The size of Willowmavin is approximately 57.3 square kilometres. It has 3 parks covering nearly 3.8% of total area. The population of Willowmavin in 2011 was 499 people. By 2016 the population was 218 showing a population decline of 56.3% in the area during that time. The predominant age group in Willowmavin is 50-59 years. Households in Willowmavin are primarily childless couples and are likely to be repaying $1400 - $1799 per month on mortgage repayments. In general, people in Willowmavin work in a professional occupation. In 2011, 87.4% of the homes in Willowmavin were owner-occupied compared with 91.1% in 2016.