Watering the Atacama Desert: Keeping the Rio Huasco Flowing
The Huasco River in the Atacama Region of Chile is no typical river. Fed by glaciers straddling the Chile and Argentina border high up in the Andes, the river is formed by the confluence of the Del Carmen and Del Transito tributaries. Halfway along the river from source to sea the Santa Juana Reservoir stores the water for irrigation needs – mainly for grapes grown for export and olives for oil. The river continues to flow through Vallenar, the capital of the Huasco province, eventually entering the Pacific Ocean at the coastal town of Huasco.
But the river is not typical because it hardly flows. The Atacama is one of the driest places on Earth, in places receiving no rainfall as the desert is blocked from receiving moisture on the East by the Andes, and in the West by the Chilean Coastal Range. Maintaining the flow of the Huasco river is crucial to sustain the livelihoods dependent on it, the farming communities and export businesses which have developed in the region - and the ecosystems dependent on the river flows from the glaciers, shallow groundwater flow from springs, and the rare rainfall events.
Yet residents in the Huasco Basin are concerned – concerned they may go the same way as neighbouring town Copiapó 140km to the North. Copiapó has received no rainfall for the last 10 years. In recent years the Copiapó River has dried up due to mining and agricultural activity in the region and the future of Copiapó is unknown as residents grapple with the concept of leaving their homes and their land due to water scarcity.
A new project involving the Water and Nature Initiative, partners Centro del Agua para Zonas Áridas y Semiáridas para América Latina y el Caribe (CAZALAC), the regional office of the Direction General of Water Resources of Chile (DGA), the regional office of the National Environmental Council of Chile (CONAMA), Proyecto Territorial Integrado Huasco of CORFO, the Regional Intendancy (Atacama Region), the Irrigation Water Users Boards (Junta de Vigilancia del Río Huasco), the Regional Water Resources and Environment bodies, and Fundacion Chile aims to work with stakeholders in the Huasco Basin to try and improve water management in the basin, as well as to develop an environmental flows assessment in order to maintain future river flows.
The controversial Pascua-Lama open-pit mining project high in the mountains brings significant revenue to both Chile and Argentina and employment for the region. But the proximity of the mine to the glaciers, the source of the Huasco River, has caused controversy and public protest in Chile, including demonstrations and petitions presented to the Chilean government. Opponents to the mine argue that the project will affect the river flows and therefore farmers dependent on the water supply, including reducing water quality.
Transferred water rights between agriculture and mining may be affecting the availability of water downstream for farmers, yet regulation and monitoring of water distribution is difficult where land ownership is private and water rights are complex. Future planned development in the basin, and expanding land use for agriculture is also extracting more water from the river, at times reducing flow to zero along the river channel. These elements all pose difficult challenges for water management and new approaches to water allocation are needed.
In October last year IUCN were involved in an International Seminar in Vallenar in the centre of the Huasco Basin, to highlight the role of environmental flows in restoring and maintaining river flows for all users. The seminar was well attended by many local residents who voiced their concern at the risk of over-allocating precious water resources, declining groundwater levels, and growing fears over the water quality in the river.
Local partners CAZALAC, DGA, CONAMA, PTI, and others, with the support of the IUCN Water Program are leading the project focussing on determining the best approach to implement environmental flows to maintain ecosystem services from the river. Competing water uses range from mining, a coastal wetland, agriculture, recreation, and future developments such as the largest intensive pig farm in Chile. A recent proposal by Hidroelectrica Rio Huasco for the construction and operation of a hydroelectric plant using irrigation water stored in the Santa Juana reservoir may also affect flow timing and releases from the dam, affecting the needs of irrigation and the environment.
Although the Rio Huasco is an extreme case of climate and human induced impacts on a river, more and more water from rivers is becoming over-allocated as economic growth and uncoordinated water management reduce the amount of water left in our rivers.
For more information please contact Mario Aguirre, Water Coordinator, IUCN South America, Quito, Ecuador, firstname.lastname@example.org.