 Following a parliamentary survey of the route by Charles McNiven, the bill received Royal Assent on 13 May 1791 and became an Act of Parliament for the construction of the canal, by which "the proprietors were empowered to purchase land for a breadth of 26 yards on level ground, and wider where required for cuttings or embankments." The Act allowed the company to raise £ 47,000, with shares of £ 100. The intention was that at Prestolee the route would divide into two branches (arms), with one branch towards Bolton and the other to Bury, but it would not, however, join the River Irwell. The proprietors were entitled to take water from any brooks within 1,000 yards (910 m) of the canal, or within 3 miles (4.8 km) of the canal summits at Bolton and Bury.
