where the water can be recharged into an aquifer by injecting into wells that are dug above an aquifer and the water percolates into it or through a direct injection well that ends in an aquifer.

Arizona is moving towards a groundwater banking system. Entities that recharge groundwater receive credit for the amount of groundwater they are recharging, which they can then sell to groundwater users. The Groundwater Management Act (GMA) has established a goal of zero groundwater mining by the Year2025. The GMA has established a system of ground water management systems combined with a system of penalties and incentives. Groundwater users are penalised on an escalating scale for withdrawing groundwater without recharging it. The penalties force the groundwater user to either recharge groundwater or purchase groundwater from a ground water supplier.

Mexico: In Monterrey, Mexico, ground and surface water resources are in short supply, unable to meet the demands of heavy industry manufacturing plants. To meet their demands, industries on their own, or in a consortium have constructed wastewater treatment plants that provide treated effluent for industrial process water.

Wastewater is purchased from the city, pumped from the sewer into a treatment plant and the treated water distributed to industries. While individual industry owners reuse the treated water on their own plant property, in places where there is a consortium, the treated water is distributed through a water distribution network.

With the construction of 3 large wastewater treatment plants in the city by the Monterrey Water and Wastewater Authority, virtually all the wastewater from the city is treated and reused either directly for non potable use or indirectly for potable water use throughout the city.

Harnessing the impossible:
It is possible to harness runoffs from very large wadis or dry river beds. Using low technology. Too erratic to warrant high engineering investment, this technology makes use of the construction of dykes all along the seasonal stream, so that each one will detain only a small part of the flood: the rest of the water will flow past and be diverted to the next dyke and so on. These dykes would allow the percolation of large amounts of water, enriching any existing underground storage.

Engineers fear the unpredictable and often leave large, seasonal and unpredictable streams with catchment areas of 100,000 hactares or more untouched. The excuse: lack of ‘adequate’ hydrological data, large volumes of water and sediment and the high cost that accompanies the harnessing of water under these conditions. This is where size comes in. It is possible to harness water on a small scale, on large streams. All in a modular manner, making use of only a small portion of the flood at a time.

The main specification is that the width of the spillway equal the narrowest part of the wadi. The next step is to build a series of L- shaped ponding dykes, one leg being perpendicular to the line of flow and connecting with the bank and the other parallel to the line of flow, adjacent to the spillway channel.. The length of the dyke is as long as is needed to leave an adequate channel for the spillway. The height of the dyke should be sufficient to hold 2 m head of water, allow for a flow of 1 m deep in the spillway with 1 m freeboard- a total height of 4 m. The longitudinal wing extends upstream upto a point 2m higher than the base line of the perpendicular dyke.

To divert water from the spillway channel into the dyke, a diversion ditch is constructed which then allows for water to fill in the pond. Once filled excess water drains back into the spillway channel leaving a 2 m water column of water behind to percolate into the ground. If a series of such dykes are constructed, each one will detain only a small part of the flood water and the rest will flow past and be diverted into the next dyke and so on. In this way, it is possible to capture medium sized floods completely.

Germany: Germany appears to have realised the potential of harvesting rainwater. "Rainwater utilisation is now recognised as an advanced, ecologically and permanently safe operating system,"says Klaus Konig from Professional Association for Water Recycling and rainwater catchment systems, a NGO from Uberlingen, Germany. In Germany, in the nineties, several thousand rainwater utilisation installations have been installed. To ensure the quality of rainwater collected and that the potable water system is protected and secure from possible contamination by individual installations, there now exist legally binding regulations within the German potable legislation. For instance, no connection may be made between the rainwater system and the potable water system.

In The Berlin Communal Dwelling Rainwater Utilisation Project, the rainwater from all the roof areas is disposed off through the public rainwater sewers of the Berlin Water Companies, into separate sewers. Along with the outflow from streets, parking spaces and pathways, it is then tranferred into a 160 cubic metres capacity cistern. After simple treatment, the water is used for toilet flushing and gardening.

In Germany, hectic efforts are on to develop an efficient ceramic toilet that uses only 3 litres of flushing water. All rooms in the Arabella hotel in Berlin are equipped with water saving toilet system, which has a split operation panel. For flushing faeces, 4litres are used, while for flushing urine, the quantity of water is reduced to 2.5 litres.

Singapore: In Singapore, the Public Utilities Board (PUB) is the national water authority. It has proven to be an efficient organisation providing reliable potable water at the most ecoomical cost. Programmes of water literacy, people’s participation and reliable water meters that are regularly monitored coupled with a responsive group of public engineers has been the formula adopted. Plumbers are given licenses to ensure good quality of plumbing work. All water fittings and pipes are inspected by the PUB before installation. All accounts are metered, even temporary ones at worksites. These metres are checked monthly. The billing is computerised and any fluctuations are automatically detected by the computer. Customers are advised to check for leaks if the readings are abnormally high. They are also encouraged to take their own readings. Replacement of mains have reduced leakage problems and improved water quality.

Water demand management included the implementation of water conservation measures, tariff restructuring, legislative measures and educating the public.

Israel: The million dollar question is: how does Israel survive with less than 300 cubic metres of water per capita per year when international organisations define arid countries with less than 1000 cubic metres per capita per year as highly stressed countries where water becomes a severe constraint to growth.

"The answer lies in water demand management," reveals S Arlosoroff, a retired World Bank Water expert. The management has succeeded- Israel now has a GDP of $ 16000 per capita per year, it produces most of its food, with the exception of grains, it even exports agricultural produce, supports the water requirements of industry and the people are able to maintain a high standard of living- all with a very limited supply of fresh water.

The management package includes a cocktail of legislative, institutional, economic and technological measures, focussing on water demand management increased efficiency use of water in agriculture, reuse of most of treated sewage effluents as well as integrated use of surface and ground water resources. "By the year 2020, Israel will be reusing 70-75 % of treated effluents,"predicts Arlosoroff.

Source: All inputs below are based on the 3 day symposium on ‘Efficient Water Use in Urban Areas- innovative ways of finding water in cities,’ held in Japan between 8-10 June, 1999. The symposium was organised by United Nations Environment Programme - International Environmental Technology Centre, Kobe, Japan