November 25, 1937. Vaal-Hartz Irrigation Scheme: Construction of the Hartz Canal, north of Pokwani. The scene is near the end of the canal, for just north of here it will meet the irrigable Hartz basin, a portion of which perhaps is visible at the top of the picture beyond the railroad. Note the tunnel which will lead water through the hill. 6400 feet. 06:00.