Using groundwater for hydro electric power generation

Abstract

Controlled groundwater abstraction could be used to offset the effects of drought by augmenting river discharge for power generation during times of low natural flows, such as occurred in New Zealand during the winter of 1992. Augmenting river discharge with groundwater reduces the impact of a drought by spreading its effect over the recovery time of the aquifer. Groundwater could be introduced as an operational component for hydro generation in various ways. Fast-recovery aquifers might be operated as part of a normal daily hydro electric water storage and release. Existing hydro lakes might have their storage capacity increased by extending horizontal bores into the country from the lake shorelines, or by diverting any lake spillage onto artificial recharge zones. Water from deep pumped bores in vertical transmissive fault or shatter zones could augment mountain rivers for power generation. Flows might be augmented in low-relief regions by extensive fields of standard pumped bores. New kinds of hydro scheme that would allow power generation from sites where ecological or physical constraints prevent the usual forms of hydro development may be feasible. New Zealand localities for possible operational use of groundwater include the Mackenzie Basin and associated headwaters, the Volcanic Plateau, the Taupo region, and Westland. Small stand-alone groundwater power schemes may be possible in Campbell Island, the Chatham Islands, Great Barrier Island and Stewart Island.