WaterFlow

Privacy Policy

Last updated . Effective on the date of WaterFlow’s App Store launch.

This is the privacy policy for WaterFlow, an iPhone and home-screen widget app developed by Thunder Grouse LLC (“we”, “us”). WaterFlow displays real-time water-flow data from U.S. Geological Survey monitoring stations and weather forecasts from the National Weather Service.

The short version

The rest of this page explains exactly how each part of WaterFlow works, so you can verify the short version yourself.

1. What WaterFlow does on your device

WaterFlow runs entirely on your iPhone and the home-screen widget. It performs three categories of work:

  1. Fetches public data from federal agencies. WaterFlow asks the U.S. Geological Survey (waterservices.usgs.gov) for current and historical streamflow readings, and asks the National Weather Service (weather.gov) for forecasts. These are the same public endpoints any web browser can hit. No login or registration is required, and the requests carry no account or device identifier — WaterFlow has none. When you use Nearby, though, the search area in the request is derived from your location (see item 3 below).
  2. Stores your preferences locally. Your favorite stations, alert thresholds, default state, and widget configuration are saved to your iPhone’s secure on-device storage (specifically, to a shared App Group container so the widget can read the same favorites). This storage stays on your device. It is included in your iCloud backup if you have iCloud Backup enabled — that backup is encrypted by Apple, not by us.
  3. Uses your location when you choose to use the Nearby feature. If you tap the Nearby tab, WaterFlow requests “When In Use” location permission from iOS. Your location is used in two ways:
    • It is sent to the USGS API as a bounding box (a rough geographic rectangle, its edges rounded outward to about a kilometer) so the API can return gauges near you.
    • Distances from your phone to each gauge are computed locally to sort and display the list.
    Your location is not stored and not logged by WaterFlow. The rough bounding box goes to USGS, which needs it to return your results — no one else receives your location. Separately, when you use the Map tab, the region of the map you’re viewing reaches Apple to load the imagery (see Section 3).

WaterFlow does not use background location. It does not track your movement when you aren’t actively using the app. It does not use Always Allow location.

2. What we do NOT collect

To be unambiguous, WaterFlow does not collect, transmit, or share any of the following:

3. Network communication, in detail

WaterFlow makes network requests to three services:

U.S. Geological Survey Water Services

National Weather Service

Apple Maps (MapKit)

These three services are the only servers WaterFlow ever contacts. Like any web server, each one can see your device’s IP address when the app talks to it; we never see it, because none of the traffic passes through us. The app has no telemetry endpoint of its own.

4. Permissions WaterFlow requests

WaterFlow asks for these iOS permissions, and only when you trigger the feature that needs them:

WaterFlow does not request access to Photos, Contacts, Calendars, the Microphone, the Camera, HealthKit, Bluetooth, or any other category. You can verify this in iOS Settings › WaterFlow.

5. Push notifications

If you set a flow alert on a station, WaterFlow will check that station’s reading periodically in the background and send you a local push notification when the threshold is crossed. The check is performed on your device by iOS’s BGProcessingTask system. The reading itself is fetched from USGS (see Section 3). Apple’s push notification servers carry the alert from your device to your notification screen — that is Apple’s infrastructure, not ours. We do not see notification delivery records.

6. Children’s privacy

WaterFlow is rated 4+ and does not knowingly collect data from anyone — children included. There is no sign-up, no profile, and no in-app communication. The app complies with the U.S. Children’s Online Privacy Protection Act (COPPA) by virtue of collecting no personal information from anyone.

7. Data retention and deletion

Because WaterFlow stores nothing on a server, there is nothing for us to retain or delete on a server. To delete the data WaterFlow stores on your device, do one of the following:

This removes all of WaterFlow’s locally stored preferences, favorites, and alert configuration. The shared App Group container is also removed.

8. International users

WaterFlow handles data the same way everywhere — United States, European Union, United Kingdom, California, anywhere. Here is the honest accounting: the one piece of personal data that leaves your device is the rough search area sent to USGS when you use Nearby. Privacy laws like the GDPR, UK GDPR, and CCPA/CPRA treat even a coarse location as personal data, so we count it too. It is sent solely to answer your own query, it never passes through our hands, we store none of it, we sell none of it, and none of it is used for tracking or profiling.

Those laws also give you rights over personal data a company holds about you — to see it, correct it, or delete it. We hold none: there is no server-side record of you to produce or erase. If you want to confirm that, or ask anything else about this policy, email us (see Section 10).

9. Changes to this policy

We may update this policy as the app evolves — for example, if we add a new feature that talks to a new public API. When we do, we’ll update the “Last updated” date at the top of this page. Material changes (anything that affects what data is collected, transmitted, or shared) will be noted in the App Store release notes for the version that introduces them.

We will not retroactively change what we do with data already on your device.

10. Contact

Questions or concerns about WaterFlow’s privacy:

Thunder Grouse LLC
Email: steelhead@thundergrouse.com

We read every message.