Groundwater use in developing cities: policy issues arising from current trends

Groundwater use in developing cities: policy issues arising from current trends

Stephen D. Foster & Ricardo Hirata &

Ken W. F. Howard

Keywords Groundwater supplies . Urban development . Urban infrastructure . Private groundwater use

Context for policy analysis and denition

Growing importance of urban groundwater useThe objective of this essay is to promote dialogue on important policy issues for urban planning and development arising from increased dependence on groundwater for water-supply provision in developing cities. There is much indirect evidence (although no comprehensive data) to substantiate this trend, which is occurring in response to population growth, increasing per capita water use, higher ambient temperatures and reduced security of river intakes (due to quality degradation and climate change) having been facilitated by the modest cost of water wells and the fact that aquifers lie within a wells length of users! (Foster et al. 1998).

Where urban centres are underlain and/or surrounded by high-yielding aquifers, this has allowed water utilities to expand mains water-supply incrementally at modest capital costusually resulting in better mains water-service levels, lower water-supply prices and less private in-situ use. However, there are rarely sufcient ground-

water resources within urban areas themselves to satisfy municipal water-supply demands and resource sustainability (both quantity and quality) will often become an issue.

Growth in urban groundwater use is not restricted to cities with ready access to high-yielding aquifers but also widely occurs where the utility water supply is imported from considerable distance from a major surface water source. Here, private in-situ water-well construction has often increased rapidly as a result of poor (present or historic) municipal water-service levels and/or high water-supply prices. For example (Foster et al. 2010):

& In Peninsular India, water well use for urban residen

tial self-supply is ubiquitous in the face of very poor utility water services (often 1-in-24 hours or less) and greatly reduces dependence on expensive tankered water supplies.

& In Brazil many cities experienced major private water-

well drilling 1520 years ago, in response to water-supply crises during extended drought, but such water wells continue because they provide a lower-cost water supply.

& In Sub-Saharan Africa, despite much higher unit costs

of drilling, water wells (for direct water collection or reticulation to standposts) are widely the fastest growing source...