The size of Back Valley is approximately 59.4 square kilometres. The population of Back Valley in 2011 was 732 people. By 2016 the population was 151 showing a population decline of 79.4% in the area during that time. The predominant age group in Back Valley is 60-69 years. Households in Back Valley are primarily childless couples and are likely to be repaying $2400 - $2999 per month on mortgage repayments. In general, people in Back Valley work in a managers occupation. In 2011, 75% of the homes in Back Valley were owner-occupied compared with 87.1% in 2016.