MANAGING DOMESTIC WATER IN THE

METROPOLITAN REGION OF BARCELONA:

A PARTICIPATORY, AGENT-BASED APPROACH

David SauríAdolfo LópezMercè CapelladesMònica RiveraJosé Manuel Galán

Universidad de ValladolidUniversidad 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

Barcelona county

Rest of the MRB

1

2

34

5

6

7

9

8

10

13

12

1115

14

1. Mataró 9. Viladecans2. Granollers 10. Prat del Llobregat, el3. Sabadell 11. Barcelona 4.Terrassa 12. Hospitalet de Llobregat, l’5.Rubí 13. Santa Coloma de Gramanet6.Cerdanyola 14. Badalona7.Sant Boi de Llobregat 15. Sant Adrià de Besòs8.Cornellà de Llobregat

0 24Km

Cities greater than 50.000 inhab. in 1996

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 level+household 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)

The model: Pressures, States, Impacts, Responses

0

20

40

60

80

100

120

140

160

oct-80oct-81oct-82oct-83oct-84oct-85oct-86oct-87oct-88oct-89oct-90oct-91oct-92oct-93oct-94oct-95oct-96oct-97oct-98oct-99oct-00oct-01

year

Hm

3

Llobregat system drought warning level

Water stored in the Llobregat reservoirsCapacity: 139 Hm3

0

50

100

150

200

250

300

350

400

450

year

Ter system drought warning level

Water stored in the Ter reservoirs

Capacity: 402 Hm3

1950 1960 1970 1975 1981 1986 1991 1996 2001

Barcelona county 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. 215,385 343,289 635,593 784,327 849,064 848,490 885,332 886,198 915,461

Rest of MRB 304,736 414,247 615,273 774,767 878,220 1,004,428 1,076,953 1,210,472 1,369,640

Total MRB 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

Population change in the Metropolitan Region of Barcelona 1950 – 2001

Source: Institut d’Estadística de Catalunya

0

500.000

1.000.000

1.500.000

2.000.000

2.500.000

3.000.000

1950 1960 1970 1975 1981 1986 1991 1996 2001

Barcelonès Ciutats >50,000 hab. Resta de RMB

Source: A. Serratosa

Single Units Condominiums Apartament Blocks No Data Barcelona county 3,76 12,46 83,50 0,27

Rest of the MRB 18,70 18,84 61,91 0,54

Total MRB 16,60 17,94 64,96 0,50

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.

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

Evolution of the domestic water consumption (liters/inhab/day)

Delivery system

losses

Barcelona county 22.57

Cities >50,000 inhab. 18.37

Rest of MRB 21.38

Total MRB 21.21

Delivery system losses (%) 1999

Source: ATLL

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.

public organizations private companiescivil society

Decision maker

Executor Influencer

ACA (Catalan water agency)

ATLL (Regional water supply network)

ROCA (Manufacturer of domestic

water technology ) AGBAR

(Municipal water supply company)

APCE (Association of builders

and real estate developers) CONFAVC

(Confederation of neighborhood and

community groups) OCUC

(Consumer association)

Metropolitan Region of Barcelona

Alternativa Verda (green political party)

Composition of the Stakeholder platform:

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

Market Module

Government Module

Emergency

Infrastructure Module

Supply Module

Social Module

Demand Module

Territorial Module

Stakeholders Module

Climate Module

Model description

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)