This paper is concerned with the interface between land tenure rights and water rights. Such rights relate to what are arguably the most important natural resources of the modern nation-state. Land, in the form of territory, is a pre-requisite for a state's existence while freshwater is a pre-requisite for life.
The relationship between these two resources is of equal significance. Water is necessary for most productive uses of land. In a growing number of countries with arid climates the main constraint to agricultural growth is the availability of water rather than land. At the same time the use of land has major impacts on both the quality and quantity of water resources. In other words, decisions regarding the use and allocation of one resource impact directly or indirectly on the use and allocation of the other. To ensure sustainability, the need for an integrated approach to the use and management of these resources is increasingly recognized.
The principal mechanism for the allocation of land and water resources is the institution of legal rights: land tenure rights and water rights. The substance of such rights and the manner in which they are allocated have major implications for the use and management of land and water resources as well as for the social and economic development of states and their citizens, with particular impacts on the livelihoods of the poor.
At the outset it is important to recognize the fundamentally important role that land tenure rights have played throughout history in the socio-economic development of states and nations, a role that they continue to play. A primary production factor, source of employment and repository of personal wealth, land performs an economic function of paramount importance. In many societies, both social status and power depended, and indeed continue to depend, on the size and structure of land holdings. What form land tenure rights should take and how those rights are or should be allocated therefore raise questions that are fundamentally political in nature. The answers to those questions, in the shape, form, content and allocation of land tenure rights, land tenure regimes and reforms to such regimes are themselves symptomatic of what are ultimately ideological expressions of the relationship between humans and the land.
For centuries lawmakers have used private property, including land, as a tool to stimulate individual enterprise and economic growth. Very often such growth has been at the expense of the poor and the landless or those rendered landless. Revolutions have been fought and political fortunes have waxed and waned over the issues of land rights and land reform. Indeed land reform, or the absence of land reform, remains an acutely sensitive political issue in many parts of the world. Following the end of the cold war, current orthodoxies, as reflected in the policies of governments and donor agencies, emphasize an increased role for private land rights, private property and the liberalization of market transactions in the land sector.
In many jurisdictions, water rights have for a long time been considered as a subsidiary component of land tenure rights, a right to use water often being dependant on the existence of a land tenure right. In contrast to land tenure rights, however, debate over water rights and their reform has tended to be less concerned with ideology than with hydrology, with hydraulic engineering than with social reform. In short, water rights have had a much lower popular profile than land tenure and land rights.
In part this is because although water is necessary for most productive uses of land, water rights are not. To take the case of agricultural land, in temperate climates sufficient moisture is provided from rainfall to permit the growth of crops and other vegetation. Irrigation is simply unnecessary thus obviating the need for water rights. As regards urban and peri-urban areas, most land is supplied with treated water through piped water supply networks. While the supplier will generally need to hold water rights in respect of any water that it abstracts from a natural source, households and commercial users connected to such a network rely on the supplier's statutory duty to provide them with wholesome water, rather than on water rights. Generally speaking, in urban and peri-urban areas water rights are of little practical concern to most water users other than the operators of market gardens and large industrial enterprises, such as factories and power stations, which may hold their own separate water rights: this is often cheaper than relying on treated drinking water from the water supply system.
However, in jurisdictions with arid climates or in times of drought and water shortage water rights rapidly climb national political and socio-economic agendas. The traditional response to water shortages has been an engineering response, through the construction of dams to store water and canals and pipelines to convey it to those places where it is needed. An increased awareness of the environmental costs of this kind of approach and a growing reluctance on the part of governments to meet the financial costs, together with the fact that in many cases the cheaper and easier schemes have been constructed, means that increased focus is being placed on the better management and allocation of available water resources.
Indeed as the world's water resources come under increased pressure, the importance of water rights is likely only to increase. Already, around one third of the world's population live in countries that suffer from moderate to high water stress. Continued population growth and the effects of climate change, a phenomenon whose eventual impacts are not yet fully understood, suggest greater pressure still: it is reckoned that the demand for water will increase by around 50 percent in the next 30 years and that around 4 billion people, one half of the world's population will live in conditions of severe water stress by 2025.
Much of this increased demand will come from irrigated agriculture which is particularly sensitive to small temperature variations. Agriculture is already the main water use sector in many countries around the world and generally the sector in connection with which most water rights are held. In many jurisdictions the economic value of land tenure rights that relate to irrigable land often depends directly on the existence of adequate water rights. At the same time, demand for water from the world's rapidly growing cities is almost certain to increase. It is common, particularly in newspapers and the popular media for discussion of this subject to be held in terms of increased scarcity of water resources and of shortages. In reality, the volume of freshwater on the planet has been remarkably constant over the millennia. Increased pressure on water resources is a result of population increases as well as economic growth. In other words much of the scarcity of water is socially defined and a key role is played in this process by water rights that define who has access to water - and who does not. It is against this background that water rights, and decisions about water rights, will play an increasingly important role over the coming years, a role that will invariably impact on decisions and choices concerning the use of land.
Largely as a response to increased concerns about the quality and quantity of water resources, the last thirty or so years have seen many countries undertaking substantial reforms to water sector legislation and thus to water rights. In contrast to the trend towards private ownership and private rights in the land tenure sector, reforms to water legislation have seen the assertion of state control over water resources and the introduction of complex regulatory mechanisms for the allocation of administrative water rights. Furthermore, in a number of jurisdictions, such water rights have become fully tradable and there is currently much speculation as to the extent to which this approach may be replicated elsewhere.
Yet notwithstanding the importance of land tenure rights and water rights, and the fundamental relationship between the resources to which they relate, a preliminary literature search suggests that relatively little comparative analysis has been undertaken of the two regimes and the interface, or relationship, between them.
This paper sets out to begin the process of exploring that interface. It seeks to answer a number of basic questions. First of all just what are land tenure rights and water rights? Second, how do the respective regimes compare? Third what linkages, if any, are there between land tenure rights and water rights and, if there are none, does this matter, either in general or as regards specific aspects of the interface? A key objective of the paper is to examine which aspects of the rights interface merit further research. In comparing the two regimes a final subsidiary objective of this paper is to try and identify which areas, if any, in one sector can shed light on areas for future research in the other.
This paper is based on a comparative analysis of different land tenure and water regimes around the world. In this connection it is important to note the extreme variability in land and water resources among states. Although the variability in the total land area of each state can be quickly gleaned from viewing a map of the world the variability in availability water resources is equally marked, irrespective of land area. Of course the pressures on both land and water resources can only be understood by reference to population levels and, as noted above, the total useable land area within a state's borders may often depend on the availability of water. In short, each country faces unique water issues as well as unique pressures on its land resources.
 The existence of territory
is a pre-requisite for the recognition of a state pursuant to international law.
Jennings, R. and Watts, A. (Eds). 1992. Oppenheims International
Law, London, p. 121.|
 For example, the increasing scarcity of agricultural land in the arid Near East is caused by serious water shortage and the high costs of irrigation. El-Ghonemy, M.R. 1996. Recent changes in agrarian reform and rural development strategies in the Near East, FAO Paper Presented to the Rural Development International Workshop Held at in Godollo Hungary, 9 - 13 April 1996, p. 9.
 Largely as a result of the lack of available land and water the projected increase in the number of people living in absolute poverty in the predominantly affluent Near East (excluding Pakistan, Afghanistan and Somalia) from 80 million in 1990 to nearly 100 million in 2000. El Ghomeny, op cit.
 Vogelsang, F. 1998. After land reform, the market? FAO paper, p. 21.
 Freyfogle, E.T. 1999. The Particulars of Owning, 25 Ecology Law Quarterly 574, p. 583.
 In Southern Africa, for example, as well as in Brazil where in July 2003 President Luiz Inacio Lula da Silva reiterated to landless workers' leaders his commitment to wide-ranging land reform. BBC Website http://news.bbc.co.uk.
 Without water, without moisture to hold its soils together, land has few productive uses, particularly land that is subject to land tenure rights. Land used for roads and other communication links, car parks, waste disposal sites, may not actively need water. But all human activities around that land certainly will. And while otherwise barren land may contain oil or other mineral wealth beneath its surface, water will almost inevitably be needed for the extraction of those resources.
 Historically a municipal or public body but increasingly a private water supply company.
 In this connection the important role of urban agriculture in Africa is to be noted. In Accra, Ghana, for example an estimated three percent of the citys labour force is engaged in urban agriculture which supplies some 90 percent of the citys vegetable supplies (Amuzu and Leitman, Environmental Profile Accra, case study prepared for the Urban Management and Environment Component, UNDP/World Bank/UNHCS Urban Management Programme 1991). It is an important component of household survival strategies for the urban poor, as well as a source of livelihoods and food for them. It has the potential to provide jobs for the urban unemployed (Maxwell D. and Zziwa S. 1992. Urban Farming in Africa: the case of Kampala, Uganda ACTS Press, Nairobi). However, such activities often take place on land without secure tenure and without secure water rights, relying on wells and sometimes on wastewater.
 This is particularly the case when the rights of urban water suppliers are affected, thus leading to restrictions on the use of water by the affluent such as for swimming pools and garden sprinklers.
 With conditions particularly severe in Africa, the Middle East and South Asia. World Bank, 2003. Water Resources Sector Strategy: Strategic Directions for World Bank Engagement World Bank, Washington D.C., p. 1.
 Even in England, with its famously damp climate, an increase of 52 percent over the 1995 figure is estimated for irrigation water demand by 2021. Bough, J. 2002. Water abstraction and agriculture: Towards sustainable use of water resources 2 Environmental Law Review 234, p. 235.
 In many parts of California, for example, the value of agricultural land is almost entirely dependent on the existence and availability of water rights.
 McCaffrey, S. 2001. The Law of International Watercourses - Non-navigational uses, Oxford University Press, Oxford, p. 4. Having said that, recent research suggests that in some parts of the world climate change is causing glaciers to melt and this will in fact have a significant impact on the volumes of water available for abstraction from rivers that are fed from glacier melt, such as many of those in Central Asia.
 Soussan, J. 1999. Water/Irrigation in Sustainable Rural Livelihoods in Carney, D. (Ed) Sustainable Livelihoods - what contribution can we make? London, DFID, p. 187.
 Of particular relevance among the relatively small number of works that do address this issue are: Huggins, C. 2002. Rural Water Tenure in East Africa: a comparative study of legal regimes and community responses to changing tenure patterns in Tanzania and Kenya, African Centre for Technology Studies, Nairobi; Derman, B., Ferguson, F. & Peters, P. 2002. Promoting Equitable Access to Water Resources¸ Brief No. 12, University of Wisconsin, Madison; and Kirsten, J., Perret, S. & Van Zyl, J. 2000. Land Reform and the New Water Management Context in South Africa: Principles, Progress and Issues, Paper prepared for a seminar of the Natural Resources Management Cluster and Land Policy Thematic Group, The World Bank, Washington DC 27 September 2000 both of which address the relationship between land tenure rights and water rights reforms in Southern Africa; Bjornland, H. & OCallaghan, B. 2003. Property Implications of the Separation of Land and Water Rights Paper presented at the North Annual Pacific-Rim Real Estate Society Conference, Brisbane, Queensland 19 - 22 January 2003 which addresses the implications for land tenure rights of making water rights tradable.
 At a country level there is extreme variability in total renewable water resources (TRWR): from a minimum of 10 m3/inhabitant in Kuwait to more than 100 000 m3/inhabitant in Canada, Iceland, Gabon and Suriname. For 19 countries or territories the TRWR per habitant is less than 500 m3; and the number of countries with less than 1000 m3/inhabitant is 29. Within states there can be extreme spatial and temporal variability either throughout the year or between years. FAO, 2003. Review of world water resources by country, Rome.
 Percy, D.R. 1999. Security and flexibility in water rights - lessons and pitfalls in modern Canadian legislation, Paper presented to the Third International Water Law Conference, Dundee Scotland, p. 4.