upstream of the dam are dependent upon access through the gorge for their continued maintenance. Some small flows through the gorge from the dam would therefore be required to attract and maintain fish movement through the gorge and to the upper river. Such flows would be supplemented by any additional flows from tributaries entering the gorge, and also from any flows in the Parapara greater than the capacity of the headraces and penstocks, which would need to pass over the dam and down the gorge.

The proposed scheme would undoubtedly reduce the total fish habitat available in the gorge reach between the dam and the Glengyle Creek or the tailrace of the proposed scheme. As stated above, however, this habitat is somewhat limited, since the gorge is of very limited fisheries value. Relatively few koaro and long-finned eels were found at site 1 below the dam, yet both these species were common upstream of the dam. A small water flow through the gorge would not reduce the amount of pool habitat available for any migratory or river resident fish, since pools can be supplemented by relatively small flows. Riffle and cascade habitat under normal flow conditions would be reduced, however.

The Pupu Hydro Scheme in the Waikoropupu River catchment of the Takaka River takes all the flow of Campbell's Creek into its headrace. This is a similar configuration to that proposed for the Parapara, albeit on a somewhat smaller scale. There is no continuous minimum flow below the headrace diversion to the point where the tailrace discharges back into Campbell's Creek immediately upstream of the Waikoropupu, except for the minor flow contribution from tributaries into the dewatered reach. Despite this, the excess flow during freshes and minor contributions from small tributaries seems sufficient to enable a healthy population of koaro and long-finned eels upstream of the headrace diversion. I am therefore confident that a small flow through the gorge from the dam, plus the contribution from gorge tributaries and from freshes in the Parapara River, would be sufficient to enable passage for eels and koaro to the dam and upstream.

With repair of the dam, water levels in the Parapara River upstream of the dam would be elevated by about a metre. This would likely be beneficial for fish populations in the swamp area at least, as there would be proportionally more water. There would be a negligible effect on habitat in the river for other fish species.

The proposal is for a continuously flowing and generating run of the river power scheme. If water storage was built in and the scheme was operated on a peak power demand basis, there would be fluctuating flows downstream of the power station. This would cause effects to the lower Parapara River that has not been contemplated in this assessment.

Seasonal high river flows have prevented access for fisheries investigation into much of the gorge between the dam and the Glengyle River confluence. When conditions are suitable, the lower gorge and probably the lower Glengyle River would be worth investigating for their fisheries.

Fish & Game New Zealand Nelson Marlborough Region Sports Fish and Game Bird Management ...p11