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
Lake Rotoiti (Bay of Plenty) divert the nutrient rich waters of Lake Rotorua into the Kaituna River was completed in late 2008. The Bay of Plenty Regional Council expected to see improvement in lake water quality within five years and the Rotorua Te Arawa Lakes Program reported in 2013 that the intervention has significantly improved water quality. Water quality is the highest it has been in decades, on track to meet targets set by the Program to meet community expectations. Lake Rotoiti has thermal hot-spring baths on the southern shore which are accessible by boat. Lake Rotoiti (Bay of Plenty) Lake Rotoiti is a lake