First, land and water managers (at all levels from national agencies to
individuals) are able to engage in risk and cost shifting rather than genuine
risk reduction. Risk shifting comes in many guises. It can obviously
take place within a river basin when, for example, upstream
water abstractors reduce their own water security risks by taking a disproportionate
share of available resources and leaving downstream
abstractors exposed to greater scarcity risks. Given the nature of water
as a hydrologically interconnected, multi-purpose resource such
upstream water security decisions often generate different forms of risk
for downstream populations by increasing the potential harms from
inadequately diluted pollution or by endangering downstream ecosystems.
In other cases water or land managers are able to make economic
decisions without considering the potential harms (the externality
costs) imposed on others. This obviously occurs when inadequate
expenditure on wastewater treatment results in the export of pollution
risk to all downstream water users, including flora and fauna, which
depend upon the quality of water flows. Other examples, include land
use decisions (deforestation or urban development) which magnify
downstream flood risks or decisions about risk mitigation technologies
which simply transfer risks to others. Coastal and flood plain communities
have, for instance, been able to improve their own defences and
in effect have simply shifted the risk to undefended areas. Indeed it has
long been argued that urban drainage schemes based on hard technologies
have not only shifted the risk but have considerably magnified
it by concentrating and speeding up flood flows.
In addition to spatial risk or cost shifting, it is also important to note
that risk can and has been shifted over time. The mining of groundwater
today will clearly affect the water security of future generations;
inadequate irrigation and drainage schemes which result in salinization
may impinge upon future food security; while ecosystem damage now
may critically reduce ecosystem services in the future