The boundaries between countries are political constructs which often do not take into consideration the distribution of natural resources. For example, rivers have been used as international boundaries for centuries and, although rivers may form logical barriers between people, they by definition fall in the centre of drainage basins. Political boundaries therefore divide water courses, river basins and groundwater aquifers. Where ever this happens the water course, river basin or aquifer becomes international. This complicates the management of water resources enormously. A good example of this is in Southern Africa where all rivers of size are shared between at least two countries and every country has at least 1 international river, with Mozambique has 9. (See the tables below)International water resources management is a complex process. Whilst it may lead to tension and stress between countries, it also provides opportunities for co-operation to maximize the mutual benefits of the resources. International water resources management requires both political and technical process which usually needs a legal basis through which to function. In many instances the institution which manages the process is a river or basin Commission. The establishment of all of the necessary elements often requires many years of negotiation and planning and is subject to many disruptions and hurdles which often have nothing to do with water.Countries regulate their relationships with regards to shared water courses through treaties, protocols, agreements and other legal instruments. These usually address such issues as water quality, water utilisation and abstraction, the construction of hydraulic structures such as dams and weirs for irrigation, hydro-power generation and flood management, notification and conflict resolution. For more detail see the International Water Law section of The Water Page. SADC states sharing international river basins Basin StateNumber of BasinsName of River Basin CoveredAngola5Cunene, Cuvelai, Okavango, Zaire, ZambeziBotswana5Limpopo, Nata, Okavango, Orange, ZambeziLesotho1OrangeMalawi 2 Rovuma, ZambeziMozambique9Buzi, Incomati, Limpopo, Rovuma, Save, Maputo, Pungue, Umbeluzi, ZambeziNamibia5Cunene, Cuvelai, Okavango, OrangeSouth Africa4Incomati, Limpopo, Maputo, OrangeSwaziland3 Incomati, Maputo, UmbeluziTanzania 2 Rovuma, Zambezi Zambia1ZambeziZimbabwe6Buzi, Limpopo, Nata, Pungue, Save, ZambeziMajor River basins and flows in southern AfricaRiverCountriesZaireAngola, Zaire, ZambiaZambeziAngola, Botswana, Malawi, Mozambique, Namibia, Tanzania, Zambia, ZimbabweBuziZimbabwe, MozambiqueCuvelaiAngola, NamibiaNataZimbabwe, BotswanaOrangeLesotho, Namibia, South AfricaPungueZimbabwe, MozambiqueIncomatiSouth Africa, Swaziland, MozambiqueShireMalawi, MozambiqueLuangwaMozambique, ZambiaOkavangoAngola, Botswana, NamibiaCuneneAngola, NamibiaLimpopoBotswana, Mozambique, South Africa, ZimbabweSave Mozambique, Zimbabwe
