Terms of Use

1. Ownership and Copyright

This website, including all content, calculations, council data, tank databases, source code, design, and documentation, is the intellectual property of Subdivision and Engineering Ltd (SAE Ltd), trading as NZ Detention Tank Calculator.

© 2026 Subdivision and Engineering Ltd. All rights reserved.

No part of this website, its source code, data, or reports may be reproduced, copied, distributed, modified, reverse-engineered, or used to create derivative works without the prior written consent of SAE Ltd.

2. Permitted Use

You may use this calculator to:

• Size stormwater detention and retention tanks for specific projects in New Zealand.
• Generate PDF reports for submission to councils.
• Share the website URL with colleagues, clients, and council staff.

3. Prohibited Use

You may not:

• Copy, reproduce, or redistribute the source code, council data, tank database, or calculation methodology.
• Scrape, extract, or programmatically access the data on this website.
• Create a competing product or service using data or methods derived from this website.
• Remove or alter any copyright notices, branding, or attribution.
• Use this website for any unlawful purpose.

4. Disclaimer

This calculator provides sizing estimates based on published council standards and engineering codes of practice. Results are intended as a guide and must be verified by a suitably qualified person (CPEng or equivalent) before submission to any council.

SAE Ltd accepts no liability for:

• Errors or omissions in calculations, council data, or tank specifications.
• Changes to council standards, bylaws, or engineering codes of practice that have not yet been reflected in this calculator.
• Decisions made based on the output of this calculator.
• Any loss, damage, or costs arising from the use of this website.

Council requirements change regularly. Always confirm current requirements with the relevant territorial authority before relying on these calculations.

5. Council Data

The council-specific data in this calculator has been compiled from publicly available council standards, engineering codes of practice, and design guidance documents. While every effort is made to keep this data accurate and current, SAE Ltd does not guarantee that all council information is up to date.

Source documents for each council are referenced within the calculator. If you identify an error or outdated information, please contact us.

6. Tank Data

Tank specifications and pricing are sourced from manufacturer websites and published brochures. Prices are estimates only and may vary. Always confirm specifications and pricing directly with the tank supplier before purchasing.

7. Privacy

When you use this calculator, we may collect:

• Your email address (if provided for PDF download or feedback).
• Anonymous usage data via Google Analytics (pages visited, council selected, calculator usage).

We do not sell or share your personal information with third parties. Email addresses are used only to send product updates and will not be shared.

8. Third-Party Links

This website contains links to council websites and tank supplier websites. SAE Ltd is not responsible for the content, accuracy, or availability of these external sites.

9. Changes to Terms

SAE Ltd reserves the right to update these terms at any time. Continued use of the website constitutes acceptance of the current terms.

10. Contact

For questions about these terms, to report errors, or to request permission to use content from this website:

Subdivision and Engineering Ltd
Email: andre@subeng.nz
Website: subeng.nz