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Tapu flood protection scheme design report

TR 2013/44
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Report: TR 2013/44

Author: Megan Wood (Wainui Consulting Limited)

About this report

The purpose of this Design Report is to provide a summary of the works that have been undertaken at Tapu to reduce the flood hazard from Tapu River, including the rationale behind the scheme development, the agreed levels of service, the design details, as built information, the operation and maintenance requirements of the scheme, the residual flood risk and the scheme review requirements.

The Design Report includes the following sections:

  • Catchment overview
  • Hydrological assessment
  • Hydraulic model development
  • Scheme design
  • Agreed levels of service
  • Operation and maintenance
  • Flood hazard assessment
  • Residual flood risk
  • Planning controls, and
  • Scheme review.

Read or download the report

Tapu flood protection scheme design report [PDF, 2.6 MB]

Contents
  Executive summary iv
1 Introduction 1
1.1 Background 1
1.2 Scope of report 1
2 Catchment overview 2
2.1 Catchment description 2
2.2 Tapu River 3
2.3 Flooding issues 4
3 Hydrological assessment 6
3.1 Technical information 6
3.2 Catchment characteristics 7
3.3 Rainfall 7
3.4 Flow estimates 8
3.5 Hydrograph 8
4 Hydraulic model development 10
4.1 Introduction 10
4.2 MIKE-21 model 10
4.3 MIKE-11 model 12
4.4 Peer review 12
5 Flood protection scheme 13
5.1 Community input 13
5.2 Channel improvements 13
5.3 Scheme development 13
5.4 Scheme design 14
5.5 Future works 20
6 Agreed levels of service 21
7 Operation and maintenance 23
8 Flood hazard assessment 24
8.1 River flood hazard classification 24
8.2 River flood hazard map 25
9 Residual flood risk 26
10 Planning controls 27
11 Scheme review 28
  References 29
  Appendix 1: Peer review of hydraulic models 30
  Appendix 2: Design details 31
  Appendix 3: As-built survey 39