Freshwater: A finite but renewable resource

Water, a critical component of the ecological cycles, is theoretically a renewable resource, made continually available -- through the water cycle -- by the constant flow of solar energy to the earth, which evaporates water from the ocean and redistributes it back to the globe as precipitation. As the world population increased, the water demand continued to rise and the per capita availability of freshwater continued to decrease. About 70 percent of the earth's surface is covered with water, but only 2.53 percent of that is freshwater, the rest being saline. Again, most of this freshwater is locked in ice and snow in glaciers and ice sheets. Only 0.26 percent of all freshwater stock (about 90,000 cubic km of water in absolute terms) is globally available to us for use -- from rivers, lakes, soil moisture and groundwater; apparently the quantity is not so small for a world population of 6.4 billion. In reality, however, we (humankind) are living at the mercy of the water cycle, which acts as the bloodstream of the biosphere.
As the world populations continue to increase, their expectations and water demand also rise, and the per capita availability of freshwater continues to diminish. Hence, the enormous amount of freshwater generated in the water cycle is being shared by more and more people, and is fast becoming a scarce commodity. Even though water is renewable, global stock of water is fixed, and hence, in real terms, freshwater is a finite resource. Moreover, as recognised in 1992 in the Dublin Conference on Water and Environment, freshwater is also an economic good. Assuming that water is a scarce economic commodity, water governance, therefore, is a crucial challenge for planners and managers. Water governance should essentially involve prudent development, optimal utilisation and efficient conservation of water resources.
Spatial imbalance
Owing to the unequal distribution of water resource in the planet and seasonal fluctuations in its availability, many countries are chronically water-stressed, while some countries -- like Bangladesh -- suffer from severe seasonal variations in water supply. Large inequality in the availability of water around the globe vis-a-vis population makes any assessment or statement on per capita water availability a meaningless exercise. For example, South America accounts for only six percent of the world population, though the continent is blessed with about a quarter of the global freshwater stock. On the other hand, 60 percent of the world's population live in Asia, yet the continent's water wealth is only around 36 percent of the global total.
Water and agriculture
Irrigated agriculture is by far the largest consumer of freshwater, withdrawing approximately 70 percent of annual renewable water resource, although domestic sector (safe water and sanitation) always claims the highest priority in water use. For some countries like Bangladesh, nearly 85 percent of water is used by the agriculture sector. This is not surprising because food production has been traditionally the main focus of agricultural pursuits; and for any country, the demand for food is 'not negotiable'. Water use (irrigation) in agriculture has turned many sunny, warm and fertile regions of the earth into important crop producing regions. Over two-thirds of the net sown area in Bangladesh is currently irrigated, making HYV boro rice the main rice crop of the year. With increasing use of irrigated water in agriculture, the productivity of agricultural land has certainly increased, as has the productivity of water usage in agriculture.
On the other hand, the lack of good governance in water-using crop production practices gives rise to unwanted social and environmental consequences. The list includes waterlogging and salinisation, aquifer depletion, wetland shrinkage as well as pollution (often irreversible). Worldwide, irrigation efficiency is still poor -- less than 40 percent; because much water is lost through evaporation/tran-spiration and drainage as a return flow; unfortunately a substantial part of it also picks up salts, pesticides and other toxic materials from the land, which return to the stream or the aquifer as pollutants. The water available for food production is closely linked to soil surface, texture and structure of the soil profile. Another close relation is with the land management practices. It is worth bearing in mind that land -- like water -- is also a finite resource at the same time as population growth is causing a steady decline in the global per capita availability of arable land.
Water and urbanization
Water management challenges differ substantially depending on the type of human settlements. There have been significant trends worldwide towards the growth of urbanisation. In most Asian and African countries, there is a steady stream of migration from rural to urban settlements. This is most notable in the burgeoning populations in the peripheries as well as in the inner city quarters of the world's megacities. In the developing world, Latin America is significantly more urbanized than Asia or Africa, although some of the world's largest cities are in Asia. In fact, nearly 48 percent of the world's urban population lives in Asia -- up from 32 percent in 1950.
Almost half of the global population currently lives in urban areas, and expansion of large cities continues at an accelerating rate. The largest and the fastest growing cities are all situated in countries with a low Gross National Income (GNI), e.g., Dhaka, Jakarta, Lagos, Mexico City. The implication of this is clear in terms of the seemingly insurmountable hurdles in obtaining good governance in the water sector. Fast growing urbanization has compounded the problem of water shortage affecting safe water supply, sanitation and drainage. Urbanization is not just a problem of water stress or scarcity; a major part of national, regional and global pollution is more likely to be generated in urban areas.
A good example of water predicament in megacities is Dhaka itself. With an estimated current population of over 12 million and at the daily average per capita demand of 160 liters, the city needs about 2,000 million liters of water per day. Dhaka WASA is unable to provide more than 80 percent of this requirement, some of which are also lost through pilferage and leakage (fancifully called 'system loss'.) By 2015, the city's population may exceed 20 million with a daily demand of about 3,200 million liters! At present, the major part of Dhaka's water is harnessed from groundwater sources. Although there is no structural evidence of land subsidence in Dhaka from groundwater withdrawal -- at least not yet -- it is a wise decision by the city's water managers not to go for groundwater abstraction any further and plan to access surface water, even if the offtake points have to be located at long distances on the Jamuna river. (The waters of the Buriganga and the Sitalakhya are too polluted for domestic use). Mexico City, which depended on groundwater for the city's water supply three decades ago, now withdraws surface water from a distance of over 200 km.
In the coming years, the struggle to achieve the Millennium Development Goals for water and sanitation will have to focus more on urban centers. This is where much of the economic activities and industrial production are concentrated and where most critical governance decisions are made. The stark reality is that water challenges in this century are becoming increasingly urban in nature.
Upstream-downstream water users
Water flows without any regard for political boundaries or frontiers. International river basins stretch across more than one country, and the sharing and utilisation of the basin waters frequently generate concern and disputes. Nearly 60 percent of all land in the world belongs to international river basins. Africa has 57 international river basins, Asia 49, Europe 48, South America 36, North and Central America 33. Across the world, there are dozens of international conflicts emanating from disputes between upstream and downstream water resource users. The most common international water resource conflict concerns water quantity or availability for the downstream user.
When an upstream country starts to withdraw or divert large quantum of water for irrigation or urban use, it diminishes downstream water flow and creates acute water shortage in the lean season -- as it happens in Bangladesh. Some of the well known examples of transboundary water disputes are in the Ganges Basin (arising out of the construction of the Farakka Barrage), the Tigris-Euphrates Basin (between Turkey and Syria/Iraq following the construction of Ataturk Dam), and between Jordan and Israel (following the latter's withdrawal of water from Lake Tiberias).
The optimal approach to the problem of transboundary water issues is basin-wide cooperation (including full transparency of data and information) among all the stakeholders in the basin, i.e., all the riparian countries who are water users in the basin. The potential for conflict can be transformed into a potential for cooperation. This cooperation should be viewed as 'cooperation as opportunity', emphasizing the ways in which shared watercourses would ensure optimal benefits to all stakeholders. Water in a transboundary river is a common international resource and sovereignty over such shared resources is best expressed as cooperation. In spite of the absence of any legally binding framework regulating the sharing of international water courses, cooperation and agreement in such river basins are not totally absent.
In 1999, 10 countries sharing the Nile Basin have launched a joint effort to promote basin-wide cooperation, known as the Nile Basin Initiative. In northeastern South Asia, there exist enormous potentials of cooperation among the countries sharing the basins of the Ganges, the Brahmaputra and the Meghna (GBM). Being the lowest riparian in all the above mentioned three river systems, Bangladesh is particularly concerned about water availability in its rivers during the lean season, especially because of numerous barrages, storage dams and diversion structures already constructed as well as being under-construction at upstream points in India. The immediate imperative, therefore, is to translate past promises of cooperation into reality, reaching equitable agreements of water sharing for all the common rivers between Bangladesh and India. Among the 54 transboundary rivers between the two countries, a sharing arrangement exists in respect to only one river -- the Ganges -- through the Ganges Treaty signed in 1996.
Since floods in Bangladesh are a common hazard, its management is not entirely possible without cooperation of the upstream countries. Such cooperation in the form of flood related data transmission from India to Bangladesh is in existence at an elementary level; however, data from more upstream stations on the GBM river basins would enable Bangladesh to forecast with a greater lead time, and thus enhance our flood preparedness capacity.
Besides agreements on water sharing and flood management, cooperation could also be effected through trilateral involvement (Bangladesh, India and Nepal) in constructing storage reservoirs in the Nepalese parts of the Ganges Basin. The northern and middle belts of Nepal (having a low population density) offer excellent sites for such reservoirs. These storages would not only help in flow augmentation in the Ganges during the dry season and flood moderation in the rainy season, but would also generate environment-friendly hydropower in Nepal for export to Bangladesh and northern India. (Nepal has a potential of 83,000 MW of electricity, of which 40,000 MW is economically feasible for development). Bangladesh could be involved in the implementation of these multipurpose projects through agreed formula for sharing costs and benefits.
The challenge of governance
In the backdrop of rising demands for water in the domestic, agriculture and urban sectors, and among the coriparians in the transboundary basins the key to good governance in water utilization is to follow a holistic vision of Integrated Water Resources Management (IWRM). IWRM is based on the perception of water as an integral part of the ecosystem and is defined 'as a process which promotes coordinated development and management of water and land in an equitable manner'. Water governance aims at decision making in an optimal framework, dealing with decisions on water quantity, water allocation, pollution level, and conservation for the next generation. It also determines the share of water between upstream and downstream water users -- especially ensuring the latter's right to sustainable livelihood.
The governance challenge might also include within its paradigm a concept, advocated by some hydrologists, which seeks to integrate land use with water management. Since land use modifies ecosystems, including water; a land use decision or choice is also a water use decision. Both the vital resources play a synergistic role and hence, a better strategy could be to develop a vision of 'Integrated Land and Water Resources Management' (ILWRM) in order to develop and manage two scarce natural resources -- water and land.
Dr. Rasheed, a former Professor of Geography and Environment, University of Dhaka, is currently teaching Water Resources Management at Independent University, Bangladesh.