P.W.F. Weyer, a former hawker, who lost cattle in an attack by the Boers during the Anglo-Boer War, was said to have started the Darlington farm in the Jansenville district. He always said that the Boers had shot his animals in the Bedrogsfontein Pass.

Darlington had previously been home to Dr Reginald Koettlitz, who accompanied Captain Robert Falcon Scott on his first Antarctic expedition as senior medical officer. Some say that the doctor was blamed when some of the men of the expedition contracted scurvy and that this led him to come to South Africa to settle in the Karoo. He was not the only famous man to have contact with this farm and dam. The first chairman of the irrigation board responsible for the building of the dam was none other than Sir Percy Fitzpatrick, author of Jock of the Bushveld.

Weyer settled on Darlington in the fertile Sundays River Valley in 1905 and planted fruit orchards and vineyards. Later a hotel, post office, shop, smithy, house and several outbuildings were established on the farm. All this disappeared under the waters of Lake Mentz (Darlington Dam) when it was established in 1922. In 1924, Weyer was awarded £27 000 compensation.

Lake Mentz’s construction commenced in 1918, and was completed in 1924. As had been envisaged from the start, the capacity of the lake became progressively reduced by silting. The wall was raised by 1,5 metres which had the effect of restoring the capacity. The accumulation of silt had by 1946 again reduced the capacity. In 1949 the wall was raised a further 5,8 metres. When the servitude proceedings came before the Water Court it was agreed that nothing further in the future could be done for Lake Mentz by way of increasing its storage capacity.

Following the raising of the wall by 5,8 metres in 1949, Weyer’s successor, Bertram Henderson, was granted just under £40 000.

Even the name of the dam has a good story attached to it. According to local legend the then minister of land affairs, Colonel Hendrik Mentz, who had granted permission for the building of the dam, was not exactly a popular fellow, so when it was suggested that the dam be named after him, some irate person loudly exclaimed: “Oh, damn Mentz!”, to which he received a polite reply, “No, no, just Lake Mentz, will do!”

In the 1990s the ‘lake’ was renamed the Darlington Dam.

Today, Darlington Dam has been incorporated into the Addo Elephant National Park, adding to the attraction for tourists to the Park.