Rhymney had been completed a connection would then be made to Fochriw. It was understood that a branch main would be run over the mountain from Pontlottyn, the contour of the service enabling this to be done, which would give an efficient supply to all the houses in Fochriw, but not those at Penybank. The reservoir at Rhymney Bridge was completed and mains laid through the valley, and it was not understood why the branch pipes were not laid.. The Council decided to ask the Company to lay on the service forthwith.
In December 1907 the Rhymney and Aber Gas and Water Company proposed to put up a new water tank at Fochriw which would supply the district in a sufficient manner. However, there was little hope for an improved service, but the completion of the tank would increase the pressure, and therefore improve the supply, but during April 1908 the quantity of water was still inadequate.(Location of water tank foundations)
The district's water supply in 1908 was provided to a limited extent by the Council and mainly by the Rhymney and Aber Valleys Gas and Water Company. As early as 1909, all the authorities in the Rhymney Valley began discussing the formation of a Water Board. Agreement was difficult to obtain and the negotiations were protracted. A Bill was presented to Parliament in 1911 seeking powers to establish a Water Board, to acquire the Gas and Water Company's water undertaking and to build a reservoir in the Taf Fechan Valley, north of Merthyr Tydfil. The objections to the Bill were many and strong and it failed to reach the statute book.
In April 1917 the situation had not improved which led to letters being sent to the Council from the Fochriw Lodge of the Miners' Federation complaining of the scarcity of water. They stated that water had to be carried from the pits, and people had to wait by the hour for water. If a fire occurred at Fochriw, they did not know what their plight would be, and there were valuable houses - even in Fochriw
In 1920, however, a second Bill was placed before Parliament for the formation of the Rhymney Valley Water Board and at the same time another Bill was presented setting up the Taf Fechan Water Supply Board of which the Rhymney Valley Water Board was to be a constituent member. Both Bills were passed in 1921 and in 1928 the Taf Fechan reservoir, having a capacity of 3,400 million gallons, was completed and became the main source of the water supply of the district.