regime of waterways in the study region. Studies in Australia have
suggested a wide range of acceptable environmental flows, based
on percentages of various flow regimes, generally ranging from 66%
to 90%, although the percentage figures have been found to be
inadequate to depict the seasonal variation inflows (Arthington
et al., 2006). Such availability factors have to be applied in the
calculation of the potentially available water for human use, so that
the WSF indices can be calculated for different types of land use
within the study area catchment as shown in Table 1. We do
acknowledge that extraction based on a particular percentage may
not truly reflect the amount of water that can be extracted from the
system. The water system is being replenished at all points
downstream from the initial extraction, and further water may be
extracted downstream without affecting environmental flows and
following the precautionary principle. Thus, the methodology
proposed here results in a highly conservative estimate of available
water.