The water resources management system in Uruguay has been influenced by the general sense of water as an abundant resource in the country. Average annual rainfall is 1,182 mm, representing a contribution of 210 km3 annually throughout its territory. In 2002, the per capita renewable water resources was 41,065 cubic meters, way above the world average 8,467 m3 in 2006. Uruguay also shares one of the largest groundwater reserves in the world, the Guarani Aquifer, with Brazil, Argentina, Paraguay. The Guarani aquifer covers 1,200,000 square kilometers and has a storage capacity of 40,000 km3.
The institutional framework for water resources management consists of sectoral governmental agencies at the national and regional level. The Water Code, Decree No 14.859 of 1978, establishes the legal framework for water resources management in Uruguay completed by sectoral laws for agriculture, industrial water use, energy production and water supply and sanitation.
Water resources base
Surface and groundwater resources
Uruguay has six major watersheds, Uruguay River, Plata River, Atlantic, Merin Lake, Negro River and Santa Lucía River. All watersheds in Uruguay but Santa Lucia share water with other countries such as Brazil and Argentina. Surface water is the main supplier of water for irrigation (87%), domestic (11%) and industrial use (2%). Irrigation is the main water user by watershed, except in the Santa Lucia River (domestic use) and the Plata River (industrial use).
Groundwater resources supply water to some small urban settlements and small and medium scale irrigation systems in the interior. The most important groundwater reserves in Paraguay in terms of capacity are the Guaraní and the Raigon Aquifer. The Guarani aquifer is one of the largest groundwater reserves in the world, covering 1,200,000 km2 throughout Brazil, Argentina, Paraguay and Uruguay. The Guarani Aquifer has a storage capacity of 40,000 cubic kilometers. With an estimated annual recharge rate of 160–250 km3 and more than 40 km3 available for consumption, the Guaraní aquifer could supply daily 300 liters of water per capita to 360 million people. The neighbor countries are implementing an Environmental Protection and Sustainable Management project together with the Organization of American States and the World Bank.
Source: Ministerio de Vivienda, Ordenamiento Territorial y Medio Ambiente
Storage capacity
According to the Food and Agriculture Organization, the Uruguay River and the Negro River have the largest concentration of Uruguay’s big dams, aimed mostly at hydropower generation, with a total storage capacity of 17.3 km3. Large dams in Uruguay include:
the Salto Grande dam on the Uruguay River on the border with Argentina, inaugurated in 1979, with a 1,890 MW power plant and a storage capacity of 5 km3 the Rincón del Bonete dam on the Negro River, inaugurated in 1945, with a 160 MW power plant and the largest reservoir in the country with a storage capacity of 8.8 km3 the Baygorria dam on the Negro River, inaugurated in 1960, with a 108 MW power plant and a storage capacity of 0.6 km3 the Palmar dam on the Negro River, inaugurated in 1980, with a 333 MW power plant and a storage capacity of 2.85 km3
Other medium dams for industrial and irrigation purposes are located in the Santa Lucia River (Canelón Grande Dam), Rocha Department (India Muerta Dam) and Minas de Corrales. In addition, there are many small private minor reservoirs throughout the country aimed mostly at irrigation with an estimated storage capacity of 1.4 km3.
Water quality
The Ministry of Housing, Territorial Organization and Environmental (MVOTMA for its acronym in Spanish) considers that water quality in Uruguay is slowly decreasing due to the release of untreated effluents from industries and cities as well as agricultural runoff. In addition, uncontrolled groundwater use can lead to pollution or overexploitation of aquifers. In the Departments of Canelones and Maldonado, overexploitation has cause sea water intrusion into coastal aquifers and bacterial contamination.
Water resources management by sector
Drinking water and sanitation
Uruguay is the only country in Latin America that has achieved quasi universal coverage of access to safe drinking water supply and adequate sanitation. Water service quality is considered good, with practically all localities in Uruguay receiving disinfected water on a continuous basis. 70% of wastewater collected by the national utility was treated. Given these achievements, the government's priority is to improve the efficiency of services and to expand access to sewerage, where appropriate, in areas where on-site sanitation is used.