Presentaci

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MANAGING DOMESTIC WATER IN THE METROPOLITAN
REGION OF BARCELONA A PARTICIPATORY,
AGENT-BASED APPROACH David Saurí Adolfo
López Mercè Capellades Mònica Rivera José Manuel
Galán
Universidad de Valladolid
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THE SITUATION OF THE DOMESTIC WATER SECTOR IN THE
METROPOLITAN REGION OF BARCELONA
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• The three most important issues at stake
• Water supply current and projected demand
  threatens current supplies
• Population change migration from the compact to
  the diffuse city
• Supply versus demand management

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The Metropolitan region of Barcelona
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The model Pressures, States, Impacts, Responses
PRESSURES STATE IMPACTS RESPONSES
NATURAL SYSTEM ?Climate change ?Increasing uncertainty in water supplies ?Increase in the frequency of drought periods ?Increase water supply  (external sources) ?Decrease water demand ?or a combination of both
TECHNICAL SYSTEM ?Increase in system efficiency (general levelhousehold level) ?Insufficient regional and municipal water supply networks   ?General non-availability of domestic water saving technology ?Leakages   ?Higher domestic consumption ?Increase and improve surface water networks   ?Slow installation of water saving technology in new households (not required by law)
SOCIO-ECONOMIC SYSTEM ?Population structure ?Migration ?Change in land use ?Increase in welfare ?Increase in domestic water demand in the diffuse city   ?Stabilization or decrease of water demand in the compact city ?Chances of water restrictions   ?Decrease in water quality ? Large-scale water transfer (Ebro, Rhône) ?Behavioural change (campaigns for water conservation)  ?Prices and taxes (block tariffs)
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Water stored in the Llobregat reservoirs
Capacity 139 Hm3
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Water stored in the Ter reservoirs
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Population change in the Metropolitan Region of
Barcelona 1950 2001
Source Institut dEstadística de Catalunya
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Urban land use in the MRB 1880-1999
New housing units by type, 1985-2000 (in )
Source Department of Land Use Policy and Public
Works. Generalitat de Catalunya.
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Evolution of the domestic water consumption
(liters/inhab/day)
Source ATLL
Delivery system losses () 1999
Source ATLL
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THE PARTICIPATORY PROCESS
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• AIMS AND SCOPE
• The most important objective is the discussion
  of water management alternatives through
  stakeholder participation.
• Creation of a stakeholder platform that
  incorporate a wide number of views on the
  domestic water sector. Selection of the
  participatory methods most suited to extract
  stakeholders goals, preferences and attitudes.
• The method of participation used is based on the
  development of a number of scenarios for water
  demand according to the opinions given by
  stakeholders in interwiews and group meetings.

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Composition of the Stakeholder platform
public organizations private companies civil
society
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• Scenario-building exercise
• Several meetings with the stakeholder platform
• Elaboration of three scenarios regarding the
  future of the domestic water sector in the study
  area.
• Scenarios were used as the basic input for the
  elaboration of the agent-based model. All
  scenarios have three basic components
• 1) Climate
• 2) Changes in population and type of housing
• 3) Demand management alternatives

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• Three scenarios for simulation
• Scenario A Residential mobility from the
  compact to the diffuse city continues and
  water conservation measures are introduced. The
  scenario has two variantsnormal climate
  conditions and extreme climate conditions. This
  scenario was considered as the more plausible
  by the stakeholders platform.
• Scenario B Residential mobility from the
  compact to the diffuse city continues without
  water conservation measures. The two variants
  (normal and extreme climate) also considered.
• c) Scenario C Residential mobility from the
  compact to the diffuse city stops, and no water
  conservation measures are introduced. The two
  variants (normal and extreme climate) also
  considered.

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THE AGENT-BASED MODEL
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Model description
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Escenario A perfil climático 1
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Escenario A perfil climático 2
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Escenario A perfil climático 3
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Escenario B resultados.
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Escenario C resultados
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• Main results of the simulation
• Scenario A continuation in the trend of
  residential mobility from the compact to the
  diffuse city and introduction water conservation
  measures. In this scenario, water supply is
  insufficient to absorb demand despite
  conservation. In normal climatic situations,
  emergency levels are not reached. However, they
  are reached in extreme climate conditions.
• Scenario B continuation in the trend of
  residential mobility without water conservation
  measures. Rapid rise of emergency situations that
  can only be solved through a substatial increase
  in water supply such a large scale transfer from
  the Ebro or Rhône rivers.
• Scenario C changes in residential mobility
  (migratory fluxes towards the diffuse city
  diminish) without water conservation measures.
  Emergency situation are not reached even under
  conditions of climatic stress.

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CONCLUSIONS   -Relevance of the urban form for
water planning and management (need of
integration of water planning with spatial
planning).   -Participatory process allowed for
the consideration of stakeholders concerns into
problem definition (elaboration of scenarios) and
ways to approach this problem (elaboration of the
agent-based model). To our knowledge, first
participatory exercise of this kind in the
area.   -Agent-based modelling provided an
alternative way to think about water issues in
the Barcelona region by integrating a number of
natural, technical and socioeconomic factors
(richer view, in our opinion, than that given by
traditional forecasting techniques).
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ALL DRESSED UP AND NOWHERE TO GO? (Possible
future avenues for research)   -Advance in the
understanding of water consumption behaviour at
the household level (vey important for improving
the ABM model)   -Advance in the understanding of
the effects of water policy (privatization of
municipal supplies, impact of prices and taxes,
etc.).   -Consolidate the stakeholder platform
for future assessment of water policy
alternatives, and improve the presence of some of
its members (only about two thirds of the
platform has participated actively in the
process).   -Enhance simulation to other parts of
the hydrological cycle (especially water quality)