Peel Inlet and Harvey Estuary System Management Strategy ...

EPA Report on the Peel-Harvey Progress and Compliance Report, 2003
system continues to find a new equilibrium as a result of the altered flushing regime,
and after there have been additional years of larger flows and nutrient delivery.
Of increasing concern to the local community are continuing blooms of Nodularia and
other cyanophytes (blue-green algae) in the lower reaches of the Serpentine River. In
recent years, there have also been localised accumulations of macro-algae in the
southern portion of the Harvey Estuary. This means that although the system has
improved, it is still in a fragile condition and reductions in nutrient loads from the
catchment, as required by the Minister’s Conditions set in 1989, are still needed.
Monitoring of the three main rivers has shown that there appears to have been small
reductions in nutrient loads for the Serpentine and Harvey Rivers. Although these
apparent reductions are encouraging, there is still considerable improvement required
before the target nutrient loads are met. Based on monitoring since 1993, the average
annual P load in the Serpentine River (measured at Dog Hill gauging station) still
requires a 72% reduction and the average annual P load in the Harvey River (measured
at Clifton Park gauging station) requires a 21% reduction to meet the total phosphorus
(TP) targets.
The Murray River appears to be performing within its target for TP, although being
unregulated this river is subject to extreme floods (like February 2000), and a different
pattern may well emerge when these data are considered.
Statutory targets for TP runoff should be further divided to include scaled targets for the
Serpentine River (at Dog Hill), the Murray River (at Pinjarra) and the Harvey River (at
Clifton Park), thus providing a nested series of catchment targets for different scales of
application which will better support compliance testing. It would be useful for the
nested catchment targets to be incorporated into the EPP.
The community’s growing expectation for continual improvement, and the continuing
degraded condition of the lower Serpentine River, mean that current targets for estuarine
water quality and catchment runoff should be maintained and reviewed again in 10
years. This would allow for a longer series of flow years on which to base a system-wide
performance audit. Additionally it is recommended that other measures of system health
for the estuary, rivers, streams, wetlands and the Peel-Harvey catchment be explored.
Given the degree of community interest in the Peel-Harvey Estuary System, it is
recommended that the EPA should commence extensive public consultation to obtain the
community’s views on the environmental quality it desires and meaningful measures of
system health for the estuaries and the catchment”.
9. WHERE TO FROM HERE?
The Expert Review Committee expressed the view, and this is endorsed by the EPA, that
the EPA has an important, central and ongoing role to play in natural resource
management across all areas of the State, in ensuring that the environment is fully taken
into account and that proposed management actions will indeed be sufficient to deliver
environmental protection and restoration outcomes.
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