Environment Bay of Plenty i Date of last update: 24 June 2010 Cover Photo: Text to follow. Flood Warning Manual July 2008 Environment Bay of Plenty iii Contents Chapter 1: Introduction ..........................................................................1 1.1 Flood manual purpose......................................................................................3 1.2 How to use this manual ....................................................................................3 1.3 The climate and weather of the Bay of Plenty Region ......................................3 1.4 Setting up the flood room..................................................................................4 1.5 IT Equipment During Power Cuts .....................................................................6 1.6 Communication.................................................................................................6 1.7 Security.............................................................................................................7 Chapter 2: Flood Warnings and Flood Warning Procedures..............9 2.1 Flood warning procedure................................................................................11 2.2 Emergency response work assistance ...........................................................11 2.3 Meteorological office warnings .......................................................................11 2.4 Issuing warnings to the media ........................................................................12 2.5 Telemetered sites ...........................................................................................13 2.6 Civil defence ...................................................................................................16 2.7 Police..............................................................................................................17 Chapter 3: Otara River..........................................................................19 3.1 Warnings and warnings lists ...........................................................................21 3.2 Otara River telemetry sites .............................................................................22 3.3 Otara Catchment hydrological characteristics ................................................22 3.4 Current stopbank design standards (includes Waioeka).................................23 3.5 Predicted warning stages and travel times .....................................................23 3.6 Previous floods ...............................................................................................25 3.7 Flood warning phone lists...............................................................................27 Flood Warning Manual July 2008 iv Environment Bay of Plenty Chapter 4: Waioeka River.................................................................... 29 4.1 Warnings........................................................................................................ 31 4.2 Waioeka telemetry sites ................................................................................. 31 4.3 Waioeka Catchment hydrological characteristics........................................... 32 4.4 Current stopbank design standards (includes Otara)..................................... 33 4.5 Predictable warning stages and travel times.................................................. 33 4.6 Previous floods .............................................................................................. 35 4.7 Flood warning phone lists .............................................................................. 37 Chapter 5: Waimana River .................................................................. 39 5.1 Warnings and warnings lists .......................................................................... 41 5.2 Flood warning phone list ................................................................................ 43 Chapter 6: Whakatane River ............................................................... 45 6.1 Warnings and warning list .............................................................................. 47 6.2 Whakatane and Waimana telemetry sites...................................................... 47 6.3 River floods .................................................................................................... 48 6.4 Previous floods .............................................................................................. 49 6.5 Culverts, floodgates and pump stations ......................................................... 50 6.6 The Whakatane River spit.............................................................................. 50 6.7 Flood protection stoplog structures ................................................................ 53 6.8 Te Rahu basin and spillway ........................................................................... 55 6.9 Rangitaiki Plains............................................................................................. 56 6.10 Flood warning phone list ................................................................................ 57 Chapter 7: Rangitaiki River ................................................................. 59 7.1 Rangitaiki Catchment hydrological characteristics ......................................... 60 7.2 Historical flood protection............................................................................... 60 7.3 Warnings and warning list .............................................................................. 60 July 2008 Flood Warning Manual Environment Bay of Plenty v 7.4 Telemetry sites ...............................................................................................61 7.5 Rangitaiki rainfall ............................................................................................61 7.6 Culverts, floodgates, and pump stations.........................................................62 7.7 Flood control system and spillway ..................................................................62 7.8 Minor floods ....................................................................................................63 7.9 Major floods ....................................................................................................63 7.10 Landowners in Rangitaiki floodway ................................................................64 7.11 Flood estimation .............................................................................................64 7.12 Fonterra Limited Edgecumbe .........................................................................67 7.13 Pressure Relief Trench Monitoring Procedure................................................67 7.14 Matahina Dam ................................................................................................67 7.15 Aniwhenua Dam .............................................................................................71 7.16 Wheao Dam....................................................................................................72 7.17 Landowners in the Rangitaiki Floodway .........................................................74 Chapter 8: Tarawera River ...................................................................75 8.1 Introduction and history ..................................................................................77 8.2 Hydrology .......................................................................................................77 8.3 Telemetry sites ...............................................................................................78 8.4 Rain gauge sites.............................................................................................78 8.5 On track..........................................................................................................78 Chapter 9: Kaituna River......................................................................81 9.1 Introduction and history ..................................................................................83 9.2 Warnings and warning list...............................................................................83 9.3 Telemetry sites ...............................................................................................84 9.4 On Track.........................................................................................................84 9.5 Rain gauge readers ........................................................................................85 9.6 Lower Kaituna River: sensitive areas..............................................................85 Flood Warning Manual July 2008 vi Environment Bay of Plenty 9.7 Flood warning phone list ................................................................................ 89 Chapter 10: Lakes ................................................................................ 91 10.1 Lakes Rainfall ................................................................................................ 93 10.2 Lake Rotoiti .................................................................................................... 93 10.3 Lake Rotorua ................................................................................................. 96 10.4 Lake Okareka................................................................................................. 97 10.5 Okere Gates................................................................................................... 99 Chapter 11: Coastal ..........................................................................