[3] Just north of the lake, the river opens into a broad floodplain, through which channels have been dug to support irrigated farming.

[2] The river's inlet to Lake Naivasha is cloaked with Papyrus, other sedges and Typha.

[4] The Gilgil and the much larger Malewa are the main sources of water for Lake Naivasha.

Gregory discovered an old settlement on the Gilgil River with obsidian stone flake tools and rough pottery, predating the Iron Age.

Tools included skin scrapers, borers and small knives.