Bay of Plenty region was formed in 1989 after a nationwide review and shakeup of top-level local government in New Zealand. The new region incorporated the former counties of Tauranga, Rotorua, Whakatane and Opotiki. On 5 October 2011, the MV Rena ran aground on the Astrolabe Reef in the bay causing a large oil spill, described as New Zealand's worst ever environmental disaster. The region is subdivided into territorial authorities, which include the Western Bay of Plenty District, Tauranga City, Whakatane District, Kawerau District and Opotiki District, as well as parts of Rotorua District and the town of Rangitaiki in Taupo District. The
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