Ecological, sociological and economic implications of sediment management in reservoirs

Since long time ago, sediment management has been recognized as a major problem in water resources projects. The water storage capacity of reservoirs progressively reduces by sedimentation, unless costly and complex mitigation measures are adopted in the upstream reaches and watershed of the dammed river and/or at the dam site. However, usually the sedimentation management is faced with special or exclusive attention to what is regarded as the utmost objective to be attained. That is the structural safety of the dam itself and the restoration of the lost capacity of the reservoir.

As a matter of facts, many other aspects concerning sediments have to be considered and analyzed. Indeed sedimentation management involves, among others, ecological, sociological and economic implications. It suffices mentioning the strong opposition by people living downstream a reservoir, against sediments bypassing (sluicing, venting, flushing through dam's outlets), due to the high sediment and pollutant concentration in the discharged water and due to possible negative effects downstream on hydraulic infrastructures, on fishing and on other recreational activities. Again, the mechanical removal of sediments' deposits and their disposal far from the reservoir may be extremely costly and have a negative impact on the sediment balance of the entire river system, down to the beaches near to the river mouth. On the other hand, reducing the sediment input by soil conservation in watershed surface (usually obtained by a substantial reduction of the arable land and/or by modifying the local agronomy) may present, in some countries, serious economic and sociological consequences that virtually prevent its application as a mitigation measure.

The management of sediments intercepted in reservoirs requires the combined action of various disciplines and can benefit from experiences gained in different countries. With this in mind, four leading water-related international associations (IAHR, ICOLD, IAHS and IRTCES) founded the International Coordinating Committee On Reservoir Sedimentation, ICCORES, in 1992 in Bergamo, Italy. A formal agreement of cooperation was subsequently signed in 1993 by the Secretaries General of each one of the four associations. Later on, two more organizations (IAWQ and IWRA) joined the Committee. During the following years, several initiatives were taken by ICCORES in its field of competence, very often under the auspices of UNESCO; for instance, the International Workshop of St. Petersburg, Russia (May 1994) and the International Conference of Fort Collins, Colorado, US (September 1996). Furthermore several meetings held in various countries have been attended with the participation of the ICCORES representatives. All these activities were mostly performed within the framework of the V Phase of the UNESCO International Hydrological Programme (IHP-V in Project 2.2 “Sedimentation processes in reservoirs and deltas”).

The next workshop on “Ecological, sociological and economic implications of sediment management in reservoirs” reflects the most recent activity of ICCORES. The format of the workshop would be a relatively small meeting to allow a discussion with no more than 20 invited speakers, each one delivering a lecture on a well–defined topic, substantially based on case–studies; among them, the representatives of the associations constituting ICCORES.

All contributions will be then published to provide professionals with suggestions and ideas to be (discriminately) applied to specific problems. Contributions will be complemented by discussions and comments by attending speakers and participants.

The targeted venue will be the archaeological site of Paestum, the old Greek city on the coast South of Naples, Italy. The workshop will be hosted by ISIDE Consortium, an organization operating on dam and land safety and monitoring.

The period Monday the 8^th, Tuesday the 9^th and Wednesday the 10^th of April 2002.

A Scientific Committee has been set up to coordinate the contributions and advice about the publication of the proceedings. Members and institution are:

Giampaolo Di Silvio........................................................................................................... ICCORES

Morando Dolcetta................................................................................................................... ITCOLD

Giovanni Fiore................................................................................................... Italian Dams Service

Fabio Rossi....................................................................................................... University of Salerno

Andras Szöllösi–Nagy......................................................................................................... UNESCO

Lucio Ubertini................................................................................................................. CNR–GNDCI

Sam Y. Wang.............................................................................................. University of Mississippi

Hsieh Wen Shen.............................................................................................. University of Berkeley

Rodney White............................................................................................................................... IAHR

Selim Yalin............................................................................................................. Queen's University

Tan Ying................................................................................................................................... IRTCES

The Local Organizing Committee is as following reported:

Paolo Bonaldi................................................................................................................ ERGA S.P.A.

Franco Chirico............................................................................................................................ ISIDE

Frédéric Fournier................................................................................................................. UNESCO

Paolo Paoli.................................................................................................................................. ISIDE

Alberto Peano................................................................................................. ENEL HYDRO S.P.A.

Mario Scagnetto........................................................................................................................... CNR

Four different thematic areas have been selected:

1–Sediment management strategies

2–Environmental impact and mitigation

3–Legal framework and social response

4–Economic aspects

The international experts invited to contribute to the workshop are listed in the Annex.

Further information are available by contacting:

Consorzio Gestione Centro ISIDE

Località Piano della Rocca

84060 Prignano Cilento

Salerno Italy

Mario Scagnetto

Tel.: +39 339 5831289

Fax: +39 041 988871

E–mail: mhcify.bh@usa.net

Paolo Paoli

Tel.: +39 02 9248527

Fax: +39 02 9235807

E–mail: hdkpa@tin.it

ANNEX – LIST OF INVITED SPEAKERS, INSTITUTIONS AND TOPICS

SPEAKER	INSTITUTION	COVERED TOPIC
Session 1: Sediment management strategies
Bruno Molino	University of Basilicata, Italy	Monitoring and restoring of artificial reservoirs
Alessandro Palmieri	The World Bank, United Nations	Strategic alternatives for the sustainable management of reservoirs
Manfred Spreafico	Federal Office of Environment, Forest and Landscape, Switzerland	An overview of problems related to reservoir sedimentation in Switzerland and solution strategies
Des Walling	University of Exeter, United Kingdom	Identifying suspended sediment sources in river basins as a basis for developing sediment management strategies.
Zhao–Yin Wang	IRTCES	Dynamical impact of erosion control on reforestation of west China
Session 2: Environmental impact and mitigation
Nikolay Alekseevskiy	Moscow State University, Russia	The ecological impact of changes of the sediment transport downstream dams in Russia
Gerrit Basson	University of Stellenbosch, South Africa	Control of the impacts of a dam on the downstream river morphology through flood flushing and the release of artificial floods
Wojciech Froehlich	International Committee on Continental Erosion, IAHS	Impact of anthropogenic sediment source of reservoirs sedimentation in the Polish Carpathians (with D. Walling)
Masanori Michiue	Tottori University Koyama, Japan	Environmental problems due to sedimentation in a reservoir
Alain Petitjean	Fluvial Hydraulics Section, IAHR	Flushing and emptying operations of reservoirs and their consequences on the environment. Application to Grangent reservoir on the Loire river, France
Session 3: Legal framework and social response
George Annandale	Engineering and Hydrosystems Inc., USA	Social, environmental and economic issues surrounding dam removal initiatives in the United States of America
Stevan Bruk	International Hydrological Programme UNESCO	Sediment research and social response: the Danube upstream from the Iron Gates Dam (with M. Mladenovic)
Stefano Burchi	Development Law Service, FAO	Legal implications of reservoir sedimentation in different countries
Massimo Cadeddu	ITCOLD	Siltation of reservoirs: the Italian case (with G. Fanelli, A. Linari and M. Lucignani).
Helmut Scheuerlein	Geophysical Hydraulics Division, IAHR	Sediment problems initiated through unexpected reactions of the public upon reservoir operation strategies (examples from North Africa, Bavaria and Austria)
Session 4: Economic aspects
Emil Gölz	Federal Institute of Hydrology, Germany	Bedload management - a tool for stabilising degrading river beds
Rollin Hotchkiss	Washington State University, USA ICCORES	Applications of hydrosuction sediment removal systems in the United States (with R. Huffaker)
Ray Huffaker	Washington State University, USA	Economic analysis of reservoir sedimentation (with R. Hotchkiss)
Mohamed Moattassem	National Water Research Center, Egypt	The Aswan Dam