THE CONCEPT OF ’RESOURCE
OVEREXPLOITATION’
Some discussion of this concept is necessary here,
without getting hung-up over semantics. Clearly all
groundwater abstraction has an ‘impact’ – since it
diverts flow from elsewhere in an aquifer system and
reduces natural discharge. The real question is when
do such impacts become cumulatively significant
(Figure 1). It may appear appealing to use an
economic definition (ie: the costs of third-party
effects, longer-term environmental impacts and lost
resource opportunity exceeding short-term use
benefits) – but in practice it is often difficult to assess
the associated costs. Moreover, this does not consider
the 'efficiency versus equity issue' – given that lessdepleted
groundwater systems favour more equitable
access for the poor and often better protect ecological
interests. But maintaining groundwater stocks against
all depletion is rarely appropriate, especially in arid
regions where (given the long periodicity of major
recharge episodes) groundwater is critical for
mitigating the impacts of surface-water drought and
for providing time to allow transition to lower wateruse
economies to evolve.