Difference between revisions of "Urban groundwater in Africa"

From Earthwise
Jump to: navigation, search
[checked revision][checked revision]
Line 4: Line 4:
  
  
Groundwater is becoming more and more important in urban areas - towns and cities - in Africa. There is rapid urbanisation all across Africa: the UN estimates that by 2035, 50% of all Africans will live in urban settlements. With urban populations and urban areas growing all the time, the demand for water in urban areas is also growing. Within the overall pattern of urbanisation in Africa, much of the growth is concentrated in towns and smaller urban centres, not only in big cities. Much of the urban population growth is in low income groups. Both of these factors present additional challenges for water supply and sanitation in general, and for groundwater resource development and protection in particular.  
+
Groundwater is becoming more and more important in urban areas - towns and cities - in Africa. There is rapid urbanisation all across Africa: the UN estimates that by 2035, 50% of all Africans will live in urban settlements. Already in 2017, an estimated 250 million people (40% of the total population) live in urban centres across sub-Saharan Africa. This urban growth is driving a huge growth in demand for water in urban areas, but the lack of adequate management of household and industrial waste in many expanding urban centres is a growing concern. Within the overall pattern of urbanisation in Africa, much of the growth is concentrated in towns and smaller urban centres, not only in big cities. Much of the urban population growth is in low income groups. Both of these factors present additional challenges for water supply and sanitation in general, and for groundwater resource development and protection in particular.  
  
 
Groundwater has much to offer in urban areas in Africa: it is a resource that urban dwellers, planners and managers can't afford to overlook. But to continue being useful, groundwater must also be protected from pollution and over-abstraction.  
 
Groundwater has much to offer in urban areas in Africa: it is a resource that urban dwellers, planners and managers can't afford to overlook. But to continue being useful, groundwater must also be protected from pollution and over-abstraction.  
Line 10: Line 10:
 
This page provides some background on the issue of urban groundwater and links to more information.  
 
This page provides some background on the issue of urban groundwater and links to more information.  
  
===Overviews of urban groundwater in Africa===
+
==Overviews of urban groundwater in Africa==
  
 
The following list is of some recent reports and other documents that give a useful overview of the issues around urban groundwater in Africa.
 
The following list is of some recent reports and other documents that give a useful overview of the issues around urban groundwater in Africa.
Line 28: Line 28:
 
:-Taylor RG and Barrett M. 1999. [https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/30368/1/203.pdf Urban groundwater development in sub-Saharan Africa]. In: Pickford J. (ed). Integrated development for water supply and sanitation: Proceedings of the 25th WEDC International Conference, Addis Ababa, Ethiopia, 30 August-2 September 1999, pp.203-207.
 
:-Taylor RG and Barrett M. 1999. [https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/30368/1/203.pdf Urban groundwater development in sub-Saharan Africa]. In: Pickford J. (ed). Integrated development for water supply and sanitation: Proceedings of the 25th WEDC International Conference, Addis Ababa, Ethiopia, 30 August-2 September 1999, pp.203-207.
  
 +
==Key issues in urban groundwater in Africa==
  
 +
===Groundwater pollution / contamination===
  
 +
Groundwater-fed water supplies - such as boreholes and wells - in urban areas in much of Africa are at high risk of contamination. Many towns and cities do not have effective sewerage networks or waste water treatment facilities, and unregulated disposal of sewage, industrial and other solid and liquid wastes is widespread. The rapid growth in urban areas has led to the proliferation of unimproved sanitation provision largely through the use of pit latrines, which are often little more than a hole in the ground, and are often in very close proximity to wells and springs that are used for domestic water supply. There are also many other sources of groundwater pollution including: large and small factories; leaking sewer pipes; and even improved on-site sanitation facilities such as septic tank soakaways.
  
 +
Shallower groundwater is at higher risk of pollution than deeper groundwater, because the travel times for pollutants to shallow groundwater are much shorter. Because of this, groundwater from shallow sources, such as hand-dug wells, is more at risk. However, deeper groundwater can also be at risk, depending on the type and amount of pollution and the local hydrogeological conditions, and so even well-constructed deep municipal or private boreholes can be affected.
 +
 +
A wide range of pollutants can affect groundwater in urban areas. Microbiological contamination is an important water quality challenge. Faecal waste is the largest source of contamination in urban (and rural) groundwater in Africa, in particular where there is high-density housing with poor and/or inadequate sanitation facilities and treatment of faecal waste - as in many rapidly growing towns.
  
  

Revision as of 12:07, 21 March 2019

Africa Groundwater Atlas >> Resource pages >> Urban groundwater in Africa

  This page is being developed. Please check back soon for more content.


Groundwater is becoming more and more important in urban areas - towns and cities - in Africa. There is rapid urbanisation all across Africa: the UN estimates that by 2035, 50% of all Africans will live in urban settlements. Already in 2017, an estimated 250 million people (40% of the total population) live in urban centres across sub-Saharan Africa. This urban growth is driving a huge growth in demand for water in urban areas, but the lack of adequate management of household and industrial waste in many expanding urban centres is a growing concern. Within the overall pattern of urbanisation in Africa, much of the growth is concentrated in towns and smaller urban centres, not only in big cities. Much of the urban population growth is in low income groups. Both of these factors present additional challenges for water supply and sanitation in general, and for groundwater resource development and protection in particular.

Groundwater has much to offer in urban areas in Africa: it is a resource that urban dwellers, planners and managers can't afford to overlook. But to continue being useful, groundwater must also be protected from pollution and over-abstraction.

This page provides some background on the issue of urban groundwater and links to more information.

Overviews of urban groundwater in Africa

The following list is of some recent reports and other documents that give a useful overview of the issues around urban groundwater in Africa.

- Foster S, Bousquet A and Furey S. 2018. Urban groundwater use in Tropical Africa – a key factor in enhancing water security?. Water Policy 20(5), 982-994. Doi: 10.2166/wp.2018.056
- Lapworth DJ, Nkhuwa DCW, Okotto-Okotto J, Pedley S, Stuart ME, Tijani MN and Wright J. 2017. Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health. Hydrogeology Journal, 25 (4). 1093-1116. doi: 10.1007/s10040-016-1516-6
- Foster SSD. 2017. Urban groundwater dependency in tropical Africa: a scoping study of pro-poor options. UPGro Working Paper (March 2017).
- Lapworth D. 2017. Urban groundwater and groundwater quality in Africa. Presentation at IAH/GeolSoc 2017 Ineson Meeting, London, UK, 25 October 2017.
- Sorensen et al. 2015. Emerging contaminants in urban groundwater sources in Africa. Water Research 72, 51-63. Doi: 10.1016/j.watres.2014.08.002.
- Adelana M, Tamiru A, Nkuwa DCW, Tindimugaya C and Oga MS. 2008. [1]. In book: In S.M.A. Adelana & A.M. MacDonald (eds), Applied groundwater studies in Africa, Chapter: 14, Publisher: Taylor & Francis London, Editors: S.M.A. Adelana & A.M. MacDonald, pp.231-260. doi:10.1201/9780203889497.pt3
-Taylor RG and Barrett M. 1999. Urban groundwater development in sub-Saharan Africa. In: Pickford J. (ed). Integrated development for water supply and sanitation: Proceedings of the 25th WEDC International Conference, Addis Ababa, Ethiopia, 30 August-2 September 1999, pp.203-207.

Key issues in urban groundwater in Africa

Groundwater pollution / contamination

Groundwater-fed water supplies - such as boreholes and wells - in urban areas in much of Africa are at high risk of contamination. Many towns and cities do not have effective sewerage networks or waste water treatment facilities, and unregulated disposal of sewage, industrial and other solid and liquid wastes is widespread. The rapid growth in urban areas has led to the proliferation of unimproved sanitation provision largely through the use of pit latrines, which are often little more than a hole in the ground, and are often in very close proximity to wells and springs that are used for domestic water supply. There are also many other sources of groundwater pollution including: large and small factories; leaking sewer pipes; and even improved on-site sanitation facilities such as septic tank soakaways.

Shallower groundwater is at higher risk of pollution than deeper groundwater, because the travel times for pollutants to shallow groundwater are much shorter. Because of this, groundwater from shallow sources, such as hand-dug wells, is more at risk. However, deeper groundwater can also be at risk, depending on the type and amount of pollution and the local hydrogeological conditions, and so even well-constructed deep municipal or private boreholes can be affected.

A wide range of pollutants can affect groundwater in urban areas. Microbiological contamination is an important water quality challenge. Faecal waste is the largest source of contamination in urban (and rural) groundwater in Africa, in particular where there is high-density housing with poor and/or inadequate sanitation facilities and treatment of faecal waste - as in many rapidly growing towns.


Return to: Africa Groundwater Atlas >> Resource pages