This research was done to investigate appropriate water harvesting structures that can increase
the water availability and recharge to the groundwater system in Kanye and Molepolole areas. In
this study, geological, geophysical and hydrogeological methods were employed. The Kanye
region is underlain by igneous rocks that are non-conformably overlain by a thick sequence of
metasedimentary rocks deposited between 2.9 to 2.0 Ga. The mean annual rainfall of Kanye area
is 466.17 mm, and the groundwater recharge varies from 1.03 % to 5.70 % of the mean annual
rainfall of the area. Molepolole is located on the southern edge of the Karoo West Central
Kalahari Sub-Basin and is underlain by strata of the Karoo Supergroup. The mean annual rainfall
of the area is 423.64 mm, and the groundwater recharge varies from 0.09 % to 3.14 % of the
mean annual rainfall of the area. The three major geological formations that are water-bearing in
Kanye area are chert breccia, dolomite and the Waterberg Sandstone. The aquifer types are
dominantly consisting of multilayer unconfined-confined and multilayer confined aquifers types.
The aquifers in the Molepolole and its surroundings are Lebung group (Ntane sandstone) and the
Upper Ecca (Boritse Formation) and Middle Ecca (Kweneng Formation) sandstones. The
Lebung aquifer occurs only to the northeast of this part of the study area and appears to be
significantly controlled by structures. The Ecca aquifer occurs throughout Molepolole and its
surroundings areas and constitutes the principal aquifer. The aquifer types are mainly confined
aquifers. In Kanye region, with the exceptions of some trace elements such as Cr, As, Mn, Fe,
Cd, Pb and Ni, all major cations and anions, and trace elements such as Zn and Cu fall within the
standards of BOBS prescribed for domestic use. In Molepolole and its surroundings, with the
exceptions of some trace elements such as Cd and Pb, all major cations and anions, and trace
elements such as Fe, Mn, Cu, Ni, Zn, As and Cr fall within the standards of BOBS prescribed for
domestic use. The quality of groundwater is suitable for irrigation in both study areas. However,
the potential of alkali and magnesium hazards that could arise as a result of continues uses of the
groundwater for irrigation purpose should be given serious attention. Recommended water
harvesting structures varies on the basis of the respective aquifer types in the studied areas. In
Kanye stone bund is recommended in all water contributing areas or recharge zones of the
catchments and sub catchments in all over Kanye area. Deep trenches, percolation pond and
check dams are recommended in the middle section of all the catchments and sub catchments in
all over Kanye area where multilayer unconfined-confined aquifer system are found. Sand dam is recommended in the middle section of all the catchments and sub catchments in all over Kanye
area where multilayer unconfined-confined and multilayer confined aquifer systems are found.
Stone bund with trench is recommended in in water contributing areas or recharge zones of the
catchments and sub catchments in all over Molepolole area. Gabion check dams are
recommended in the rivers of Gamoleele, Molepolole, Mankgwenyane and Mokgopetsane that
drains the southern parts of Molepolole area southward to Metsimotlhaba river. Gabion check
dams are also recommended in the rivers of Gamoleele, Mankgwenyane and Mokgopetsane. In
the major intermittent streams in the watersheds of Molepolole area that drains the eastern and
southeastern parts of the area southeastward to Notwane river construction of gabion check dams
are recommended. In the watersheds of all these rivers, gully stabilization or gully treatment is
also recommended. The fossil valleys in the west and northwest of Molepolole area are favorable
sites specifically for sand dams and this water harvesting structure is recommended in these parts
of the study area. Detail specification of each structure to the specific area should be made by
considering other important parameters (peak flow analyses, stream dimension measurements,
contouring, etc.) that are vital to the design of each structure where the structure is constructed.