Last updated: April 2026
1. What Are Cookies
Cookies are small text files that are placed on your computer or mobile device when you visit a website. They are widely used to make websites work more efficiently, to provide a better user experience, and to supply information to the owners of the site. Cookies allow a website to recognise your device, remember your preferences, and understand how you interact with the site over time.
When we refer to "cookies" in this policy, we include cookies and similar tracking technologies such as local storage and session storage used by our website (deltahydro.tech) and our web application (studio.deltahydro.tech).
2. Types of Cookies We Use
We use the following categories of cookies across our website and application:
2.1 Essential Cookies
These cookies are strictly necessary for the operation of our website and application. They enable core functionality such as security, session management, and user authentication. Without these cookies, the services you have requested cannot be provided. Essential cookies do not require your consent as they are necessary for the site to function.
- Session management and maintaining your login state
- User authentication and secure access to your account
- Security features such as CSRF protection
- Load balancing and server routing
2.2 Functional Cookies
Functional cookies allow our website and application to remember choices you make and provide enhanced, more personalised features. These cookies may be set by us or by third-party providers whose services we have added to our pages.
- Remembering your display preferences and UI settings
- Storing your selected calculation methods and tool configurations
- Remembering your preferred map view and project settings
- Language and regional preferences
2.3 Analytics Cookies
Analytics cookies help us understand how visitors interact with our website and application by collecting aggregated, anonymised data. We classify product analytics as essential because we rely on this data to diagnose bugs, measure performance, and prioritise improvements to Delta Hydro Studio. All analytics data is aggregated and does not identify you personally.
When you first visit deltahydro.tech or docs.deltahydro.tech, a banner invites you to accept optional cookies (personalization and future marketing uses) or to decline them. Declining optional cookies does not disable analytics. To revoke analytics consent entirely, clear the dh-consent cookie in your browser — note that by continuing to use Delta Hydro Studio you accept the terms that classify analytics as essential.
- Tracking page views, session duration, and navigation patterns
- Understanding which tools and features are most used
- Identifying areas for performance improvement
- Monitoring site health and error rates
3. Cookie Details
The following table provides details about the specific cookies used on our website and application:
| Cookie Name | Purpose | Type | Duration |
|---|---|---|---|
| session_id | Maintains your session state while you are logged into the application | Essential | Session |
| auth_token | Authenticates your identity and keeps you securely logged in | Essential | 7 days |
| csrf_token | Protects against cross-site request forgery attacks | Essential | Session |
| dh-consent | Remembers your cookie consent choice across Delta Hydro sites (deltahydro.tech, studio.deltahydro.tech, docs.deltahydro.tech) | Essential | 180 days |
| user_preferences | Remembers your display settings, preferred units, and UI configuration | Functional | 12 months |
| tool_config | Stores your last-used tool settings and calculation method selections | Functional | 6 months |
| map_view | Remembers your preferred map zoom level and view position | Functional | 6 months |
| _ga | Google Analytics — distinguishes anonymous users across sessions | Essential (analytics) | 2 years |
| _ga_JQ0RWRXXQ6 | Google Analytics — preserves session state for the Delta Hydro property | Essential (analytics) | 2 years |
4. Third-Party Cookies
In some cases, we use trusted third-party services that may also set cookies on your device. These third parties include:
- Google Analytics (GA4, property
G-JQ0RWRXXQ6) – we use GA4 to understand how visitors use our website and application. GA4 is configured with Consent Mode v2; advertising and personalization signals are denied by default and only sent to Google if you click "Accept all" on the consent banner. For more information, see Google's Privacy Policy. - Map tile providers – our application uses mapping services to display geographic data. These providers may set cookies to deliver map tiles and optimise performance.
- Paddle – our payment-processing partner may use cookies to facilitate secure transactions when you purchase a subscription or credit pack.
We do not control the cookies set by third parties. We recommend reviewing the respective privacy policies of these third-party services for more information about their use of cookies.
5. How to Manage Cookies
You have the right to decide whether to accept or reject cookies. Most web browsers allow you to control cookies through their settings. Below are instructions for managing cookies in the most common browsers:
- Google Chrome: Settings → Privacy and Security → Cookies and other site data
- Mozilla Firefox: Settings → Privacy & Security → Cookies and Site Data
- Microsoft Edge: Settings → Cookies and site permissions → Manage and delete cookies and site data
- Safari: Preferences → Privacy → Manage Website Data
Please note that if you choose to block or delete cookies, some features of our website and application may not function correctly. Essential cookies cannot be disabled as they are required for the site to operate. Blocking these cookies may prevent you from logging in or using core functionality of the Delta Hydro application.
You can also opt out of Google Analytics tracking by installing the Google Analytics Opt-out Browser Add-on.
6. Cookie Duration and Retention
Cookies can be either "session" cookies or "persistent" cookies:
- Session cookies are temporary and are deleted from your device when you close your browser. We use session cookies to maintain your login state and protect your security during a browsing session.
- Persistent cookies remain on your device for a set period or until you manually delete them. We use persistent cookies to remember your preferences and settings so that you do not have to re-enter them each time you visit. The duration of each persistent cookie is detailed in the cookie table above.
We regularly review the cookies we use and their retention periods to ensure we only store data for as long as necessary to fulfil the purposes described in this policy.
7. Updates to This Policy
We may update this Cookie Policy from time to time to reflect changes in technology, legislation, our business operations, or our use of cookies. When we make material changes, we will update the "Last updated" date at the top of this page. We encourage you to review this policy periodically to stay informed about how we use cookies.
Your continued use of our website and application after any changes to this policy constitutes your acceptance of the updated policy.
8. Contact Us
If you have any questions about this Cookie Policy, our use of cookies, or your privacy, please do not hesitate to contact us:
- General enquiries: info@deltahydro.tech
- Technical support: support@deltahydro.tech
- Legal / privacy requests: legal@deltahydro.tech