1.4 demographic change is urbanisation a solution or a problem for improving sanitation? learning...
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1.4 Demographic Change
Is urbanisation a solution or a problem for improving sanitation?
Learning objectives: to gain insights about the role of demography in sanitation planning and implementation
Jan-Olof Drangert, Linköping University, Sweden
The Urban Sanitation Challenge
World population (in billions): 2000 2050 (estimate)
Total 6
Rural 3
Urban 3
3
6
Jan-Olof Drangert, Linköping University, Sweden
Thus, new housing on virgin land in new cities provides excellent opportunities for new sanitation options to fulfil
the Millennium Development Goals for sanitation
9.3
Population growth rates and the proportion living in informal settlements: means for the largest cities (%)
0
5
10
15
20
25
30
Africa Asia LA & C Oceania Europe
Informal settlementsPopulation growth/year
%
Source: UNDP & Unicef, 2003
LA & C = Latin America and the Caribbean
Treated waste-water
City council capacity to do its part
Source: UNDP & Unicef, 2003
%
0
10
20
30
40
50
60
70
80
90
Africa Asia LA & C America Europe
Proportion of wastewater being effectively treated
Evolution of the relationship between residents and utilities in Sweden
1970 1990subscriber customer
Supply of water
All water can be cleaned
All want to connect
Simple treatment plants
H2O-law
Price
Demand
Envir. law
Chemical society
Cannot treat all water at acceptable cost
partner
Time
Jan-Olof Drangert, Linköping University, Sweden
Demografic patterns are decisive: The growth-infrastructure hypotheses
Population
Time
transi-tion
transi-tion
Slow develop-ment of the infrastructure
Lowering portion or even absolute decrease of infrastructure
Rapid improvement
Jan-Olof Drangert, Linköping University, Sweden
How to manage sanitation arrangements?
Turn-key management where a utility (private or public) provides the service and the residents just pay the bill
Own-key management where single households or housing associations initiate, build and control, while they put to use available skills, materials, and other local resources
Turn-key Own-key
WC &sewerage
Dry urine-diverting toilet
Dug latrine Aqua privyJan-Olof Drangert. Linköping University, Sweden
A key question is about control, not degree of centralisation. Two extremes:
Septic tank
Example 1: Evolution of w&s in Kisumu town, Kenya
1963 200019501900
Turn-key
Own- key
Source: Drangert et al., 2002
350,000
200,000
300,000
100,000
50,000
Population
Indepen-dence
0
20
40
60
80
100
120
140
piped water
sewerage
wc
Norrköping
Example 2: Evolution of w&s in Norrköping, Sweden
Source: Drangert & Hallström, 2002
Norrköping(thousands)
First piped water
Town area expansion
Town area expansion
Town area expansion
Hypotheses on best management optionPopulation
transi-tion
transi-tion
own-key own-key own-key
Jan-Olof Drangert, Linköping University, Sweden
pro
po
rtio
ns Turn-key Turn-keyTurn-key
Time
Economic Development and Water Supply in a ' Secondary city'National GDP per person real with 0.88% and 2.15% per year trend lines
$0
$5,000
$10,000
$15,000
$20,000
$25,000
$30,000
$35,000
$40,000
Present low-income economies average GNI pc at PPP
Present lower middle-income
Present upper middle-income
High-inc
Water Closets becoming popular in capital cityNewly installed WCs discharging to ditches, Hagley Road
Ordure is emptied anywhere at nightfall; The city’s first public wash house opened in Kent StreetMind where you tread, Sir, for the children have been here'One third of city using unimproved pit latrines First sewage farm acquired
City trying to convert to bucket latrines as improvement'One in three artisan families still had to share external toilet with neighbours'45% households access bucket latrines (1 per 10 HHs) 15% using unimproved pit latrines;
Over half houses get WCs - most still outsideopen 'drainage [in one slum court] is so vile that the air seems positively putrid' 20% lacking a WC Still shared toilets for slums
Household toilets generally achieved
'Cost reflective tariffs' required for newly privatised providers (300 year sewer
replacement cycle?)
Source: Cranfield university, UK
Economic development and w&s in Cranfield, UK National GDP per person real with 0.88% and 2.15% per year trend lines
Evolution of indoor water taps in rural Sweden
1900 1950
100%10 Mil
17%
2000
50%
29%
63%
70%
10%
90%
Gradual improvement towards full coverage
BUT, what about the impact of urbanisation?
5 Mil
Jan-Olof Drangert, Linköping University, Sweden
Why do we often act as if we were only a few hundred million people on earth?
• Small farmers understand and practise reuse, but urban residents do not
• Ever more people live in big villages, towns and cities
• Most farmers have had access to chemical fertilisers this far
• Change comes with a cost
• But, there is also a saving; better food security
Local experience
global understanding
Jan-Olof Drangert, Linköping University, Sweden
However we still act as if we were a few hundred million people on earth