In the early 19th century, most of Cardiff was built on land overlaying gravel beds, which extended to the north and west of the populated area.

On the day before the bill was due to appear before the House of Commons committee, the company agreed to sell, for a price of £300,000, resulting in the corporation withdrawing their objections.

Two days before the final purchase, the company declined to accept the cheques, despite assurances from the banks that they would be honoured, and so the corporation elected to pay in gold.

[5] The corporation consulted John Taylor, one of the original directors and promoters of the Cardiff Waterworks Company, who had also been their Engineer, about the works at Ely.

Unable to decide the best way to proceed, they asked the water engineer John Frederick Bateman for advice in December 1881, and in June 1882 he confirmed that the Taff Fawr scheme was the best option.

[8] A bill for the Taff Fawr scheme was submitted to Parliament in November 1883, and a House of Commons committee considered it between 1 May and 20 May 1884, as there were 16 petitions against it, particularly from riparian landowners.

The corporation called on many of the major water engineers of the day to give evidence, including Bateman, Thomas Hawksley, James Mansergh, and George H. Hill.

B. Williams also gave evidence, as did the meteorologist George James Symonds, and although it cost £3,652 to fight their case, it was successful and the Cardiff Corporation Act 1884 (47 & 48 Vict.

The upper area covered 4,000 acres (1,600 ha) and required a compensation flow of 3 million imperial gallons (14 Ml) per day, under half of the total for the whole catchment.

[10] In order to facilitate the transport of materials to site, 6 miles (9.7 km) of standard gauge railway were built, connecting to the mainline near Cefn-coed-y-cymmer station.

Priestley oversaw the latter stages of construction at Beacons Reservoir, and a number of smaller projects, including a water tower and high-level service reservoir at Penylan, to allow the population of Rhymney, St Mellons and Penylan to benefit from a proper water supply, the construction of three more filter beds at Heath, and the expansion of the pipework within the town.

Thomas D Ridley of Cardiff and Middlesbrough was awarded a contract worth £10,115 for three more filter beds, and to facilitate the transport of materials to the site, a siding was constructed from the Rhymney Railway.

Work began on 5 April 1897, with sand and gravel for the filters coming from Bideford in Devon by ship to Cardiff, and then by rail into the site.

[16] The corporation's area of supply was extended to include St Fagans in 1902, and money was borrowed to fund a new service reservoir at Leckwith and extensions to the works at Rhiwbina, Cogan, and Heath.

A bypass was constructed near Llanishen viaduct, to enable water from the Taff Fawr pipeline to be routed directly to the filter beds at Heath, and a second supply for sanitary purposes was laid into the town.

[15] Consideration was given to increasing the size of the Llwyn-on Reservoir so that it could supply the compensation water for the whole catchment, 7.75 million imperial gallons (35.2 Ml) per day.

The project was expected to take six years from January 1911, but due to the onset of the First World War, HM Treasury ordered that work should cease in 1915.

Although he died in 1916, his cause was taken up by the engineer Robert Brodie, and after an appeal against the outcome of arbitration by the corporation, the House of Lords eventually ruled in favour of Nott.

Initially, the corporation used direct labour, and they constructed a small railway from the reservoir site to the bottom of the field, which was operational by November 1920.

The corporation employed Francois Cementation Company to make borings and carry out remedial work in 1926-1927 and finished the construction using direct labour.

No.3114 dating from 1918 was bought second hand from the Ministry of Munitions and subsequently worked on the Lake Vyrnwy pipeline contract for Liverpool Corporation Waterworks.

Between 1932 and 1937, it was used on the construction of Fernilee Reservoir for Stockport Corporation,[23] and is now preserved as part of the historic locomotive collection at the Vale of Rheidol Railway.

It was designed to hold 5,390 million imperial gallons (24,500 Ml), and is located in the valley of the Sôr Brook near Pontypool and the Royal Ordnance Factory at Glascoed.

The dam consists of an earth embankment, with a core of rolled clay, and it is filled by water pumped from an intake on the River Usk at Prioress Mill, Rhadyr.

[26] Faced with the fact that many towns suffered from outbreaks of typhus and cholera, the social reformer Edwin Chadwick had produced his report The Sanitary Conditions of the Labouring Classes in Britain in 1842.

His report caught the public imagination,[27] and in 1847, Lord Morpeth, an ally of Chadwick, introduced a bill into Parliament that would have required local authorities to ensure that all houses in towns had a proper water supply, and a drainage system to take away waste.

Towns and districts could request an inspection from the Board of Health, which then gave them powers which would otherwise have required a local act of Parliament, which was a costly process.

As required by the Act, one-tenth of the ratepayers had to request the Board of Health to carry out an inspection, which was performed by Thomas Webster Rammell.

[30] Henry James Paine, Cardiff's Officer of Health, reported 15 deaths from cholera in August 1854, although he thought the source might have been foreign ships, since six of the casualties were seamen, and the rest were closely associated with them.

Welsh Water built a new sewage treatment works on reclaimed land just to the east of the original outfall at Tremorfa, costing £118 million.