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
THE SITUATION OF THE
DOMESTIC WATER SECTOR IN
THE METROPOLITAN REGION
OF BARCELONA
The three most important issues at stake:
1) Water supply: current and projected demand
threatens current supplies
2) Population change: migration from the compact to
the diffuse city
3) Supply versus demand management
The Metropolitan region of Barcelona
2
4
3
1
5
6
13
11
8
14
15
Cities greater than 50.000 inhab. in 1996
7
9
0
1. Mataró
2. Granollers
3. Sabadell
4.Terrassa
5.Rubí
6.Cerdanyola
7.Sant Boi de Llobregat
8.Cornellà de Llobregat
Barcelona county
12
10
24Km
Rest of the MRB
9. Viladecans
10. Prat del Llobregat, el
11. Barcelona
12. Hospitalet de Llobregat, l’
13. Santa Coloma de Gramanet
14. Badalona
15. Sant Adrià de Besòs
The model: Pressures, States, Impacts, Responses
PRESSURES
NATURAL
SYSTEM
TECHNICAL
SYSTEM
STATE
IMPACTS
RESPONSES
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
Increase in system
efficiency (general
level+household level)
Insufficient regional
and municipal water
supply networks
Leakages
Increase and improve
surface water networks
General nonavailability of domestic
water saving technology
SOCIOECONOMIC
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
Higher domestic
consumption
Chances of water
restrictions
Decrease in water
quality
Slow installation of
water saving technology in
new households (not
required by law)
 Large-scale water
transfer (Ebro, Rhône)
Behavioural change
(campaigns for water
conservation)
Prices and taxes
(block tariffs)
Llo bregat system
year
dro ught warning level
oct-01
oct-00
oct-99
oct-98
oct-97
oct-96
oct-95
oct-94
oct-93
oct-92
oct-91
oct-90
oct-89
oct-88
oct-87
oct-86
oct-85
oct-84
oct-83
oct-82
oct-81
oct-80
Hm
3
Water stored in the Llobregat reservoirs
Capacity: 139 Hm3
160
140
120
100
80
60
40
20
0
Water stored in the Ter reservoirs
3
Capacity: 402 Hm
Population change in the Metropolitan Region of Barcelona 1950 – 2001
1950
Barcelona county
1960
1970
1975
1981
1986
1996
2001
1,446,170 1,809,197 2,315,096 2,460,619 2,511,592 2,376,609 2,302,137 2,131,378 2,105,302
Cities > 50,000 inhab.
215,385
343,289
635,593
784,327
849,064
Rest of MRB
304,736
414,247
615,273
774,767
878,220
Total MRB
1991
848,490
885,332
886,198
915,461
1,004,428 1,076,953 1,210,472 1,369,640
1,966,291 2,566,733 3,565,962 4,019,713 4,238,876 4,229,527 4,264,422 4,228,048 4,390,403
Source: Institut d’Estadística de Catalunya
3.000.000
2.500.000
2.000.000
1.500.000
1.000.000
500.000
0
1950 1960 1970 1975
Barcelonès
1981 1986 1991 1996 2001
Ciutats >50,000 hab.
Resta de RMB
Urban land use in the MRB 1880-1999
Source: A. Serratosa
New housing units by type, 1985-2000 (in %)
Barcelona county
Single Units
3,76
Condominiums Apartament Blocks
12,46
83,50
Rest of the MRB
18,70
18,84
61,91
0,54
Total MRB
16,60
17,94
64,96
0,50
Source: Department of Land Use Policy and Public Works. Generalitat de Catalunya.
No Data
0,27
Evolution of the domestic water consumption (liters/inhab/day)
1994
1996
1997 1998
1999
Barcelona county
123,28 129,18 129,39 130,15 126,75
Cities >50,000 inhab.
115,8 125,35 128,16 129,96 130,32
Rest of MRB
193,99 179,24 189,32 193,6 194,77
Total MRB
136,75 140,13 143,25 145,54 144,09
Source: ATLL
Delivery system losses (%) 1999
Delivery system
losses
Barcelona county
22.57
Cities >50,000 inhab.
18.37
Rest of MRB
21.38
Total MRB
21.21
Source: ATLL
THE PARTICIPATORY PROCESS
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.
Composition of the Stakeholder platform:
Decision maker
ACA
(Catalan water agency)
Metropolitan
Region of
Barcelona
public organizations
private companies
civil society
Executor
Influencer
ATLL
ROCA
(Regional water (Manufacturer of domestic
supply network)
water technology )
AGBAR
APCE
(Municipal water
(Association of builders
supply company) and real estate developers)
CONFAVC
(Confederation of
neighborhood and
community groups)
OCUC
(Consumer association)
Alternativa Verda
(green political party)
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
Three scenarios for simulation
a)
Scenario “A”: Residential mobility from the “compact” to the
“diffuse” city continues and water conservation measures are
introduced. The scenario has two variants:”normal” climate
conditions and “extreme” climate conditions. This scenario
was considered as the “more plausible” by the stakeholders
platform.
b)
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.
THE AGENT-BASED MODEL
Model description
Emergency
Social
Module
Government
Module
Demand
Module
Territorial
Module
Supply
Module
Climate
Module
Infrastructure
Module
Market
Module
Stakeholders
Module
Escenario A: perfil climático 1
Escenario A: perfil climático 2
Escenario A: perfil climático 3
Escenario B: resultados.
Escenario C: resultados
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.
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).
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)