Protecting the Rio Santa watershed in Peru

“What we need to do is improve the management of the entire basin”, said Marco Arenas, Head of the Huascaran National Park Authority in Huaraz, as he explained the water problems in the region to Mario Aguirre, IUCN Water Coordinator for South America.

Padlocks for Lake Parón water users, Rio Santo, Peru

The River (Rio) Santa flows south to north through the Callejon de Huaylas valley under the shadow of the Cordillera Negra, and the imposing Cordillera Blanca, the 2nd highest mountain range in the world. Glaciers in the Cordillera Blanca make up around 70% of annual flow in the Rio Santa, and also drain east to contribute to the headwaters of the Amazon.

Recent work by the National Meteorological and Hydrological Service of Peru (SENAMHI), the Development Research Institute, and the Glaciology Unit of the National Water Authority, highlights that flows from glaciers in the region will increase over the next 25 to 40 years as they melt. But this increase in flow will decline from 2050 onwards as the glaciers reduce in size. This could put the Rio Santa and the ecosystem services provided by the river under extreme pressure, especially during the dry season when between 70% to 90% of the river flow is glacier fed.

As Marco Arenas explains ‘the Santa river basin is an important economic area for the Ancash region of Peru. It contains gold mines, hydropower dams, irrigation systems growing export crops, and provides for the 1.8 million people living along the river’. Yet there are concerns over the long-term future of the river, not only because of reduced flows due to glacial retreat.

Mario Aguirre visited Huaraz many times to meet and talk to various stakeholders in the basin and start the implementation of the Water and Nature Initiative (WANI) activities along the Rio Santa. “Our first objective is to work with people to develop a participatory workplan and to try and understand the range of problems in this complex basin” said Mario. “The Huascaran National Park Authority is concerned with poor land use practices, over-grazing and soil degradation, affecting biodiversity, soil slope stability and species. However farmers are mainly concerned with the amount of sediment and the impact on canals and agricultural equipment”. Water quality is often mentioned as the common concern amongst stakeholders. Mining activities, dam tailings, agricultural run-off, lack of wastewater treatment and direct solid waste discharge into the Rio Santa make protecting the river a common challenge.

Direct action has already been taken to keep the water flowing. Lake Parón is a beautiful turquoise mountain lake at 4185m altitude. Water levels in the lake are controlled to protect the downstream population from flooding, and to provide a local dam with adequate flows for electricity generation. Disagreements over access to water and reliable flows for farmers between downstream communities and the operators of the hydroelectric plant, Duke Energy, led to farmers blockading access to the dam. Without access to the dam, Duke Energy was unable to regulate water flows into their hydro station for electricity generation needs.

Water sharing discussions eventually led to agreement between farmers and Duke Energy to improve communications concerning changes in water extracted from the lake. These discussions allowed for greater recognition of irrigation and downstream water needs previously not included in water allocation decisions. All parties must now agree to changes in flows from the lake, and all parties have an individual key for access to the water extraction facility.

“Managing the river with a better understanding of all the different water needs, accurate hydrological information and good decision-making is what we need’, said Arenas. The IUCN Water and Nature Initiative (WANI) is working in the Rio Santa basin to improve water resource management and the impacts of climate change on river flows. Adaptation to these changes, and increasing reliance on the river to provide ecosystem services for economic growth and development are at the forefront of WANI interventions in the basin.

For further information please contact:
Mario Aguirre
Water Coordinator
IUCN South America

Work area: 
Climate Change
Climate Change
Locally Controlled Forests
South America
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