While the WR&CC's line was under construction, mining interests in Ohai united to present a petition that the government acquire the WR&CC line and extend it into Ohai. Unfortunately, the arguments in favour of this proposal were presented to a parliamentary committee in 1914 just as World War I broke out and further consideration of the proposal was postponed. However, later that year the Local Railways Act was passed and, despite objections from the Nightcaps Coal Company and others in Nightcaps, the Ohai Railway District was declared on 4 May 1916. The declaration of this District included a condition that the Ohai Railway Board had to acquire the WR&CC line before constructing any new railway. The case for acquisition went to a compensation court, and, upon paying the sum of 19,862 pounds 6 shillings and 6 pence, the Ohai Railway Board took control of the WR&CC line on 22 June 1917.