% 530 words
% Discuss the importance of mitigation in EIA and possible measures
% to address the potential impacts of the proposed development

\section{Mitigation}

In the process of applied EIA, actions relating to the avoidance,
minimisation or reduction of project impacts as well as the
compensation for an impact on a particular component of the
environment are referred to as mitigation measures.  Keeping in mind
that EIA is a decision-making tool that includes weighing negative and
positive impacts against each other, mitigation may also include
actions that promote or increase the beneficial effects of a proposed
development \parencite{mitigation}. As proposed activities can cause
adverse effects far from the project site that would not normally be
addressed in a cost benefit analysis, mitigation is also a way by
which the proponents are made to take responsibility for adverse
effects and pay for measures to reduce or avoid them altogether,
rather than externalising the costs to affected communities or the
general public \parencite{rmit}.  This issue remains a challenge with
higher-order social impacts that are difficult to quantify.

Any mitigation measure must be matched by a monitoring measure to
ensure that an activity designed to reduce an adverse impact has the
intended effect and does not introduce any additional adverse effects
that would require mitigation themselves.  While it is feasible to
monitor quantifiable quality indicators for resources in the
biophysical environment (e.g. nutrient load of a river, water
temperature, air pollution, generation of greenhouse gases), there is
no standard method to proactively measure the many potential
unintended side-effects of a mitigation
measure \parencite[compare][]{mitigation}. As a mitigation measure and
associated monitoring can be very expensive, the project planners have
to consider alternatives to proposed activities early on in the
planning process.  The requirement for listing mitigation measures in
the EIA process hence encourages an inclusive, open approach to
development.


\subsection{Measures to address potential impacts of the proposed project}

% http://www.niwa.co.nz/our-science/freshwater/tools/kaitiaki_tools/impacts/sediment/mitigation
The temporary effects of construction work on the river, such as
sedimentation from earthworks, could be minimised by establishing
permanent vegetated riparian buffers or by using temporary filtering
devices such as hay bales or mesh fences to reduce the amount of
sediment polluting the water \parencite{niwa-freshwater}.  A
permanent vegetated buffer zone would not only be a minimisation
measure for the effects of construction work, but also reduce the
impacts due to leakage from dairy farms.

% http://www.niwa.co.nz/our-science/freshwater/tools/kaitiaki_tools/land-use/water-take,-dam,-divert2/water-take/mitigation

The adverse effects of water take cannot easily be mitigated unless
the abstracted amount is reduced.  The cumulative allocations of water
in the region should stay well above the maximum amount that may be
taken while maintaining minimum flows that are required to sustain
aquatic ecosystems and existing fish and invertebrate populations.  A
new factory should be designed to use less water; this could be
accomplished by reusing water where reuse does not have sanitary
implications (e.g. using grey water for cooling). To prevent serious
problems associated with temporary over-allocation (such as hostile
rises in water temperatures due to low flow or water levels), key
indicators near the factory site need to be monitored constantly.

%http://www.niwa.co.nz/our-science/freshwater/tools/kaitiaki_tools/land-use/meat-processing/impacts/chemical-contaminates-and-meat-and-dairy-processing/mitigation

The generation of wastewater is closely linked to the amount of water
that is abstracted from the river. Reducing water consumption would
equally reduce the amount of wastewater to be discharged. When the
adverse effects on river water outweigh the effects of energy
consumption, wastewater could be treated internally to allow its
reuse. Treating wastewater before discharge is also a way to reduce
the contamination of waterways with excess nutrients, harmful
bacteria, as well as organic and inorganic compounds.  An alternative
to discharging wastewater in rivers is the application to soils, such
as pasture or farm land, thereby recycling nutrients.  Dependent on
the amount of nutrients removed by plants or other means, nutrients
can be lost to groundwater or be washed into open water bodies where
they accelerate the process of
eutrophication \parencite{chemical}. Hence, this attempt at
minimisation will itself be in need of an impact assessment.

%     Facilitate up and downstream passage for fish migration where these may be blocked at the water intake - using ramps, ladders and spillways.
%     Divert fish away from intake screens and outlet pipes.
% 
% Riparian vegetation - maintaining fish habitat
% 
%     Maintain, restore, and enhance riparian vegetation and wetland areas, which serve as spawning grounds and shoaling habitats for mahinga kai. Wetland areas and native planting also create refuge areas, lower water temperatures, and provide a food source of invertebrates for mahinga kai species.
