BlueLedger

Inspiration

The US faces an $8 billion annual funding gap for stormwater infrastructure. Cities offer rainwater capture incentives but rely on costly manual inspections that discourage participation.

What it does

BlueLedger automatically converts captured rainwater into blockchain-verified credits using $10 IoT sensors, eliminating manual inspections and creating a transparent marketplace for stormwater management incentives.

How we built it

We architected a full-stack system with a React dashboard displaying real-time sensor data through WebSocket connections. The Node.js backend simulates IoT sensors generating water level events every 30 seconds, storing readings in PostgreSQL via Drizzle ORM. When sensors detect water release events, our smart contract automatically mints credits on Ethereum Sepolia testnet. We integrated MetaMask for wallet authentication and built municipal-grade interfaces using Tailwind CSS and Radix UI components.

Challenges we ran into

We struggled with integrating real-time sensor data with blockchain transactions while maintaining data consistency. Designing a municipal-grade interface that balances complexity with usability proved challenging. Creating accurate credit minting logic tied to water capture events required careful event handling and state management.

Accomplishments that we're proud of

We built a fully functional system with live sensor simulation, automated credit minting, professional municipal dashboard, and seamless wallet integration in a weekend hackathon timeframe.

What we learned

Blockchain can solve real infrastructure problems beyond finance. IoT sensor integration requires careful event handling and robust error management. Municipal software needs enterprise-grade reliability and transparency to gain institutional trust.

Uniqueness

BlueLedger is the first blockchain solution specifically designed for urban water capture verification. It combines low-cost hardware with transparent smart contracts and directly addresses the $67 billion stormwater infrastructure market gap.

What's next for BlueLedger

We plan to deploy on mainnet, integrate with actual IoT sensors, partner with municipal water departments, and expand to green roofs and permeable pavement verification systems.

Built With

• drizzle-orm
• ethereum-sepolia-testnet
• ethers.js
• express.js
• metamask-integration
• node.js
• postgresql
• radix-ui
• react
• replit
• tailwind-css
• tanstack-query
• typescript
• vite
• wouter
• zod