Terms of Service

Last updated: 19 April 2026

1. Introduction

Welcome to Delta Hydro Studio, a web-based engineering tool suite operated by Delta Hydro Engineers (Pty) Ltd, trading as Delta Hydro – The Flood Specialists ("Delta Hydro," "we," "our," or "us"), a company registered in the Republic of South Africa.

These Terms of Service ("Terms") govern your access to and use of the Delta Hydro Studio web application at studio.deltahydro.tech, including all tools, features, content, and services made available through the platform (collectively, the "Service"). By creating an account, accessing, or using the Service, you acknowledge that you have read, understood, and agree to be bound by these Terms, together with our Privacy Policy and Refund & Cancellation Policy, which are incorporated herein by reference.

If you do not agree with any part of these Terms, you must not access or use the Service. If you are using the Service on behalf of a company, organisation, or other legal entity, you represent and warrant that you have the authority to bind that entity to these Terms.

2. Definitions

In these Terms, the following definitions apply:

• "User" means any individual or entity that registers for an account and uses the Service.
• "Engineer of Record" means the professionally registered engineer who assumes responsibility for the design and implementation of any engineering work based on outputs from the Service.
• "Outputs" means any calculations, results, reports, data, maps, or other information generated by the Service in response to User inputs.
• "Credits" means the digital units used to access calculation services within the platform.
• "Input Data" means any data, parameters, coordinates, catchment boundaries, or other information submitted by the User to the Service.
• "Tools" means the engineering calculation tools available through the Service, including but not limited to the Design Flood Estimation Tool, Culvert Designer, Flood Frequency Analysis, and Design Rainfall tools.

3. Nature of the Service — Engineering Decision-Support Tools

Delta Hydro Studio provides automated hydrological and hydraulic calculation tools designed to assist qualified engineers in their professional work. The Service is a decision-support tool only. It is critical that all Users understand the following:

• Outputs are estimates, not certified designs. All calculations, results, and Outputs generated by the Service are approximate estimates based on the methodologies, datasets, and algorithms implemented within the Tools. They are not substitutes for professional engineering judgement, detailed site investigations, or site-specific design.
• Tools can and do produce errors. Despite our best efforts to implement recognised South African and international hydrological methods (including those from SANRAL Drainage Manual, DWS Technical Notes, WRC reports, and similar sources), the Tools may contain errors, inaccuracies, bugs, or limitations. Underlying datasets (rainfall data, regional parameters, DEM-derived catchment properties) may be incomplete, outdated, or inaccurate for specific locations.
• The User must independently verify all Outputs. Every Output generated by the Service must be critically reviewed, verified, and validated by the User before being used in any engineering design, report, or decision. This includes, but is not limited to, verifying Outputs against:
  • Local site conditions and field observations
  • Applicable South African standards (SANRAL Drainage Manual, SANS, municipal bylaws)
  • Regional and municipal stormwater management policies
  • Professional engineering judgement and experience
  • Alternative calculation methods and independent checks
  • Any other relevant standards, guidelines, or regulations applicable to the project
• Delta Hydro does not provide professional engineering services through this platform. The Service does not constitute the provision of professional engineering advice, consulting, or design services. No engineer-client relationship is created between Delta Hydro and Users of the Service.

4. Professional Responsibility & Engineer of Record

The Engineer of Record assumes full and sole responsibility for all engineering designs, decisions, and implementations that incorporate or rely upon Outputs from the Service.

By using the Service, you acknowledge and agree that:

• You are a qualified professional or are working under the direct supervision of a qualified professional who is registered with the relevant professional body (such as ECSA — the Engineering Council of South Africa — or an equivalent body in your jurisdiction).
• You have the professional competence to evaluate the suitability, accuracy, and applicability of all Outputs for your specific project context.
• You will not use Outputs from the Service as the sole basis for any engineering design without performing independent verification and applying professional engineering judgement.
• You understand that hydrological and hydraulic calculations are inherently uncertain and that the methods implemented in the Tools have known limitations, assumptions, and ranges of applicability.
• You are solely responsible for ensuring that your use of the Outputs complies with all applicable laws, regulations, standards, codes of practice, and professional codes of conduct.
• Delta Hydro bears no professional liability for any engineering design, report, or decision made by the User based on Outputs from the Service, whether in whole or in part.

4A. Third-Party Data Sources

The Service incorporates data from third-party providers, including the United States Geological Survey (USGS), the Australian Bureau of Meteorology (BOM), and the South African Department of Water and Sanitation (DWS), as well as scientific datasets such as the Lynch (2003) Water Research Commission daily rainfall database. Such data is provided under each provider's respective terms and licenses, summarised on our Data Sources & Attributions page.

BOM design rainfall and gauging data is © Commonwealth of Australia, licensed under Creative Commons Attribution 4.0. USGS data is in the United States public domain. DWS hydrological records are published as a public service. By using these features, you acknowledge each upstream provider's terms.

Delta Hydro Studio makes no warranty as to the accuracy, completeness, currency, or fitness for purpose of any third-party data. Inclusion of these datasets does not imply endorsement of Delta Hydro Studio by USGS, BOM, DWS, or any other agency. You are responsible for complying with the terms and attribution requirements of each upstream provider when redistributing outputs that incorporate such data.

5. User Accounts & Registration

To access the Tools, you must register for a user account. When registering, you agree to:

• Provide accurate, current, and complete information during registration.
• Maintain the security and confidentiality of your account credentials.
• Promptly update your account information if it changes.
• Accept responsibility for all activities that occur under your account.
• Notify us immediately at support@deltahydro.tech if you suspect any unauthorised use of your account.

We reserve the right to suspend or terminate accounts that contain false information, are used for fraudulent purposes, or violate these Terms. You may not create multiple accounts for the purpose of circumventing credit limits, usage restrictions, or account suspensions.

6. Subscriptions, Credits & Payment

Access to the Service is provided via a free tier and paid subscription plans, together with an optional credit-pack top-up system. The following terms apply:

• Merchant of record: All payments for subscriptions and credit packs are processed by Paddle.com Market Ltd ("Paddle"), our merchant of record. Paddle handles payment processing, tax calculation and remittance (including VAT/GST where applicable), invoicing, and refunds on our behalf. By making a purchase, you also agree to Paddle's Checkout Buyer Terms.
• Subscriptions: Paid plans are billed on a recurring monthly or annual cycle, in the currency and amount displayed at checkout. Subscriptions renew automatically until cancelled. You may cancel at any time from your account settings; cancellation takes effect at the end of the current billing period.
• Credit packs: One-off credit packs may be purchased at the prices listed at the time of purchase. Each use of a Tool consumes credits at the rate specified for that Tool, and credit costs may vary between Tools and calculation types.
• Taxes: Prices are displayed exclusive of taxes unless otherwise stated. Paddle will determine and add any applicable sales tax, VAT, or GST at checkout based on your billing location.
• Refunds & cancellation: Refunds, cancellations, chargebacks, and related billing matters are governed by our Refund & Cancellation Policy, which forms part of these Terms. Nothing in these Terms limits your non-excludable rights under the Consumer Protection Act 68 of 2008 or other applicable consumer-protection law.
• System-error credit restoration: If a calculation fails due to a confirmed system error (not due to invalid User inputs or upstream data-provider outages), we will restore the consumed credits to your account.
• Non-transferable: Credits and subscription entitlements are tied to the purchasing account and may not be transferred, sold, or traded to other users or accounts.
• Credit expiry: We reserve the right to implement credit expiry policies. If expiry is introduced, we will provide at least 90 days' notice to all users with active credit balances.
• Price changes: We reserve the right to modify pricing for subscriptions and credit packs. Changes to subscription pricing take effect from your next renewal after at least 30 days' notice; changes to credit-pack pricing will not affect packs already purchased.

7. Acceptable Use

You agree not to use the Service to:

• Reverse engineer, decompile, disassemble, or attempt to derive the source code, algorithms, or underlying methodologies of the Tools.
• Systematically scrape, harvest, or extract data from the Service through automated means (bots, crawlers, scripts, or similar).
• Attempt to circumvent, disable, or interfere with security features, usage limits, or credit mechanisms.
• Use the Service for any unlawful purpose or in violation of any applicable law or regulation.
• Resell, redistribute, or commercially exploit the Service or Outputs without our prior written consent.
• Introduce malware, viruses, or other harmful code to the Service.
• Impersonate another person or entity, or misrepresent your affiliation with any person or entity.
• Overload, flood, or otherwise impair the availability or performance of the Service.

Violation of these acceptable use provisions may result in immediate suspension or termination of your account, forfeiture of remaining credits, and potential legal action.

8. Intellectual Property

Our intellectual property: The Service, including all software, algorithms, user interfaces, designs, logos, trademarks, and documentation, is the intellectual property of Delta Hydro or its licensors and is protected by South African and international intellectual property laws. Nothing in these Terms grants you any right, title, or interest in our intellectual property except the limited right to use the Service in accordance with these Terms.

Your data: You retain ownership of all Input Data you submit to the Service. By submitting Input Data, you grant Delta Hydro a limited, non-exclusive licence to process that data solely for the purpose of providing the Service to you. We will not use your Input Data for any other purpose without your express consent.

Outputs: You may use the Outputs generated by the Service for your professional engineering projects, subject to the disclaimers and limitations set out in these Terms. You may not represent Outputs as having been produced or endorsed by Delta Hydro in any professional report or submission without our prior written consent.

9. Disclaimer of Warranties

Please read this section carefully as it limits our liability to you.

The Service is provided on an "as is" and "as available" basis, without warranties of any kind, either express or implied. To the fullest extent permitted by applicable law, Delta Hydro disclaims all warranties, including but not limited to:

• Accuracy and completeness: We do not warrant that the Outputs, calculations, or data produced by the Service will be accurate, complete, reliable, current, or error-free for any particular purpose or location. Hydrological modelling involves inherent uncertainties, and Outputs are approximations based on available data and methods.
• Fitness for purpose: We do not warrant that the Service or Outputs will be fit for any particular engineering purpose, project, or application. The suitability of Outputs for any specific use must be determined by the User.
• Uninterrupted availability: We do not warrant that the Service will be available at all times, without interruption, or free from defects. We may perform maintenance, updates, or modifications that temporarily affect availability.
• Data integrity: We do not warrant that underlying datasets (including but not limited to rainfall data, regional parameters, DEM data, and catchment delineations) are free from errors or are current for all locations.
• Compliance with standards: While the Tools implement recognised South African and international methodologies, we do not warrant that Outputs will comply with all applicable standards, regulations, or bylaws in every jurisdiction.

No information or advice, whether oral or written, obtained from Delta Hydro or through the Service shall create any warranty not expressly stated in these Terms.

10. Limitation of Liability

To the maximum extent permitted by South African law, including the Consumer Protection Act 68 of 2008:

• No consequential damages: Delta Hydro shall not be liable for any indirect, incidental, special, consequential, or punitive damages, including but not limited to loss of profits, loss of revenue, loss of data, loss of business opportunities, cost of replacement services, property damage, personal injury, or death, arising out of or in connection with your use of or inability to use the Service, even if we have been advised of the possibility of such damages.
• No liability for engineering outcomes: Delta Hydro shall not be liable for any damages, losses, costs, claims, or liabilities arising from any engineering design, construction, infrastructure failure, flood damage, or any other outcome that is based in whole or in part on Outputs from the Service. The Engineer of Record and/or the User assumes full liability for all such outcomes.
• Maximum liability cap: In no event shall Delta Hydro's total aggregate liability to you for all claims arising out of or relating to the Service exceed the total amount of fees paid by you to Delta Hydro in the twelve (12) months preceding the event giving rise to the claim.
• Force majeure: Delta Hydro shall not be liable for any failure or delay in performance resulting from causes beyond our reasonable control, including but not limited to natural disasters, power outages, internet service disruptions, acts of government, pandemics, or third-party service failures.

Some jurisdictions do not allow the exclusion of certain warranties or the limitation of liability for certain types of damages. In such cases, our liability shall be limited to the maximum extent permitted by applicable law. Nothing in these Terms shall exclude or limit liability that cannot be excluded or limited under South African law, including liability for fraud or gross negligence.

11. Indemnification

You agree to indemnify, defend, and hold harmless Delta Hydro, its directors, officers, employees, agents, and affiliates from and against any and all claims, demands, damages, losses, costs, liabilities, and expenses (including reasonable legal fees) arising out of or in connection with:

• Your use of the Service or any Outputs generated by the Service.
• Any engineering design, report, or decision made by you or on your behalf that incorporates or relies upon Outputs from the Service.
• Your breach of these Terms.
• Your violation of any applicable law, regulation, standard, or professional code of conduct.
• Any third-party claim arising from your professional activities that utilised the Service.

12. Data Protection & POPIA Compliance

Delta Hydro Engineers (Pty) Ltd is committed to protecting your personal information in accordance with the Protection of Personal Information Act, 2013 (POPIA) and all applicable South African data protection legislation. Our collection, use, and processing of your personal information is governed by our Privacy Policy.

Our designated Information Officer, in accordance with Section 55 of POPIA, is Robert Fortuin, who can be contacted at info@deltahydro.tech.

By using the Service, you consent to the processing of your personal information as described in our Privacy Policy. Key points include:

• We process personal information only for the purposes specified in our Privacy Policy and with a lawful basis under POPIA.
• You have the right to access, correct, and request deletion of your personal information.
• You have the right to object to the processing of your personal information and to lodge a complaint with the Information Regulator of South Africa.
• We implement appropriate technical and organisational measures to protect your personal information.

13. Service Availability & Modifications

We reserve the right to modify, suspend, or discontinue the Service (or any part thereof) at any time, with or without notice. This includes adding, modifying, or removing Tools, features, or calculation methods.

• We will make reasonable efforts to provide advance notice of significant changes that may affect your use of the Service.
• We are not liable to you or any third party for any modification, suspension, or discontinuation of the Service.
• Scheduled maintenance windows will be communicated in advance where practicable.

14. Termination

Termination by you: You may terminate your account at any time by contacting us at support@deltahydro.tech. Upon termination, any unused credits will be forfeited, and your access to the Service will cease.

Termination by us: We may suspend or terminate your account and access to the Service immediately, without prior notice or liability, if:

• You breach any provision of these Terms.
• We are required to do so by law or regulatory order.
• Your account has been inactive for a period exceeding twelve (12) consecutive months.
• We reasonably believe your account has been compromised or is being used fraudulently.

Effect of termination: Upon termination, the following provisions shall survive: Sections 3 (Nature of the Service), 4 (Professional Responsibility), 8 (Intellectual Property), 9 (Disclaimer of Warranties), 10 (Limitation of Liability), 11 (Indemnification), and 16 (Governing Law).

15. Changes to These Terms

We reserve the right to update or modify these Terms at any time. When we make material changes, we will:

• Update the "Last updated" date at the top of this page.
• Notify registered users by email of material changes that affect their rights or obligations.
• Where required by applicable law, obtain your consent to material changes before they take effect.

Your continued use of the Service after changes are posted constitutes your acceptance of the revised Terms. If you do not agree with the revised Terms, you must stop using the Service and may request account termination.

16. Governing Law & Dispute Resolution

These Terms shall be governed by and construed in accordance with the laws of the Republic of South Africa, without regard to its conflict of law provisions.

Any dispute arising out of or in connection with these Terms or the Service shall be subject to the exclusive jurisdiction of the courts of the Republic of South Africa. Before commencing legal proceedings, the parties agree to attempt to resolve any dispute through good-faith negotiation for a period of not less than thirty (30) days.

Nothing in this clause shall prevent either party from seeking urgent interim relief from a court of competent jurisdiction where necessary to protect its rights.

17. Consumer Protection Act Compliance

To the extent that the Consumer Protection Act 68 of 2008 ("CPA") applies to these Terms or the Service:

• Nothing in these Terms is intended to limit or exclude any rights you may have under the CPA that cannot be limited or excluded by agreement.
• Where any provision of these Terms conflicts with a mandatory provision of the CPA, the CPA provision shall prevail.
• You have the right to fair, reasonable, and honest dealing as provided for in the CPA.

18. Electronic Communications & Transactions Act

In accordance with the Electronic Communications and Transactions Act 25 of 2002 ("ECTA"):

• These Terms constitute an electronic transaction and are binding upon acceptance.
• By accepting these Terms, you consent to receiving communications from us electronically, including service notifications, account updates, and legal notices, via the email address associated with your account.
• Data messages (including emails and notifications) sent by Delta Hydro shall be deemed received by you when they enter your designated information system (i.e., your email inbox).

19. General Provisions

• Entire agreement: These Terms, together with the Privacy Policy and the Refund & Cancellation Policy, constitute the entire agreement between you and Delta Hydro regarding the Service and supersede all prior agreements, understandings, and communications.
• Severability: If any provision of these Terms is found to be invalid, illegal, or unenforceable by a court of competent jurisdiction, the remaining provisions shall continue in full force and effect.
• Waiver: No failure or delay by Delta Hydro in exercising any right under these Terms shall constitute a waiver of that right. A waiver of any right on one occasion shall not be deemed a waiver of that right on any subsequent occasion.
• Assignment: You may not assign or transfer your rights or obligations under these Terms without our prior written consent. Delta Hydro may assign its rights and obligations under these Terms without restriction.
• No third-party rights: These Terms do not confer any rights on any person or entity other than the parties to these Terms and their respective successors and permitted assigns.

20. Contact Us

For any questions, concerns, or legal enquiries regarding these Terms, please contact us:

• General enquiries: info@deltahydro.tech
• Technical support: support@deltahydro.tech
• Legal enquiries: legal@deltahydro.tech
• Phone: 083 302 6095