Many rural communities in arid areas of the world make extensive use of perennial water
supplies retained within the sediment of a river channel. This naturally filtered water
provides for their basic subsistence. A general term applied to the abstraction of water
from river sediment is sand-abstraction.
Ephemeral and seasonal rivers primarily drain the dryland regions of the world. These
arid regions are typically subject to extensive environmental degradation with a
consequent high degree of surface erosion. As a result, many of the rivers have become
sand rivers, filled with copious amounts of sediment. Most arid areas are subject to
occasional rainstorms and flash floods that immediately drain to waterways and saturate
the sediment within the river channel. In larger rivers a perennial supply of water is
maintained within the sediment.
Despite a perceived potential for this water resource there has been little development of
any small-scale technology that is suitable for use at a basic rural level. A research and
study programme was instigated to assess fully, the potential of such a resource. Field
research was undertaken to characterise typical sand rivers and to assess the water storage
and water loss and retention factors within river sediment. A check list for identifying
possible sand-abstraction sites was devised. In the process of this study the advantages of
storing water in sand was fully appreciated and attention given to the development of
initially less suitable sites in serious water deficit areas. Systems for efficient abstraction
of water were reviewed and designs formulated for the fabrication of equipment to
mechanically draw water from river sediment. A series of well-screens, well-points,
infiltration galleries and caissons have been designed and initial tests have been
conducted under field conditions. Simple technology handpumps that it was considered
could be operated, maintained and repaired by rural communities using locally available
materials have been developed in conjunction with the abstraction equipment.
In consultation with rural people an analysis was made of the technical and sociological
requirements that are considered essential for the sustainability of technology suitable for
use by disadvantaged rural communities. Both practical and literature research has
indicated the latent possibility of this technology. Interaction has been maintained with
four communities throughout the research and development period and contributions and
indications received are that there is a need to develop such a water source with an
The conclusion from the work undertaken is that development of the technology is
worthwhile and that greater efforts should be made to promote it at a small-scale, rural
level. In addition the potential to provide clean water in arid regions from such a lowtechnology
application should be drawn to the attention of professional water engineers.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.