Water, Habitat and Sustainability--Towards the wise management of water
Dr. (Ms.) Mahua Mukherjee
Lecturer, Dept. of Architecture & Planning
Indian Institute of Technology, Roorkee
Roorkee, INDIA -247 667
The importance of water to the sustainable habitat is enormous. Water, invariably plays a vital role in this continuity. The concept of sustainable habitat has a direct analogy with flowing river. Human being selected sites for settlement with easy access to water. Water is being used for drinking, agriculture, potteries, raising live stocks etc. The water has a balanced hydrological cycle of water vapour, water and ice. Water is retained on sea, river, lakes etc. which act as a major heat sink and dominate the micro-climatic features; it percolates and stored as ground water. Extreme human is affecting the future of the existing and new settlements. Acute scarcity of water is common feature in important cities like Delhi, Manila etc. The water has influenced the religion and culture of societies since ages. In the present paper the author to address the urgent need to avoid our future generations’ risky future. The mistakes are reaching to the limit of irreparable losses and new input fails bring positive changes in the settlement and its environment. To survive society has to achieve sustainability or the nature’s balance would wipe the human being from the scenes of evolution. The model SusTLE (Sustainable Total Living Environment) developed by the author would be put to use for qualitative discussion.
INTRODUCTION
Through ages the life has been evolved in different form and natural selection has retained the best for future. Water plays a vital role in life on earth. The importance of water to the sustainable habitat can be best emphasized by acknowledging the fact that it is the prime mover for the existence of living being on our planet Earth. Water is one of the resources, which demand intelligent management. With time the increasing intensity in Land use creating back lash to the natural water cycle (See Figure 1). Urbanisation is so rapid phenomena now, that United Nations [1] has reported that the rural population will be minority by the year of 2007.
The urban people consume high proportions of water for their daily usage in comparison to their rural counterpart. Due to the pressure of urbanization land use pattern is being changed rapidly. Provision to store water like pond, lake, even the rivers is being pushed to the threshold of existence. Rapid increase of virtually water-proofed surfaces in urban areas and highways, are speeding the process of run-off and resulting in low and slow recharging of ground water. The Industrial sector is another major consumer of water. Ground water level in urban areas isdepleting at an alarming rate. The rising demand from rapid urbanisation are causing excessive withdrawal, thus resulting depletion of aquifers and lowering of water tables. Even before the summer start urban areas reels under acute shortage of water.
Figure 1. Use of water in different human settlement
The paper explores the attempt made by different urban authorities to cope up with water problem. A comprehensive study related to this issue made by the author enables her to understand the relation between quality of living and sustenance, with water management. To quantify the problem the author has used the context of India and Indian cities in this present paper. The model SusTLE has been introduced to control the water crisis in today’s cities.
WATER & SETTLEMENT
Present day human intervention in the hydraulic cycle (as discussed in section SOURCE OF WATER) proves to surpass the limit of endurance of nature- encroachment of reserve habitats, deforestation, filling up the wetlands/ water bodies to give space for new constructions are affecting the future of the existing settlements as well as the new ones. Deforestation is causing more runoff of rainwater with erosion and thus less moisture conservation and less ground recharging.Acute scarcity of water is common feature in important cities like Delhi, Manila etc. Example of Fatehpur Sikri in Indiais an historical lesson. It conveys the warning: even if a settlement excels otherwise, absence of sufficient water can make it deserted quickly.
The characteristics of urban people has been correctly delineated by Lewis Mumford in his Natural History of Urbanization, 1972, as –“…another tendency, distinguishes the city from the village- a tendency to loosen the bonds that connect its inhabitants with nature & to transform, eliminate or replace its earthbound aspects, covering the natural site with an artificial environment that enhances the dominance of man and encourages an illusion of complete independence from nature”.
The stages in water cycle in short can be described as evaporation from the sea, rain/snow fall, transportation over ground and flow back to the sea. Evaporation and percolation occurs during the process of water transfer through rivers or so. The terrestrial life is benefited if the time taken by water is lengthened from the rain fall stage to flow back to the sea. The living being gets hold of water in different form like lake or river, the subsoil ground also gets scope to be recharged with water. The vegetation cover of natural soil helped to retain the water and used to provide protection against soil erosion. Water drawn from the river needs purification. But the natural method of purification i.e. percolation through different soil strata is totally neglected in the process of industrialization. The balance between the demand and supply of water in larger urban spectrum is greatly disturbed due to short-sighted management policies.
Source of water
The water has a balanced hydrological cycle of water vapour (evaporation), water (condensation in the form of rain water, dew etc.) and ice (glaciers or snow). Water is retained on surface in sea, river, lakes etc. which act as a major heat sink and dominate the micro-climatic features; it percolates and stored as sub-grade ground water. Water is a principal climatic element which dictates the appropriate building material and form of settlement as a whole and as individual elements like houses. The alternatives of water sources are primarily:
a)Ground water in the form of tube/ bore-well,
b)Surface water in the form of river, pond, lake, etc.
c)Rainfall
d)Recycling of waste water
SUSTAINABILITY
The concept of sustainable habitat has a direct analogy with flowing river. Throughout its journey it interacts with boulders, forests, habitats, including human habitats ranging from hamlets to metropolitan cities, agricultural fields, industrial estates etc. It has vital force to change or accept change and assimilate that change into itself through new courses of action. Habitat does not consider shelters singularly. It can be defined as group of houses sharing services and networks with the background of healthy environment. Water is very much part of the habitat being a basic aggregate of environment.
Human being learnt and took the cue from other living beings that the other name of life is water and selected sites accordingly to inhabit. In the history of settlements it had been evident that water played a crucial role for the success of any settlement. Water is being used for drinking, agriculture, potteries, raising live stocks etc. It became an important mode of transportation. Even when it brings disasters with flooding, the land becomes fertile again. The flourishing trades in Greece and Rome gave them the status to be regarded as world power due to their success as naval force and sea-commerce. In middle ages, the European countries made voyages to unknown places; and trader became the colonial rulers and credit goes to controlling power of sea routes primarily.
The water is also influenced the religion and culture of societies for ancient days. Starting from baptism in Christianity to the Hindus’ rituals is directly related to water and they are examples showing how deeply the water influences the religion. The sacredness of water is part and parcel of religion. Similarly it can be said that the influence of water in culture is also conclusive. Wherever the society has water in any form, be it be river or lake, it is part of their lives through songs, dances, paintings, folk drama etc.
Water used to be managed wisely since time immemorial. The settlements depended heavily on the primary source of water i.e. rainwater. It is only recently that people extracted water from secondary sources like pond, river or sub-surface reservoir, without being serious about storing or recharging the ground with rainwater. Unplanned, uncontrolled extraction of ground water has disturbed the hydrological balance, and deterioration in quality of water. Water shortage in an urban area is not due to scanty rainfall. As a result of short-sighted faulty management system, they face this problem of water scarcity as shown in Table1. Cherrapunji gets highest rainfall in the world (11000mm annually). In absence of any serious effort to store or harvest that water it faces severe water problem in summers.
Recycling of used /waste water,as they are laden with chemicals or pathogens, needs treatment. There is several successful waste water recycling projects in urban areas. In Kolkata, East-Kolkata Wetland is such an example. It serves the city not only in handling the waste water and sewage treatment, also supplies fresh vegetables, flowers, fishes to the city market on daily basis. But natural treatment demands large low-lying marshy wetland which is becoming scarcer in and around any urban area. Indian cities are now exploring the option of rainwater harvesting to solve the water crisis.
The Pune Municipal Corporation (PMC), along with United States Environment Resource Centre, is planning rainwater harvesting. The pilot project would cover 10% of city’s population with water harvesting solution. The PMC is giving a thought to make it compulsory in its development control rules for new constructions to either have rooftop harvesting or to make provision for recharging groundwater.
Table 1. Rainfall Distribution at various Urban Centres in India
Source: Paul,.[3]
City / Average Annual rainfall (mm) / Surplus/Deficit in waterMahabaleswar / 6635 / Deficit
Trivandum / 1696 / Shortage
Chennai / 1268 / Acute shortage
Bhopal / 1180 / Shortage
Bangalore / 900 / Acute shortage
Hyderabad / 747 / Acute shortage
Ahmedabad / 742 / Acute shortage
Delhi / 666 / Shortage
Ajmer / 527 / Shortage
Jodhpur / 361 / Shortage
Dwarka / 353 / Acute shortage
Bhuj / 345 / Acute shortage
Barmer / 300 / Acute shortage
Bikaner / 291 / Acute shortage
WATER AUDIT
Rainfall is termed as primary source of water and its contribution to the world’s water supply is in Table 2.India is bestowed with many rivers (14 major, 44 medium and 55 minor rivers). Lengthwise they cover 45000 Km. Together the rivers contribute around 80% of India’s total water. Indus, Brahmaputra and Ganges are the three International Rivers. The Table 3 presents some logistics about Indian water. In India which experience very good rainfall options for rain water harvesting can be feasible solution. India’s average rainfall data is 1170mm in comparison to global average of 800mm [2].
Table 2. Contribution of rainfall to world’s water supply
Data Source: Gopinath, K.R[4]
Sl.no / Description / %1 / Water in seas and oceans / 97.2
2 / Water in glaciers & icecaps / 2.14
3 / Underground water / 0.16
4 / Surface water / 0.009
5 / Soil moisture / 0.005
The increasing urban population is increasing the pressure on the water service. The piped water has not only introduced more consumption of water, in a process the wastage of water during carriage through leakage is also alarmingly high. As a result of all these issues the water distributed at the users’ end is declining every season as shown in Table 4.
Table 3. Annual water data for India
Data Source: Chadha & Kapoor [5]
Description / Unit (billion cu. meter-BCM)1 / Average annual precipitation (rain & snow fall) / 4000
2 / Runoff from other countries / 200
3 (a) / Average annual water resource (in river basins) / 1869
(b) / Utilizable annual water resource
(surface water + ground water) / 1086
(690 + 396)
(c) / Evaporation, percolation and waste to the sea / 783
Table 4. Decline in per capita water availability in Indian cities
City / Water availability in LPCD1994-95 / 1997-98 / 2003-04
Delhi / 341 / 257 / 240
Mumbai / 192 / 135
Kolkata / 200
Chennai / 90 / 70
Bangalore / 120
Pune / 250 / 200
SUSTLE
The problem of water shortage in urban areas needs to be addressed with water management approach. Like any other resources it needs community’s participation in making decision to the methodology to be followed and sharing of it. With this aim the author would like to extend the scope of Sustainable Total Living Environment (SusTLE) Model which she had developed during her doctoral research work[7]. The model integrates the issue of community participation with logical allocation of resources to ensure a sustainable development. It accommodates the idea on quality of living rather than standardization (e.g. in Delhi, availability of water to every person in the settlement to be ensured rather than providing excess amount in some special zone and no water in others), democratic decision making process rather than bureaucratic one and express firm believe on able leadership.The author has developed both graphical and mathematical model for Sustainable Total Living Environment (SusTLE) with the Participatory Development Process approach and Optimal Resource Allocation Process. The SusTLE Index i.e. comprehensive reflection of social, economic and environmental cost benefit ratios in the context availability of water, use pattern and recharging or storing and recycling of the same can accommodate physical / socio-economic and environmental sustainability. The pre-condition of implementation of the model is formulation of appropriate multi-stakeholders’ Neighbourhood Management Council (NMC), decision making body, which should have representation from community and consultant groups. The steps to be followed have been presented in Fig 3.
Screening committee
comprised of LocalCounselors
authority,Community
and other stake holders
Issues to be checked
Feasibility/SocialEconomicEnvironmental Resources
ViabilityCost benefitCost benefitCost benefit Constraints,
Comprehensive analysis & decision making through optimisation
Figure3. Decision making and resource allocation model – SusTLE
The right selection of representatives is vital for the development. This group will work as pressure lobby on authority about the community’s perception of satisfaction and sustainable development [8]. SusTLE model advocates transparency. Water is such an important issue, the combination of traditional knowledge and modern scientific information like aquifer details, depletion rate, recycling options, details like toilet flushing with less amount of water etc. has to be combined. Counselors like expert in settlement, hydrology, building design, will be of great help in the process. Proposal of new developments should integrate the water issue with proper relevance. The worth of proposal will be calculated in terms of resources investment and social, economical and environmental cost benefit ratio. Constraints and criteria of proposals will be detailed out like water level (below ground level), catchments area, run-off coefficient [8], quality etc. As better environment is the ultimate goal of SusTLE, the proposals with merit in environmental aspects will get premium in terms of added advantage. Some advantages like sanctioning extra budget or permission to build some extra volume etc. can be awarded. These will act as debentures to create enthusiasm for environment-friendly proposals.
CONCLUSION
- New developments should have integrated water management approach.
- Rainwater harvesting is an acceptable form of managing water but precautionary measures should be there to check quality of water through a clean process to catch and store and recharge the water.
- Planning and building byelaws should accommodate the provision of water management without any delay. No more filling of wetland should be allowed.
- Recycling of water can be opted in appropriate area. This can be used simultaneously for vegetable growing, pisci culture, recreational purposes.
- If right attitude could not be developed in the management of water, it will become a precious element whose abundance has been destroyed by the settlements’ unwise development. Attempt should be to train the children with right attitude.
- Model SusTLE is an appropriate model to follow for managing the water wisely.
REFERENCES
[1]United Nation Population Division, “World Urbanization Study” , UN, (2004).
[2]Pisharoty, P.R., “Meteorology for the Indian Farmers”, Indian Space Research Organization, Bangalore(1986),p-19
[3]Paul, S. , “Water harvesting in Delhi- need for sincere actions”,Spatio-Economic Development Record, Vol.9, No.1 (2002) p-22-28.
[4]Gopinath,K.R. “Rain Water Harvesting”, National Seminar on Rain Water harvesting, Central Ground Water Board, New Delhi, India (2000), pp-111.
[5]D.K.Chadha & U.Kapoor, “Rain Water Harvesting and artificial recharge- technological developments”, National Seminar on Rain Water harvesting,Central Ground Water Board, New Delhi, India (2000), pp-1-9.
[6]Mukherjee,M., “Design parameters for Human Settlements in a Mega city - Calcutta Case Study” Ph.D. Thesis, JadavpurUniversity. Calcutta, 2003.
[7]Mukherjee,M., “Habitat, Environment and Community in Cities” International Housing Conference 2000 (IHC 2000) organised by Housing Development Board, Singapore, May 2000.
[8]Dixit,M.J. & Patil,S.M., “Rain Water Harvesting”, Reaching the unreached- challenges for the 21st Century- 22nd WEDC Conference, New Delhi, India ( 1996), pp 364-365.