Part 1 - Palmerston North City Council

gemconsulting
The Mangaotane Stream will be realigned through part of Pari Reserve. The realigned route will see the
stream entering the reserve, as it does now, and taking a right hand turn before joining the river just
upstream of the snub groyne. Some vegetation will be cleared to enable this re‐alignment however it is
noted that the vegetation within this part of the reserve is predominately willows and poplars. The realignment
is unlikely to create any adverse effect on the reserve with the stream appearing to have
followed several differing routes to the river in the past and vegetation expected to quickly re‐establish.
Rule 15.5.5.1 Policies
This rule addresses ongoing maintenance of flood protection structures within the zone and contains six
specific policies as follows:
(a)
(b)
(c)
(d)
(e)
(f)
To avoid, remedy or mitigate any adverse effects associated with maintenance work on the
environment.
To ensure that any excavation of land is minimised and any adverse effects are remedied or
mitigated upon the completion of the works.
To ensure that any adverse effects associated with the use of land for the storage and/or
disposal of materials associated with the maintenance of flood protection works are remedied or
mitigated upon the completion of the work.
To assess the appropriateness and necessity for the removal or destruction of any tree associated
with any maintenance work.
To ensure that the removal or destruction of vegetation is remedied or mitigated, through the
restoration of the affected area and the re‐vegetation of the site.
To recognise the positive effects of flood protection works.
The rock lining and associated works will become assets of the Lower Manawatu Scheme. To ensure
operational effectiveness, maintenance will be undertaken if required, however this is not expected to
occur particularly often. As stated, the rock lining is designed to be ‘self‐healing’ with higher rocks slipping
into place should lower level rocks become displaced. In general any maintenance will consist of a truck
and excavator accessing the top of the rock lining to top up any depressions where rocks have slipped
down.
More significant maintenance would only be required if the lining or bed armouring is damaged during a
major flood event. This may necessitate the stockpiling of rock, further machinery being present, and
various excavations required to repair any damage.
Only a small portion of the rock lining is located within the Conservation and Amenity Zone. During any
maintenance, public access to the rock lining will need to be closed to ensure safety is maintained. Access
to the lining will be through the Hargreaves land and maintenance carried out from the top of the lining
itself, thereby minimising effects on the environment and avoiding disruptions to the City side of the river.
It is likely that a stockpile of rock will be kept near the lining for maintenance purposes. This will be located
on the land between the rock lining and the snub groyne and be well screened from view by the existing
vegetation. As an access track is to be maintained to the lining it is not expected that any further
vegetation would require removal to accommodate any maintenance works.
Rule 15.5.7.2 Policies
This rule contains six additional policies as follows:
(a)
(b)
To avoid, remedy or mitigate the visual effects of flood protection works on the amenity values
of the Conservation and Amenity Zone and adjoining residential areas.
To avoid, remedy or mitigate any adverse effects associated with the development and
construction of flood protection works on the scenic, scientific, heritage, and conservation and
amenity values of the Conservation and Amenity Zone.
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