Amanzi - Know Your Water

This is a submission for the DEV Weekend Challenge: Community The Community South Africa...

This is a submission for the DEV Weekend Challenge: Community

The Community

South Africa is in a water crisis that has taken many years to manifest into daily life.

I live in the Johannesburg area, where water is not something you take for granted. Gauteng imports nearly 98% of its water from outside the province, the Vaal Dam fluctuates dangerously, and municipal restrictions can change overnight. In townships like Alexandra and Diepsloot, flooding and water outages are a lived reality, not a news headline. Nationwide, 47% of South Africans experience regular water disruptions, and the country loses an estimated 35% of its treated water to leaking infrastructure before it ever reaches a tap.

Yet for the average resident, getting reliable, consolidated water information means digging through the Department of Water & Sanitation's PDF reports, checking three different municipal websites, and hoping the news covers it. There is no single, accessible, community-facing app that brings it all together.

The community I built Amanzi AquaSA for is every South African who has ever woken up to no water and/or tried to figure out whether they can legally fill their borehole in a Level 2 restriction area. That's a community of tens of millions of people and they deserve better tools.

What I Built

Amanzi AquaSA is a Flutter mobile app (Android & iOS) that turns South Africa's fragmented water data into one clear, beautiful, and genuinely useful experience. The tagline is simple: Know Your Water.

The app is organized into five core areas:

Dashboard - A live at-a-glance summary of national water health. Dam levels, active restrictions, rainfall this month vs. historical average, and a critical alerts banner if something urgent is happening in your area. It answers the question every Gauteng resident asks on a dry summer morning: "How bad is it today?"

Dams & Rivers - Detailed profiles for South Africa's 10 major dams (Vaal, Sterkfontein, Gariep, Theewaterskloof, and more) with historical level charts you can switch between 1-year and 10-year views. River health cards cover the Vaal, Olifants, Limpopo and other major waterways - including honest pollution and health status ratings. Catchment area maps show where the water actually comes from.

My Water Usage - A personal water calculator that lets you tally your real daily usage: glasses of water, coffee, shower minutes, toilet flushes, laundry loads, geyser, garden watering and more. It compares your total against the SA average (237L/day) and the humanitarian minimum (50L/day), estimates your monthly municipal bill, and gives you targeted tips based on where you're using the most.

Alerts - A filterable feed of water alerts: flood warnings, restriction level changes, dam level thresholds, quality advisories, and maintenance outages. Critical alerts surface across the whole app with a pulsing red banner so nothing urgent gets missed.

Explore - The bigger picture. National water infrastructure entities (Rand Water, Umgeni, Lepelle), active government water projects with budgets and timelines, dam levels by province, and an educational self-sufficiency hub covering borehole drilling (process, costs, legal requirements), DIY water treatment methods (UV, RO, ceramic filters, SODIS), and desalination techniques from emergency solar stills to municipal-scale reverse osmosis.

An interactive map ties it all together; toggling between dam markers, river health overlays, catchment area polygons, and flood-risk zones across the country.

Demo

Video demo link

APK Download

Code

Github Code

How I Built It

Amanzi AquaSA is built entirely in Flutter, targeting Android and iOS from a single codebase. Here's the technical breakdown:

Framework & Language Flutter 3.x with Dart, using a feature-first folder structure. Each feature (dams, rivers, rainfall, etc.) is fully self-contained with its own models, repository, and screen files - making the codebase easy to extend as live APIs become available.

Navigation go_router for declarative, URL-like routing with deep linking support - important for eventually sharing direct links to specific dam or river detail pages.

Maps flutter_map with OpenStreetMap tiles (no API key, no cost, works offline). Custom CustomPainter layers for catchment area polygons and color-coded river polylines. Dam markers are dynamically colored by level percentage - teal for healthy, amber for low, red for critical.

Charts fl_chart powers the historical dam level line charts, monthly rainfall bar charts, and the usage history graph. The dam detail screen supports switching between 1-year and 10-year data views with smooth animated transitions between datasets.

Usage Calculator Built with stateful widget steppers and a real-time litre accumulator. Toilet flush mode toggles between old (9L) and new (4.5L) cistern volumes. Shower time uses a Slider rather than a stepper since duration is continuous. Results are persisted locally with shared_preferences to show a 7-day usage history.

Self-Sufficiency Hub The rainwater harvesting calculator uses a simple formula: roof area (m²) × rainfall (mm) × 0.8 efficiency = litres collected. Users input their roof size and select their region's monthly rainfall to get a realistic monthly collection estimate - surprisingly powerful for planning tank sizing.

Water security isn't a future problem in South Africa - it's today's problem, and it's getting harder to ignore. Amanzi is a small piece of infrastructure for a community that needs better tools to understand, track, and protect the water they depend on.

Know your water.