Wainui River (Bay of Plenty) river. Wainui River (Bay of Plenty) The Wainui River is a river of the Bay of Plenty Region of New Zealand's North Island. It flows north from the Kaimai Range to reach Tauranga Harbour south of Katikati. The catchment has of stream margins. 41% of the catchment remains covered in native bush, but 48% is under pasture and suffers soil erosion. The river includes 3 waterfalls of up to , which have been kayaked. The long former East Coast Main Trunk railway bridge is designated as the limit of the Coastal Marine Area. Downstream, a 3-span bridge takes SH2 over
Bay of Plenty is emerging as a major regional source of electricity. Tourism is the other notable industry, accounting for 15% of the region's GDP from March 2000 to 2004. Overall economic growth in the Bay of Plenty averaged 2.1% between March 2000 and 2004, compared with the national rate of 3.5%, although per capita real GDP growth in the five years to March 2003 matched the national growth rate at an averaged 2.3%. In the 2006 Census, the median annual income was $22,600, below the national median of $24,400. Further, 45.4% of people aged 15 years or older earned an annual income