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Waikato stormwater runoff modelling guideline

TR 2018/02

Report: TR 2018/02

Author: Earl Shaver (Aqua Terra International Limited)

About this report

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This is one of two guidelines that address stormwater management:

The Waikato Stormwater Runoff Modelling Guideline is based on Auckland Council’s Technical Publication 108 (TP108) Guidelines for stormwater runoff modelling in the Auckland region (Auckland Regional Council, 1999) and replaces use of this guideline in the Waikato region.

Read or download the report

Waikato stormwater runoff modelling guideline [PDF, 2.8 MB]

Contents

1 Background
1.1 Basis for the design approach
1.2 Hydrological modelling software
2 Analytical overview
3 Limitations of the model
4 Rainfall data
4.1 Temporal pattern
4.2 Design rainfall depth
4.3  Climate change
4.4 Areal reduction factors
5 Estimating runoff
5.1 Retention parameters
5.2 Curve numbers 
5.3 Hydrological soil groups
5.3.1 Dual classification 
5.3.2 Hydrologic soil group assignment
5.3.3 Site soil testing to determining hydrologic soil group
5.4 Land use cover parameters
6 Runoff calculations 
6.1 Unit hydrograph
7 Time of concentration 
7.1 Sheet and shallow concentrated flow 
7.2 Concentrated network flow
7.2.1 Time of road channel flow 
7.2.2 Time of pipe network flow
7.2.3 Open channel flow
7.3 Catchment flow
7.4 Alternative equations
8 Analysis
8.1 Incorporation of Ia retention in runoff peak and volume calculations
9 Examples
9.1 Case study 1
9.2 Case study 2
References
Appendix A: Runoff curve numbers
Appendix B: Worksheets