Southdown sheep no longer economical and smaller flocks averaged only 135 ewes apiece. The use of artificial fertilizers had gained ground, and the combine-drill, which sowed grain seeds and fertilizer together, rendered close-folding by sheep unnecessary. Gradually surrendering to basic arable farming changes, the Southdown became largely a grassland breed. During the interwar years, the United Kingdom was known for farm animal breeding, and pedigreed Southdowns were still being exported to most parts of the world, especially New Zealand. In 1937, the number of exported Southdowns reached 459 head. During the Great Depression, a severe and prolonged fall in the prices of
Southdown Power Station River at full capacity. Apart from generating 170 MW of electricity for the wider Auckland area, Southdown also provided steam to the local industrial area near the station. At full capacity, the station could provide of steam per hour, piped from the station to consumers at pressures of . In the 2008 - 2009 financial year, Might River Power reported 249,407 tonnes of carbon dioxide emissions from Southdown. In March 2015, Mighty River Power announced that it would decommission Southdown and sell the plant overseas. Southdown Power Station Southdown Power Station was a natural gas-fired combined cycle gas turbine cogeneration