The annual volume calculator is an Excel spreadsheet which is intended to enable you to calculate an annual volume for a specific area of irrigated land.
What is the annual volume calculator?
The Annual Volume calculator is an Excel spreadsheet which is intended to enable you to calculate an annual volume for a specific area of irrigated land. The calculator is based on a revised version of the 
WQN9 Schedule (pdf 3.58 MB).
To use the calculator you will need some specific technical information about your actual or intended irrigated area.
A definition of technical terms used can be seen by visiting the glossary page.
Further information about WQN9
To find out more information abouy WQN9 and annual volume, we have prepared the document below. It provides
- A general introduction to Schedule WQN9v3 and annual volumes on resource consents
- Information regarding policies and rules relevant to annual volume requirements
- Guidance notes on how to calculate annual volumes under Schedule WQN9v3
- Frequently asked questions (and answers) about annual volumes and Schedule WQN9v3
- Examples of the application of relevant policies
- Consent reviews
- Glossary of relevant terms
Read Annual volumes and Schedule WQN 9 (pdf 56 kB)
How do I use the calculator?
Whether you already have an existing consent for the area or your interest is in applying for a new consent, the valuation or legal description for all relevant land parcels will be helpful. Alternatively, you can search by entering the name of an adjacent road.
If you want to calculate the annual volume for more than one consent or if land parcels are geographically separate, you will have to run a separate calculation for each consent/land parcel.
You will need the following information from your pumping schedule:
- The maximum volume (actual or intended) per Return Period Return Period is the time (in days) between successive irrigations.
- Length of return period (actual or intended).
To find this information:
The instructions on the use of the spreadsheet show how to determine the maximum volume if it is not explicitly stated in an existing consent.
You will also need to know:
- The area to be irrigated in hectares
- Land-use type (actual or intended) e.g. arable, Intensive Pasture
- Profile Available Water (PAW)
- Effective irrigation season rainfall.
To find this information:
Information on Profile Available Water (PAW) and Effective irrigation can be obtained using our Online GIS mapping tool.
To make this calculator work:
Your computer will need to have a version of MS Excel 97 or later for the calculator to function. If you do not have this, you may still be able to use the online GIS mapping tool to get some useful information, but not an annual volume. You will need to contact Environment Canterbury customer services for help.
Getting started:
Open the Calculator (xls 48 kB) (opens in a new window). From here you can download the Calculator to your computer and save it if you wish.
You can also print out the Calculator spreadsheet at any time by clicking on the File menu from the top left of your browser window and selecting Print. This will prompt you to print the spreadsheet (including the data you have entered) to your computer printer. - Open the Calculator instructions (opens in a new window). These will advise you how to use the calculator and GIS to extract your annual volume.
- Check the consent details sent to you from Environment Canterbury, or Find consent information online (opens in a new window)
- Open our online GIS mapping tool (opens in a new window)
Please note, you will need to keep the consent details near and also have the GIS mapping tool and instructions open while you use the calculator.