Regional Leadership Forum Advancing Sustainable Hydropower in Latin America and the Caribbean

1. Downstream Flow Regimes
Regional Leadership Forum – Advancing Sustainable
Hydropower in Latin America and the Caribbean

2. 1. Downstream Flow Regimes
(Ecological Flows)

3. Evolution in Recognition of the
Issue
Terminology Main Objectives
“Sanitary” Flows (static or discrete Dilution
values)
Minimum Flows (static or discrete Downstream Water Uses
values) Third Party Impacts
In-stream Flows (hydrographs) Fluvial Geomorphology / Ictiofauna
Ecological Flows (hydrographs) Species / Biota
Downstream Flow Regimes Ecosystems + return flows
(hydrographs + adaptation)
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4. Environmental/Ecological
Flows - Timeline
 Until 1960s: Water management in developed nations focused largely on maximizing flood
protection, water supplies and hydropower generation.
 1970s and 1980s:
 Ecological and economic effects of hydroelectric projects prompted scientists to seek ways
to modify reservoir operation to maintain target fish species (salmon);
 The initial focus was to determine the minimum flow necessary to preserve individual
species. The minimum flows concept evolved to instream flow objectives.
 1990s:
 Scientists realized that the biological and social systems supported by rivers are too complex
to be represented by a single minimum flow requirement;
 Restoring and maintaining more comprehensive environmental flows gained increasing
support. Scientific methods to define downstream flow regimes focusing on maintaining a
broader spectrum of reverine species, processes and services.
 2007: The Brisbane Declaration on Environmental Flows was endorsed by more than 750
practioners from more than 50 countries. The declaration announced an official pledge to work
together to protect and restore the world’s river and lakes;
 By 2010: Many countries had adopted environmental flow policies.

5. 2. Chaglla Hydroelectric Project

6. Project Location
Tingo María
PERU
Huánuco
LIMA
Road Distance Lima – Huánuco : 420 km
Road Distance Huánuco – Obra : 130 km

7. Project Characteristics
Dam
Type Rockfill Concrete Face
High 199 meters
Length 400 meters
Reservoir
Storage Volume 345 hm³
Reservoir Area 4,66 km²
Aduction Tunnel
Length 15,6 km
Diameter 7,6 m
Power and Generation
Main Powerhouse 400 MW
PCH 6 MW
Execution Period
54 months
Investment
USD 1.2 billion

8. Downstream Flow Objectives
Dam Details
Powerhouse Details

9. Project Location
 Peru - Ley de Recursos Hídricos (Water Resources Act):
• Ecological Flow Definition: The water volume that has to be kept in natural systems
for the protection and conservation of local ecosystems, the landscape aesthetics or
other aspects with cultural and scientific interests;
• The Water Authority in Peru will establish the ecological flow in each river;
• Ecological Flows will be defined in each basin’s Water Resources Management Plan.
For the definition of the Ecological Flow specific studies will be performed for each
stretch of the basin.
 Projects with water exploitation to produce energy must perform specific studies to
determine the Ecological Flows for the affected stretch;
 The Water Authority in Peru (ANA) has not yet established a standard methodology to
determine ecological flows.

10. Ecological Flow Management Plan
 Phase 0 – Adjusting location to reduce length of impacted reach (improved hydrology);
 Phase 1 – Understanding systems characteristics (hydrology, ecosystem, species,
topography, water uses, etc.) and validating the proposed approach (mathematical
modeling) – critical to preserve and/or restore key tributaries;
 Phase 2 – Improve knowledge of the system, refine and consolidate modeling framework,
identify critical areas and issues. Develop a blueprint to resolving critical obstacles;
 Phase 3- Implementation of physical interventions;
 Phase 4 – Operational – continuous monitoring and adjustment to changing conditions.
Carachama (Chaetostoma sp.)

11. Lessons Learned
• Increasing Complexity
• Understanding the Characteristics of the Ecosystem;
• Incorporate ecological flow objectives early (upstream) in your decisions
making process (project identification);
• Definition of objectives (target species, sediment transport, cultural values,
existing and potential water uses, connectivity, etc.)
• No “one size fits” all formula
• Focus on principles and best practices – flexibility
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12. Ecological Flow Management Plan
 Partnership involving the Government of Peru, IDB and Odebrecht;
 Beyond the project specific solutions the process is developing and disseminating
knowledge to contribute to development of regulatory frameworks and
methodologies as well as to improved solutions for future projects.
AXIS OF THE DAM
DIVERTION
TUNNEL OUTLET

13. THANK YOU
Luiz Gabriel Todt de Azevedo
gazevedo@odebrecht.com