Wind turbine driven pumps in conjunction with approximately one mechanical opening per year
Description of option
The use of two Windflow 500 wind turbines (manufactured in Christchurch) was proposed to generate electricity to power three pumps, each with a capacity of 5 m³/s. The water would enter an intake over a semi circular weir where it would be sucked up through three 1m diameter reinforced concrete pipes. The water would be pumped over the Kaitorete Barrier and discharged through a single large culvert designed to reduce outflow velocities to below 1 m/s.
Opening, closing, and lake level control description
Pumps would operate continuously, but one or two mechanical opening would still be required when water levels increase significantly during winter.
below 50 cumecs
Wind turbines and pumps would need regular maintenance.
$2.5 million for Windflow turbine option (Duke et al., 2002). $4.1 million for a series of 11 turbines operating smaller pumps (Crouch et al., 2002). $46,000 for one artificial opening per year.
Fish passage benefit rating
Potential running impacts or benefits