Kaituna Asset Management Plan
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Kaituna Asset Management Plan Prepared by Philip Wallace, Technical Services Department Environment Bay of Plenty Operations Report 2003/09 October 2003 5 Quay Street P O Box 364 Whakatane NEW ZEALAND ISSN 1173 - 6232 Working with our communities for a better environment Environment Bay of Plenty i Foreword This plan is a statement by Environment Bay of Plenty, the Manager of the Kaituna Catchment Control Scheme, as to how it will manage the river and lake control assets of the scheme. The plan represents prudent management as required by the Local Government Act 2002 including Section 90 of the Act, namely the Policy on Significance. This updated edition meets the requirements of the asset management improvement plan. Operations Report 2003/09 Kaituna Asset Management Plan Environment Bay of Plenty iii Executive Summary The purpose of this plan is to provide a document for the management of the flood control and lake level control elements of the Kaituna Catchment Control Scheme and in particular its infrastructural assets. The Scheme has been split at Okere into two areas: the “Upper Kaituna” i.e. Lakes Rotorua and Rotoiti and their tributaries, and the “Lower Kaituna” i.e. the lower Kaituna River and tributary streams, canals and drainage network This plan supersedes the 1998 Lower Kaituna River Scheme Asset Management Plan. It establishes and communicates the level of funding required to maintain and meet the scheme objectives and levels of service. The plan covers the assets of the scheme including stopbanks, rockwork and other erosion protection measures, channels, lake level control structures pumps and various other major structures. The current valuation at June 2003 (in terms of Local Government Act requirements) of the Upper Kaituna assets is $3.3 million, while for the Lower Kaituna it is $28.5m. Maintenance programmes are already in place and these have ensured that the assets are in good condition and are providing the desired levels of service. Environment Bay of Plenty through its day-to-day management of the scheme receives continuous feedback about the scheme. Informal feedback to date indicates strongly that the ratepayers support the scheme objectives as espoused at the time of construction. Service levels have therefore been defined to ensure the original scheme objectives are met and maintained. The stopbanks will be maintained to a level to ensure the design flood can be conveyed. Settlement of up to 50% of the freeboard will be allowed before stopbank reconstruction will be undertaken. All structures will be maintained in a workable condition at all times to function to their design standards. Rockwork will be maintained at all times to a minimum of 75% of the original design placement rate. Environment Bay of Plenty has a number of tools, which are utilised for the management of its assets. Information systems have been purchased and developed to assist the asset managers with general management, maintenance, operations and long term planning. The principal components are the asset management plans, asset register, Decfin Asset Management Module and the Decfin Financial Management System. Environment Bay of Plenty has developed a maintenance programme strategy, which will provide for the most efficient and economic operation, to the desired service levels. A detailed assessment has been undertaken of the work requirement, to provide for the long term, sustainable management of the scheme assets. The scheme has been separated into a number of locations and the key maintenance issues have been identified for each of these. Operations Report 2003/09 Kaituna Asset Management Plan iv Environment Bay of Plenty The average annual level of expenditure required to meet the scheme objectives and the desired levels of service, over the 50 year time horizon of the plan, is comparable to existing expenditure. However, some increase is brought about by the requirements of asset management and monitoring, establishment of a flood damage reserve and by the requirement to fund decline in service potential (depreciation). It is estimated that an average of $210,000 and $722,000 per year will generally be required for the Upper and Lower Kaituna areas respectively. These sums will allow the regular and ongoing maintenance or renewal expenditure necessary to keep the assets operating at the required level of service and provide an allowance for occasional significant flood damage repairs. They also include contributions to flood damage and disaster reserves, investigation projects and loan servicing. However they do not include the costs that may be required to fund more extreme flood or disaster damage repairs beyond the levels predicted in the plan. The scheme is funded largely by scheme rates, with a regional ratepayer contribution and minor miscellaneous other revenue making up the balance. Regular internal and external independent audits will be carried out to establish a continuous improvement cycle, maintain best practices and to assess the quality of asset management. NB: Dollars are expressed in June 2003 values other than where original scheme contract costs are given or as unless otherwise noted. Kaituna Asset Management Plan Operations Report 2003/09 Environment Bay of Plenty Contents Foreword .................................................................................................i Executive Summary...............................................................................iii Chapter 1: Introduction ..........................................................................1 1.1 Asset to be Managed .....................................................................................1 1.2 Scheme History ..............................................................................................6 1.2.1 Lower Kaituna...................................................................................................6 1.2.2 Upper Kaituna...................................................................................................6 1.2.3 Combined Scheme...........................................................................................7 1.3 Rationale for Ownership................................................................................7 Chapter 2: General Information.............................................................9 2.1 Purpose and Ownership of the Plan ............................................................9 2.2 Legislative Requirements..............................................................................9 2.3 Duration of the Plan .....................................................................................10 2.4 Principal Scheme Features – Upper Kaituna ............................................10 2.4.1 Catchment Description ...................................................................................10 2.4.2 Overview.........................................................................................................11 2.4.3 Ohau Channel ................................................................................................12 2.4.4 Okere Gates ...................................................................................................13 2.4.5 Waingaehe Stream.........................................................................................14 2.4.6 Puarenga Stream ...........................................................................................17 2.4.7 Utuhina, Mangakakahi, Otamatea..................................................................19 2.4.8 Waiowhiro Stream ..........................................................................................22 2.4.9 Ngongotaha Stream .......................................................................................23 Operations Report 2003/09 Kaituna Asset Management Plan Environment Bay of Plenty 2.4.10 Waiteti Stream................................................................................................ 25 2.4.11 Other Streams................................................................................................ 26 2.5 Principal Scheme Features: Lower Scheme ............................................. 27 2.5.1 Catchment Description................................................................................... 27 2.5.2 Overview ........................................................................................................ 28 Chapter 3: Assets ................................................................................ 29 3.1 Objectives of the Scheme ........................................................................... 29 3.1.1 Upper Kaituna ................................................................................................ 29 3.1.2 Lower Scheme ............................................................................................... 30 3.2 Description of the Assets............................................................................ 30 3.2.1 Stopbanks ...................................................................................................... 30 3.2.2 Concrete Walls............................................................................................... 30 3.2.3 Channels ........................................................................................................ 30 3.2.4 Structures....................................................................................................... 30 3.2.5 Erosion Protection.........................................................................................