Water Colour  Privacy Policy

Last updated: 14 September 2026

Water Colour is a citizen-science app for recording the colour of rivers. This policy explains what information the app collects, why, who it's shared with, and the choices and rights you have. We've tried to write it in plain English.

Who we are. Water Colour is operated by Ben Strak / Studio Strak ("we", "us"). If you have any questions about this policy or your data, contact us at benjaminstrak@gmail.com.

The short version

• You can use Water Colour anonymously — no account is needed to start.
• Each capture records a photo of the water and where it was taken.
• Photos and approximate locations are shared with the community (that's the point of the app — a shared picture of our rivers). Your exact location is never shared — locations shown to others are deliberately blurred to about a kilometre.
• You can delete any of your captures at any time, which removes them from the shared map too.
• We never sell your personal data or use it for advertising. Anonymised river data (never your identity or exact locations) may be shared with or licensed to researchers, charities, and environmental organisations.

What we collect and why

1. Captures (photos + colour + location)

When you take a capture, the app stores:

• the photo of the water,
• the colour it derives from that photo and the name it assigns,
• the GPS location where the photo was taken, and the nearest matched river,
• the date and time.

Why: this is the core purpose of the app — to build a shared, living record of the colour of rivers.

Anyone can report a capture from its page; we review reports within 24 hours and remove content that breaks our Terms of Use.

2. Camera access

Used only to take capture photos, when you choose to. The app doesn't access your photo library or record without your action.

3. Location access

Used to identify the river you're near and to place your capture on the map. We request location "while using the app" only.

4. Anonymous identifiers

Every install is given an anonymous ID so your captures belong to you and can be restored. This isn't tied to your real identity unless you choose to sign in.

5. Sign in with Apple (optional)

If you sign in, we receive the identifier Apple provides and, if you allow it, your email (which may be Apple's private relay address). Why: so your captures sync across your own devices. You can use the whole app without ever signing in.

6. Feedback (optional)

If you use the in-app "Share feedback" feature, the message you write — along with your email (if signed in) and the app version — is sent to our team's messaging channel so we can read and act on it.

7. Weather context

To describe conditions around a capture, the app asks Apple's WeatherKit service about the weather at the capture's location and date. This is handled under Apple's own privacy terms.

8. Usage analytics

We use PostHog, hosted in the EU, to understand how the app is used: for example how many people complete onboarding, make a capture, and come back. Events are tied to the same anonymous account identifier used for your captures, so we can see patterns across visits, but they never include your location, photos, notes, or river names. We do not use analytics to track you across other apps or websites.

We don't collect advertising identifiers, contacts, or browsing history.

What is public, and what is private

Water Colour is a shared project, so some data is visible to other users. We've drawn the line deliberately:

Shared with the community:

• your capture photos,
• the colour, river name, and date of each capture,
• an approximate location, rounded to about one kilometre, so captures can tint the right stretch of river on the map.

Kept private to you:

• your exact GPS coordinates (only you can see the precise location of your own captures),
• your email and account identity.

Because photos are shared, please only photograph the water — not people, faces, vehicle number plates, or anything you wouldn't want to be public — and avoid capturing right outside your home if you'd rather not reveal roughly where that is.

Who else handles your data (processors)

We use trusted third parties to run the app:

• Supabase — stores captures, photos, and account information on our behalf. Data is stored on servers located in the European Union; appropriate safeguards apply to any transfers outside the UK/EEA.
• PostHog — receives anonymous usage events (which screens are opened, when a capture is made) tied to the same anonymous account identifier as your captures, never your location, photos or notes. Hosted in the European Union.
• Apple — provides Sign in with Apple, WeatherKit, MapKit, and TestFlight (during the beta). Governed by Apple's privacy policy.
• Slack — receives in-app feedback messages you choose to send.

We do not sell your personal data to anyone.

Research and partnerships

Part of Water Colour's purpose is to build a public picture of river health. We may share or license capture data — colours, river names, dates, approximate locations, and capture photos — with research institutions, universities, charities, and environmental agencies, including on commercial terms. When we do, the data is aggregated or anonymised: it never includes your name, email, account identity, or exact GPS coordinates.

Legal basis (UK/EU GDPR)

Where UK/EU data protection law applies, we rely on:

• Consent — for camera and location access (you grant these through iOS, and can withdraw them anytime in Settings), and for sharing your captures publicly by choosing to capture.
• Legitimate interests — to operate the app, keep it secure, and respond to feedback.

Keeping your data / your rights

• Deletion: you can delete any capture in the app (the trash icon on your own captures), delete all your captures, or delete your whole account, from Account → your data. Deleting your account removes every capture, photo and your sign-in.
• Retention: captures are kept until you delete them or ask us to remove your data.
• Backups: your journal (including exact locations) and photos are stored on your device and are included in your device backup (iCloud or computer), which Apple encrypts.
• Your rights: under UK/EU law you can request access to, correction of, or erasure of your personal data, and object to or restrict certain processing. Contact us to exercise these.
• Complaints: if you're in the UK, you can complain to the Information Commissioner's Office (ICO) at ico.org.uk.

Security

Data is transmitted over encrypted HTTPS connections. Access to stored data is protected by row-level security so that only you can read your own private information (such as your exact locations), and only you can modify or delete your own captures.

Children

Water Colour is not directed at children under 13. We don't knowingly collect data from children. If you believe a child has provided us data, contact us and we'll remove it.

Changes to this policy

We may update this policy as the app evolves. We'll change the "Last updated" date above, and for significant changes we'll make a reasonable effort to notify users.

Contact

Ben Strak / Studio Strak
benjaminstrak@gmail.com