With a catchment area of 345 sq. miles, the Tutaekuri River rises on the western and southern faces of the Kaweka Range (highest point, Kaweka, 5,594 ft) and flows south-eastwards to enter the sea 4 miles south of Napier. It has one major tributary, the Mangaone River. Although the headwater area is composed of hard greywacke rocks and the river bed contains greywacke shingle, the bulk of the drainage area is Wanganuian (Pliocene and Lower Pleistocene) mudstones, sandstones, and limestones. Floodwaters of this river are therefore rather muddy from the suspended fine sediment eroded from the country to the east of the Black Birch Range. Early in the period of European settlement, the Tutaekuri River flowed north across the Ahuriri Plains through the present Marewa and Onekawa areas of Napier into the Ahuriri Lagoon and out to sea through a cut at Westshore.
The present outlet at Clive, common both to the Ngaruroro and to the Tutaekuri Rivers, is the product of river-control work since the Napier earthquake of 1931. Periodic intense rainfalls have caused severe flooding by the Tutaekuri River. In 1867 Clive Square in Napier was flooded and the Waitangi River bridge carried away. In 1897 the river rose to such an extent that parts of Napier were flooded to a depth of 4 ft and floodwaters flowed through the township of Taradale. In 1917 floodwaters from the river rose 6 in. higher and Meeanee, Taradale, Greenmeadows, and Napier were flooded. Other floods occurred in 1893, 1924, 1927, 1929, 1932 (four times), 1933, 1934, and 1938. River-control work now appears to have successfully contained the river, although in 1963 during the Tangoio floods the river rose to within 3 in. of the top of the stop-banks at Awatoto before it cut a separate direct outlet to the sea. The minimum measured flow was 82 cusecs in 1946 and maximum flow, 96,500 cusecs in 1943.