# Privacy Policy for Core Hydrology & Hydraulics

Last updated: 2026-03-30

## Overview

Core Hydrology & Hydraulics (the “App”) performs engineering calculations locally on your device. It is designed to work fully offline. No personal information such as name, email, precise location, contacts, or unique identifiers is collected, sold, or shared.

## Data Collected

By default, the App does **not** collect analytics data. You may optionally enable **anonymous usage analytics** via the in-app toggle.

### If analytics is enabled

The following event data may be sent to Firebase Analytics:

- `formula_used`: formula name such as Manning, Rational, or Hazen-Williams

- Unit system used (SI / US)

- Calculation mode (depth to flow or flow to depth, where applicable)

- Warning count generated during the calculation

These events are aggregated and are **not** linked to your identity. They do not include user-entered numeric values such as flow rates, depths, channel dimensions, or rainfall values. No personally identifiable information (PII) is transmitted.

### If analytics is disabled

No events are logged. You can disable analytics at any time and future events stop immediately.

## Data Not Collected

The App does **not** collect:

- Names, email addresses, or phone numbers

- Precise GPS location

- Files, photos, or contacts

- Individual numeric input values

- Advertising identifiers (no ads are currently integrated)

## Storage

Calculation inputs and outputs reside only in volatile memory while the App runs. Exported PDFs you create are saved locally using standard device storage APIs. The App does not upload PDFs to any server.

## Third-Party Services

If analytics is enabled, Firebase Analytics (Google) processes anonymous usage metrics.

Google Privacy Policy: https://policies.google.com/privacy

## Children’s Privacy

The App is a professional and technical tool and does not target children. No age-specific data is collected.

## Security

Because no personal data is collected or transmitted, privacy risk is minimal. Standard platform security, such as Android and iOS sandboxing, applies to locally stored exported files.

## Your Choices

- Toggle analytics off at any time in the settings section using the “Enable anonymous usage analytics” switch

- Delete exported PDFs manually from device storage if no longer needed

## Changes to This Policy

Material changes will update the “Last updated” date. Significant updates, such as the introduction of ads or new data types, will be disclosed in-app before activation.

## Contact

For questions or concerns, contact: **appsupport187@gmail.com**

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**Summary:** The App is privacy-preserving by default. Analytics is opt-in, anonymous, and minimal. No personal data or raw numeric inputs are collected.