|Parapara Hydroelectric Scheme Homepage Aquatic Life Assessment.. page 10 contents|
behind. The Department of Conservation has recently expressed concern about the long-term viability of long-finned eel populations in New Zealand. Long finned eels are found throughout the Parapara. Both long finned eels and koaro would need to be provided with access through the gorge section of the Parapara to the dam. There is no evidence that the dam is itself affecting passage of those species that can negotiate the gorge. Given the steep gorge and cascades and falls throughout its length, the dam is itself no additional barrier to fish movement, at least for eels and koaro. The substantially larger numbers of fish in site two rather than site one, below the dam in the gorge section, suggests that the gorge itself is relatively inhospitable for fish, due to variable flows and many waterfalls. Fish passage is the primary issue for maintaining the fish populations upstream of the dam, however.
The single brown trout present confirms the lower river as being occasionally suitable for trout fishing, as there may also be limited whitebait fishing in the lower river. Neither of these activities would likely be affected by the proposed power scheme, as it is a run of the river proposal. There may be improved access for the public as far as the Glengyle Creek confluence if this was developed as part of the scheme.
Possible Effects of the Proposed Hydroelectric Power Scheme
The proposed hydroelectric power scheme would affect the river as fish habitat in the following ways. These can be divided into temporary or construction effects and permanent or ongoing effects.
The reinstatement of the dam water levels would have a minor effect on water levels in the impoundment upstream of the dam, but this would be very temporary and insignificant. Reinstatement of a channel through the existing swamp between the impounded waters upstream of the dam and the reinstated tunnel through to the penstock line would result in some loss of aquatic vegetation and release of fine sediment into the swamp and river. This sedimentation would take somewhat longer to settle, but would overall have relatively limited effect on the fishery value of the existing swamp, which is largely vegetated and holds considerable amounts of sediment. In other words, the swamp is presently of limited fisheries value. Some care would need to be taken with the disposal of any sediment or similar material to ensure as little as possible was deposited in the river or swamp, or was placed in any location where it might be mobilised during a heavy rainfall.
There may be some limited and localised effects of reinstating the tunnel and similarly the development of penstocks and channels in the upper parts of the Glengyle catchment. These are not likely to have any significant effects upon the fisheries values of the Glengyle, unless there are major or prolonged landslips or land disturbance in the affected area.
First, a high proportion of the river's flow upstream of the dam would be diverted into the headworks of the scheme. As stated above, the fish populations within the gorge and
Fish & Game New Zealand Nelson Marlborough Region Sports Fish and Game Bird Management ...p 10
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