The reservoir, fed by the Allan Water (formed where the Skelfhill and Priesthaugh Burns meet, and joining the Teviot at Newmill), has long been the sight of prosperity. The whole area is dense with ancient earthworks, forts, and burial mounds, indicating a rich history of population by earlier peoples. In 1858, a bronze-age axe was unearthed on the banks of the Allan and donated to the museum. Where Allan Water meets the Teviot, there stands the ruins of the 16th century Allanhaugh Toor (also known as the Allanmouth Tower).
In 1864, work began on the Allan Water Reservoir – a gravitational water supply, from a site on the Allan situated above Hawick. The call for a cleaner town water supply had began over a decade earlier, when in 1849 a devastating cholera outbreak claimed the lives of 197 townsfolk. Completed in 1865, to the tune of £7000, the reservoir’s sluice was officially opened by the Duke of Buccleuch in a ‘turning-on’ ceremony, attended by several thousand people. The day of the ceremony was designated a public holiday, and the procession led under a floral arch (spanning the width of the High Street at the Town Hall) by Cornet David Scott, Provost George Wilson, Town Clerk Thomas Purdom, and Right- and Left-Hand Men Thomas Hislop and Adam Hart.