The size of Watchem is approximately 112.9 square kilometres. It has 1 park covering nearly 0.2% of total area. The population of Watchem in 2011 was 455 people. By 2016 the population was 116 showing a population decline of 74.5% in the area during that time. The predominant age group in Watchem is 60-69 years. Households in Watchem are primarily couples with children and are likely to be repaying $300 - $449 per month on mortgage repayments. In general, people in Watchem work in a managers occupation. In 2011, 83.6% of the homes in Watchem were owner-occupied compared with 69.6% in 2016.