IWRA Executive Office

OS1j IWRM: Sustainable management of complex water systems

abstract 202

Gaming with eutrophication : contribution to integrating water quantity and quality management at catchment level

Author(s): Lucie Clavel (1)(4), Raphaèle Ducrot(1)(3), Suzana Sendacz(2)
1. UMR G-EAU (Gestion de l’eau, acteurs usages) /CIRAD – Visiting scientist FUNCEME, Fundação Cearense de Meteorologia e Recursos Hídricos, Av Rui Barbosa, 1246, Aldeota, CEP 60 115-221 Fortaleza-CE(raphaele.ducrot@cirad.fr) 2. Instituto de Pesca, Secretaria de Agricultura do Estado de São Paulo, Av. Francisco Matarazzo, 455, 05001-900 São Paulo/SP/Brazil (sendacz@pesca.sp.gov.br) 3. IEA-USP - Av Prof Luciano Gualberto Travessa J 374 Terreo Cidade Universitária - 05508-900 São Paulo/SP Brasil 4. INRA //UMR 1248 - AGIR (Agrosystèmes et développement territorial) - B.P. 52627 Auzeville F 31326 Castanet Tolosan Cedex (lucie.clavel@toulouse.inra.fr)

Keyword(s): role playing game; integrated water management; eutrophication; water allocation; peri-urban catchment

Article:

Poster:

Session: OS1j IWRM: Sustainable management of complex water systems

AbstractThe Metropolitan Region of Sao Paulo (MRSP) hosts 18 million inhabitants. A complex system of 23

interconnected reservoirs was built to ensure its water supply. Half of the potable water produced for MRSP’s

population (35 m3/s) is imported from a neighbour catchment, the other half is produced within the Alto Tietê

catchment, where 99% of the population lives. Perimeters of land use restriction were defined to contain

uncontrolled urbanization, as domestic effluents were causing increasing eutrophication of some of these reservoirs.

In the 90’s catchment committees and sub committees were created to promote discussion between stakeholders

and develop catchment plans.

The committees are very well structured “on paper”. However, they are not

very well organised and face a lack of experience. The objective of this work was to design tools that would

strengthen their discussion capacities. The specific objective of the AguAloca process was to integrate the quality

issue and its relation to catchment management as a whole in these discussions.

The work was developed in

the Alto Tietê Cabeceiras sub-catchment, one of the 5 sub catchments of the Alto-Tietê. It contains 5 interconnected

dams, and presents competitive uses such as water supply, industry, effluent dilution and irrigated agriculture.
A

RPG was designed following a companion modelling approach (Etienne et al., 2003). It contains a friendly game-

board, a set of individual and collective rules and a computerized biophysical model.
The biophysical model is

used to simulate water allocation and quality processes at catchment level. It articulates 3 modules. A simplified

nutrient discharge model permits the estimation of land use nutrient exportation. An arc-node model simulates water

flows and associated nutrient charges from one point of the hydrographical network to another. The Vollenweider

model is used for simulating specific reservoir dynamics. The RPG allows players to make individual and collective

decisions related to water allocation and the management of its quality. Impacts of these decisions are then simulated

using the biophysical model. Specific indicators of the game are then updated and may influence player’s behaviour

(actions) in following rounds.

To introduce discussions on the management of water quality at a catchment

level, an issue that is rarely explicitly dealt with, four game sessions were implemented involving representatives of

basin committees and water and sanitation engineers. During the game session, the participants took advantage of the

water quality output of the biophysical model to test management alternatives such as rural sewage collection or

effluent dilution.

The biophysical model accelerated calculations of flows and eutrophication rates that were

then returned to the game board with explicit indicators of quantity and quality. Players could easily test decisions

impacting on qualitative water processes and visualize the simulation results directly on the game board that was

representing a friendly, virtual and simplified catchment. The Agualoca game proved its ability to turn complex water

processes understandable for a non totally initiated public.
This experience contributed to a better understanding

of multiple-use water management and also of joint management of water quality and quantity.

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Gaming with eutrophication : contribution to integrating water quantity and quality management at catchment level