Online Water Billing System

info 1. Project Overview

The Water Billing System is a web application designed for Local Government Units (LGUs) to manage the complete billing cycle of water utility services.

• Customer Management
• Bill Generation from meter readings
• Payment Processing and Credit Handling
• User Role Administration

Built entirely on Google Workspace, it utilizes Google Sheets for storage and Google Apps Script for logic.

developer_mode 2. Technology Stack

🔧 Backend

• Google Apps Script (JavaScript-based)
• Runs on Google Cloud (serverless)

🎨 Frontend

• HTML5, CSS3, JavaScript (ES6+)
• Chart.js, Material Icons, Google Fonts

📊 Database

• Google Sheets with structured tabs (Customers, Users, Bills, etc.)

🔄 Communication

• google.script.run for async frontend/backend calls

architecture 3. System Architecture

• Client: SPA using HTML, CSS, JavaScript
• Server: Google Apps Script (Code.js)
• Data Storage: Google Sheets with SpreadsheetApp

Execution Flow:

1. User opens the web app
2. doGet() loads the UI
3. Login checked via validateLogin()
4. Frontend makes all future calls via google.script.run

star 4. Key Features

👥 4.1 User & Session Management

• Secure Login & Role-Based Access Control
• Full user CRUD + system lock and fullscreen support

👤 4.2 Customer Management

• Manage customer data in Customers sheet
• Add, update, delete, search and filter customers

🧾 4.3 Billing Management

• Create bills based on meter readings
• Auto-fetch previous reading
• Real-time calculations using customer-specific tiered rates
• Duplicate bill prevention

💵 4.4 Payment Processing

• Multi-bill payments and surcharge logic
• Auto-apply credits and handle overpayments
• All payments logged in the Payments sheet

📈 4.5 Reports & Analytics (UI Disabled)

• Available backend functions to generate reports
• Includes revenue tracking, overdue analysis, trends