# ADR 0001: Initial Architecture Decisions

**Date**: 2026-06-19
**Status**: Accepted

## Context

We need a monitoring system for small water systems that is affordable, low-egress, and usable by both non-technical owners and professional operators.

## Decision

We will use a hybrid edge + cloud architecture with:
- Raspberry Pi 5 edge devices
- Tiered telemetry (compressed healthy summaries + rich alert payloads)
- Monitored Objects as the core abstraction
- Hybrid AI (small edge models + larger cloud models)
- Multi-tenant web application with role-based access

## Consequences

- Strong emphasis on local processing to control data costs
- More complex initial onboarding (AI interview + camera mapping)
- Clear separation between Basic (owner) and Advanced (operator) dashboard views

## Alternatives Considered

- Pure cloud SCADA (too expensive for small systems)
- Fully on-prem with no cloud (loses multi-system operator view and easier updates)