The enabling Act had imposed time restrictions on completing the reservoir, and in 1866 the company went back to Parliament for a second Act, which extended the time limits. The contract for construction was given to McGuire, at a cost of £19,900 and work began on the project on 11 September 1869. The directors decided that no payment would be made until the contractor had spent £2,000. Three months later, McGuire was in financial trouble, and the company decided to complete the work themselves. McGuire was hired to oversee the work, and paid a salary of £200 per year. Construction of the reservoir was aided by a narrow gauge railway, some in length, built to bring stone from Moot Law Quarry. A locomotive to work the line was obtained from Black, Hawthorn & Co. of Gateshead. The workers were affected by an outbreak of smallpox, and there were some problems with settlement of the western embankment. Because the company were desperately short of water, they started impounding water in the reservoir in December 1870, when the work done thus far meant that it could safely hold , nearly half of its capacity when it was completed in 1872. Surplus plant was sold off in October 1871, the locomotive was sold in spring 1872, and another sale took place in November 1972. When the work was finished, McGuire was paid his £2,000. Water from the reservoir was conveyed to Whittle Dean using the aqueduct and tunnel which had been completed in 1859.