Groundwater development is generally part of a larger water management and supply strategy, in which
other supply options, for instance from surface water, exist also. Groundwater does have significant
advantages over other supply options:
Development of offshore groundwater becomes particularly interesting when cheap, shallow aquifers onshore
have become unsustainable, polluted, or otherwise cause negative environmental effects. In many cases
- in addition to exploring more unconventional onshore, groundwater occurrences - only expensive
alternatives remain, such as elaborate pipeline & storage facilities or seawater desalination.
Depending on several key parameters, of which groundwater quality & depth, and distance offshore
are the most important, one can develop offshore paleogroundwater and realize a significant cost-saving.
In addition there are significant operational and environmental benefits too.
- Lower overall capital & operational cost than seawater desalination
- Capacity increase of existing water sources through blending
- Possibility of direct use quality
(compared to surface water and seawater)
- Protected from surface pollution
- Little solute load & chemically stable
- Constant temperature
(compared to seawater desalination)
- Less brines disposal
- Less chemical usage
- Less energy required
The documented occurrences of offshore groundwater are enormous and not to be exploited rapidly,
while environmental problems related to onshore overexploitation of shallow groundwater, notably land subsidence
and coastal salinization, are avoided.
Offshore (Paleo)Groundwater extending to > 50 km offshore in Surinam
The water’s origin can be both fossil and recent and qualities range from potable (< 500 mg/l TDS)
to saline. Obviously the latter component is not of interest, but the associated volumes of fresh to
lightly brackish groundwater are, especially offshore, still far greater than that of most conventional
and shallower onshore aquifers.
