Hauâuru mâ raki Wind Farm is a large facility planned for the west coast of the upper North Island of New Zealand. As the wind farm will be adjacent to a major migratory shorebird flyway, 3 years were spent gaining an understanding of the possible mortality. Both radar and observers were used to gain data for use in the Band Model for providing a likely range of mortality estimates. An expert team from the Government's Department of Conservation, the local government and the company determined the potential range of measures for use in the model. A consent condition under the requirements of the Resource Management Act 1991 requires that the energy company obtain 3 years of data on breeding performance of one Endangered and one At Risk migratory shorebird species considered most susceptible to mortality from the proposed turbines. These data are required prior to any construction and is to be followed after construction of the wind farm begins with 5 years of further monitoring in conjunction with a pest control program that is estimated to enhance breeding output. The measure of additional breeding adults from this enhanced breeding is required to at least match the measures of turbine mortality. The pest control program is predicted to enhance breeding of these and other Endangered species such that there will be a significant biodiversity gain as a result of the wind farm.