| 1887 | The Waihi Gold Mining Company was incorporated in London on 7 December 1887 |
| 1888 | Waihi Battery construction started on Union Hill in early 1888 to process ore from the Union, Rosemont, Amaranth, and the smaller Trio, Nelson, and Winner claims. Built first ore roasting kilns on the Hauraki field. Dry crushing until 1902. Mill Stream dammed and the Mill Race constructed? Tailings saved in tailings pits? |
| 1890 | Martha Company's mine and plant purchased by Thomas H. Russell for £3,000, and transferred to the Waihi Gold Mining Co. for a payment of £6,000 and £20,000 in paid up shares. |
| 1893 | The Cassel Company purchased the Waihi Company's accumulated heap of tailings, estimated at from 25,000 to 30,000 tons. Under a Deed of Assignment dated 17 May 1893 they paid £5000 for these and all tailings produced by pan-amalgamation up to 15 November 1893, and were given a maximum of three years in which to complete the processing. A water-race was constructed to bring in water from the creek receiving water from the swamp, and also that flowing from the adit-level of the Waihi Mine. The plant is situated near the river, and below the place where the tailings are deposited. |
| 1894 | The Cassel plant was able to start on the Waihi tailings in March. The Union-Waihi Gold Mining Company was formed to work the Union-Rosemont-Amaranth section. Sinking of the New shaft commenced (New No.1). The Waihi Battery converted to the cyanide process in May. |
| 1895 | Another 30 stamps were added to the Waihi Battery, giving a total of 90. Cassel Co. recovers bullion to £25,000. |
| 1896 | The Silverton battery commenced operating on 4 April 1896; railway and locomotive installed for hauling the ore a mile and a half to the battery, which was expanded to forty stamps. |
| 1898 | Union-Waihi Co. acquires the Silverton Claim. The Union-Waihi Gold-mining Company have acquired all the mining properties held by the Waihi-Silverton Gold-mining Company, together with its battery of forty stamp-heads, tramway, &c. The battery is now being thoroughly overhauled and repaired, preparatory to commencing crushing. The process to be adopted is to be wet crushing. Renaming it the Union Battery. |
| 1900 | Union-Waihi: extensive surface-works have been done in laying tram-roads on the flat and incline-trams to connect the mine with the battery. About this time the New Central Hotel was built. |
| 1901 | The Waihi G.M.C. takes over the Union-Waihi Company's properties (including the Silverton {Union} battery). |
| 1902 | Mining stops on Union Hill. The Union mill of 40 stamps started crushing for the Waihi Co. in September (ie Martha ore) |
| 1904 | In consequence of the extension of the Mine workings and their encroachment on the Superintendent's house, it became necessary to remove and re-erect it. This work has been carried out, the new site chosen being conveniently near to the Waihi Mill |
| 1905 | As the flume conveying the water from the “Cassels” race across the tailings pit to the low pressure race to Waihi Mill was of insufficient capacity, it has been replaced by a larger one. |
| 1906 | May 17. Waihi population in 1900 was 3,812, and had gone up this census 2,274 to 6,086. August 24, 1906. "The Waihi Grand Junction Gold Company's 40 stamper mill is now in full swing." A small " special site " of half-an-acre for a quarry near Waihi Mill was taken up [Speak's? - E]. Photograph shows existence of a single tennis court. |
| 1907 | About this time the municipal swimming baths in Kenny Street were constructed. |
| 1909 | At the Waihi Battery two ferro-concrete agitator-vats, 13ft. diameter, 55 ft. high, have been erected (four more in 1910). |
| 1911 | The Union mill was closed down in February |
| 1912 | Waihi strike. Waihi Mill has not been re-started since the strike. We are arranging to crush and treat the ore now on hand and then make some slight alterations, in order to treat about 16,000 tons of sand tailing which was stored near the mill before tube mills were in use. |
| 1913 | The only work at Waihi Mill—apart from the treatment of tailings—was the crushing and treatment of 622 tons of ore from the Mill hoppers, and cleaning up values about the Mill. |
| 1914 | Early in 1914 the company's hydro-electric power-installation at Horahora commissioned. |
| 1920 | Possible opening of new tennis court. |
| 1921 | The New Central Hotel is dismantled and moved to Rotorua. |
| 1922 | New Tennis Club formed. |
| 1960s | Waihi Borough tip at Kenny Street established. Mill Stream diverted into Speak’s Quarry. |
| Late 1970s | Waihi Borough tip at Kenny Street closed and capped in early 1980s. |
| 1986 | Mill Stream lowered under conveyor and channelled into Speak’s Quarry by Waihi Gold. |
| 2002 | Waihi Walkways construct Mill Stream Walkway. |
| 2007 | Waihi Walkways construct Mill Stream Walkway extension. |