Multipurpose Water Storage,

an international perspective

Alessandro Palmieri, Water Infrastructure Adviser

OUTLINE

Why Multiple Purposes?

A couple of not so usual purposes

ICOLD Committee on Multipurpose Water Storage (MPWS)

MPWS Working Groups highlights

Opportunities and Challenges

Multi-purpose dams are very robust producers of major streams of benefits as economies develop, as circumstances change and as societal values evolve.

At the same time, the decision-making process to realize a multipurpose water project if very often a challenging one.

The Financial Gap

Water infrastructure projects often fall in the gap between economic and financial viability.

A project can be economically attractive and represent the preferred option when seen from a long-term national perspective, but when considered as a commercial investment it may be unable to generate adequate financial returns.

Three reasons for considering multipurpose objectives

Dam sites, particularly storage sites, are scarce national resources, and so it makes sense to consider how to extract maximum benefit from them.

Since civil works can last for 100 years or more, they should be viewed as genuinely long-term investments, which argues for flexibility in use over time.

As global warming contributes to increasing variability in rainfall, agricultural production, floods, etc., storage becomes more valuable, and dam projects need to be designed with this in mind.

Some less usual purposes

Sediment management in the downstream river course

Prevention of ice jam formation

Protection from upstream outburst floods (glacial lakes, barrier lakes, etc.)

Artificial wetlands

Barrier to saline water intrusion

Micro-climate around reservoirs

A couple of examples

Sediment management in the downstream river course

Prevention of ice jam formation

Protection from upstream outburst floods (glacial lakes, barrier lakes, etc.)

Artificial wetlands

Barrier to saline water intrusion

Micro-climate around reservoirs

Xiaolangdi Multipurpose ProjectandYellow River Sedimentation Reversal

THE PROBLEM

In Kaifeng, the riverbed is more than 10m above the city

River bed raise 100 mm/year

Disastrous consequences when dykes break

1km long physical model (moving bed) for 900 km of river course

DESCRIPTION (July 2002):

Flushing lasted 11 days.

Average discharge 2,740 m3/s.

Volume released 2.61 billion m3.

The test interested a total length of 800 km of the Yellow River.

Gates at Sanmenxia and Xiaolangdi were operated 294 times.

OUTCOME:

362 million tons of sediments moved onto the estuary in the N-E China Sea (800 km downstream).

Reservoir Flushing

Artificial wetlandsKanna Dam, Japan

Reservoir Storage Modifies River conditions ….. and creates Wetlands

DeltaDeposits

Wetland formatio

n

The reservoir-created

wetlands ….

.. have become a tourist attraction

ICOLD Committee on Multipurpose Water Storage (MPWS)Launched in Seattle, August 2013

Time frame 3 years

ICOLD member countries involved: Brazil, Canada, China, Ethiopia, France, Iran, Japan, Korea, New Zealand, Nigeria, Russian Federation, South Africa, Turkey, UK, United States.

Chair: Alessandro Palmieri (Italy), Vice Chair: Li Wenxue (China)

ICOLD (MPWS)Objectives

Recommend essential elements and emerging trends for planning and implementation of multipurpose water storage (MPWS) ……

…. as economies develop, as circumstances change and as societal values evolve.

Three Working Groups

Group 1: Case studies and literature review

Group 2: Economic and Financial aspects

Group 3: Long Term Planning

China: Xiaolangi Multipurpose

Xiaolangdi: the financial gap

Total costs US$3.5 billion, US$1 billion for resettlement. Completed one year ahead of schedule; cost savings 300 MUS$.

Multipurpose reservoir: Flood control, Sedimentation management, Maintaining adequate in stream flows, Replacing carbon fuelled, old, power plants, Water supply, Irrigation, Hydropower.

ERR unchanged from appraisal (17.5% to 17.9 %), but Financial Rate of Return unsatisfactory because only energy sales accounted for. All other benefits accounted as public goods and not reflected in the financial analysis.

Indirect Economic Impacts of Dams• Indirect economic effects

– derived from linkages between sectors of production directly affected by the project and the rest of the economy

– derived from expenditures by households out of extra income generated by project

• Multipliers – Summary measure of

relative importance of direct vs. indirect economic effects, expressed as a ratio of total to direct impacts

Findings

Multipliers of hydraulic infrastructure can be large – ranging between 1.4-2.4

Indirect economic impacts should be analyzed, quantified and taken into account in the ex-ante and ex-post evaluation of projects

Income distribution impacts can also be captured by using economy-wide models

Three Working Groups

Group 1: Case studies and literature review

Group 2: Economic and Financial aspects

Group 3: Long Term Planning

MPWS Group #3: Long Term Planning Life cycle of reservoirs (planning, engineering, construction,

operation, re-engineering)

Planning for the long term early on

Global warming, increasing hydrological variability, the role of storage, adaptive management.

The "economic pitfall" (inter-generation equity fund)

Life extension strategy and methods

Re-engineering for safety

Replacement of services 

Institutional challenges

MPWS Working Groups

Group 1: Case studies and literature review

Group 2: Economic and Financial aspects

Group 3: Long Term Planning

MPWS-Framework for Case Study collection and analysis

Projects designed and operated to serve two or more purposes

List of purposes deliverable by MPWS

Storage allocation

Decision Support Systems

Multipurpose timing

Dam modernization and re-engineering

Structural requirements

Economic Analysis

Your contribution will be highly appreciated

Thank you