Glacial Lake Handbook (Technical Report), by Cesar Portocarrero

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Although glacial lake outburst floods (GLOFs) have occurred repeatedly in many places around the world, perhaps no country has as much experience with managing such lakes as Peru. This technical report is a distillation of the experiences and knowledge acquired during seven decades of active lake management. The goal is to provide lessons learned and case studies that may benefit the global community as each country addresses its own glacial lakes issues. We stress that local efforts will need to adapt to the unique context of each lake, valley, and country, and that each case requires action based on the best locally available knowledge and engineering.

Peru, along with other developing countries, must rely on limited research across the wide range of disciplines that are important to glacial lake management, including geography, climatology, anthropology, animal science, and botany, as well as the social and political sciences. Mitigation strategies should involve the development sector because managing water as a resource is as important to many local populations as is disaster risk management for GLOFs. Wisely managing glacial lakes requires inter-institutional work that is most productive when done cooperatively.

The Glacial Lake Handbook: Reducing Risk from Dangerous Glacial Lakes in the Cordillera Blanca, Peru, is currently in DRAFT form. Please recognize that contents may change prior to final formatting.

Please find the Preface under the Table of Contents. Download the 10MB PDF here or from the link at the bottom of this page.

Table of Contents:

Glacial Lake Handbook cover

  • Preface
  • USAID support to work on glacial lakes in Peru

1.  Overview of glaciers, glacial lakes, and management practices

  • 1.1    Purpose of this report
  • 1.2    History of Peru’s National Water Authority Glaciology Unit as historical background to this report
  • 1.3    Factors that influence risk management of glacial lakes
  • 1.3.1         Glacier characteristics
  • 1.3.2         Slope of the bedrock
  • 1.3.3         Geometry and structure of moraines forming the lake basin
  • 1.3.4         Length and slope of the downstream valley
  • 1.3.5         Presence of hanging glaciers
  • 1.3.6         Glacier tongues undermined by glacial lakes (calving)
  • 1.3.7         Volume of the lake
  • 1.3.8         Seismic and tectonic factors
  • 1.3.9         Discharge rates
  • 1.3.10       Determining the potential trigger
  • 1.4    Moraines and their structure
  • 1.5    Process leading to glacial rupture and potential ice avalanches
  • 1.6    Social policy considerations in glacial lake management
  • 1.7    Methodology for reducing the risk from dangerous glacial lakes

2.  Geological and historical background to case studies in Cordillera BlancaGlacial Lake Handbook title page

  • 2.1    Overview of the Cordillera Blanca and the Callejón de Huaylas
  • 2.2    Basic geology and glacial history of the Cordillera Blanca
  • 2.3    Primary natural disasters in Peru
  • 2.4    Glacial lakes in the Cordillera Blanca

3.  Case studies from Peru

  • 3.1    Palcacocha Lake
  • 3.2    Parón Lake
  • 3.3    Lake 513
  • 3.4    Safuna Alta Lake
  • 3.5    Jancarurish Lake
  • 3.6    Huallcacocha Lake
  • 3.7    Paccharruri Lake
  • 3.8    Llaca Lake
  • 3.9    Hatuncocha (Big) Lake
  • 3.10  Llanganuco Lakes
  • 3.11  Lake 69
  • 3.12  Cuchillacocha Lake
  • 3.13  Tullparraju Lake
  • 3.14  Shallap Lake
  • 3.15  Allicocha Lake
  • 3.16  Lazo Huntay Lake
  • 3.17  Riticocha Lake

4.  Literature cited and bibliography on glacial lake management in Peru


Mountain areas are particularly vulnerable to the impact of climate change. Today’s rapid snow and glacier melting initially increases runoff in some regions, but lack of a glacial buffer ultimately causes decreased reliability of dry season stream flow, affecting water supply, agriculture, ecosystems, and hydropower. These changes are superimposed on other drivers in local society and are having profound impacts on mountain communities and downstream populations, especially in the heavily glaciated Hindu Kush–Himalayas and Andes regions. The changes pose unique challenges for adaptation to climate change, including more variable seasonal patterns and increased threats of glacial lake outburst floods (GLOFs), which have strong impacts on regional social, environmental, and economic systems. Considerable uncertainty surrounds future water supplies, storage, and hazards in changing climate patterns.

Since the 1940s, Peru has experienced what most experts are now predicting for other glaciated mountains throughout the world, i.e., shrinking glaciers with emerging lakes that sometimes release deadly GLOFs. This long Peruvian experience has led to expertise in glacier hazard management that is perhaps unmatched in the world. The first local risk-reduction efforts in Peru’s major mountain range, the Cordillera Blanca, began in 1942 after a GLOF destroyed much of the city of Huaraz, killing an estimated 5,000 people. Nine years later, in 1951, the national government officially established the Control Commission of Cordillera Blanca Lakes that is today known as the Glaciology and Hydrological Resources Unit. The glaciology office conducted engineering projects to reduce the risk of 34 dangerous glacial lakes. By draining and containing glacial lakes before they produced outburst floods, these engineers have likely prevented many catastrophes. It is believed that these efforts saved the cities of Huaraz in 1959, Huallanca in 1970, Carhuaz in 1991, Huaraz in 2003, and Carhuaz again in 2010. And that’s only the known close calls, because most of these lakes lie high in the mountains where events go unnoticed.

Working with limited government resources—a situation similar to that of Nepal and other developing countries—Peru’s Glaciology Unit is now a leader in tropical glacier research and glacial lake engineering to prevent outburst floods. So that the world may benefit from this Peruvian expertise, the USAID-funded High Mountains Adaptation Partnership (HiMAP) feels that this knowledge should be shared with mountain dwellers worldwide. The following technical report, The Glacial Lakes Handbook, captures the lessons learned by Ing. César Portocarrero Rodriguez over the course of a 40-year career devoted to the reduction of glacial lake outburst flood risks in the Cordillera Blanca. We hope that the experience and guidance provided by the Handbook will be of use to scientists, engineers, decision makers, and local people in other regions of the world currently experiencing the phenomenon of receding glaciers accompanied by the formation of potentially dangerous lakes.

Alton C. Byers and Daene McKinney, HiMAP Co-Managers, November 2013

Download DRAFT VERSION 5 of the Glacial Lake Handbook from the link below.


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Glacial Lake Handbook
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