ing one of the worst droughts observed in the region
in the last 200 years. The consequences of drought have
been far reaching both for human consumptive uses and
for aquatic ecosystems, and serve to highlight several
important aspects of the nature of droughts, their
ecological impacts, and how humans respond to them.
Running water ecosystems are the dominant form of
freshwater ecosystem in Australia, yet, despite the high
frequency of drought we lack a basic understanding of
the consequences of long-term droughts (as distinct
from seasonal droughts) as an ecosystem disturbance,
and more is known about drought effects on flowing
than on standing waters. Drought is well defined and
characterised meteorologically, but hydrologically its
characterisation is equivocal. While drought severely
impacts natural aquatic ecosystems, its effects have
been and are exacerbated by direct and indirect anthropogenic modifications to streams and their catchments.
In streams the major impacts are the loss of water and
habitat availability, and the reduct