Introduction

Floods are among the most devastating natural disasters, causing loss of life, property damage, and environmental destruction. A Smart Flood Monitoring System uses sensors and IoT technology to monitor water levels in rivers, dams, or low-lying areas in real time.

The system alerts authorities and residents early, enabling timely preventive actions and reducing flood-related damages.

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Objective of the Project

• To monitor water levels in real time
• To send early warnings before flooding occurs
• To enable remote monitoring via IoT
• To support disaster management and minimize damage

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Working Principle

1. Water level sensors detect the depth of water
2. Microcontroller reads the sensor data
3. If water exceeds a preset threshold, buzzer and alarm are activated
4. Data is sent to cloud via Wi-Fi for remote monitoring
5. Optional: SMS or mobile app alerts to residents and authorities

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Components Required

• ESP32 / NodeMCU (ESP8266)
• Water Level Sensor / Ultrasonic Sensor / Float Sensor
• Buzzer / Alarm
• Relay Module (optional for gates or pumps)
• Power Supply
• IoT Platform (ThingSpeak / Blynk / Firebase)

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Block Diagram

Water Level Sensor
          ↓
      ESP32 / NodeMCU
          ↓
     Buzzer / Relay
          ↓
         Wi-Fi
          ↓
     Cloud Platform

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Circuit Connections (ESP32 Example)

Ultrasonic Sensor (HC-SR04)

VCC → 5V
GND → GND
Trig → GPIO27
Echo → GPIO26

Buzzer

+ → GPIO25
- → GND

Relay (Optional Pump/Gate)

IN → GPIO33
VCC → 5V
GND → GND

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IoT Arduino Code (Smart Flood Monitoring System)

#include <WiFi.h>
#include "ThingSpeak.h"
#include <NewPing.h>

#define TRIG_PIN 27
#define ECHO_PIN 26
#define MAX_DISTANCE 200 // cm
#define buzzer 25

WiFiClient client;
unsigned long channelID = 123456;
const char* writeAPIKey = "YOUR_API_KEY";

const char* ssid = "Your_WiFi";
const char* password = "Your_Password";

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);

void setup() {
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }

  ThingSpeak.begin(client);
}

void loop() {
  delay(1000);
  unsigned int distance = sonar.ping_cm();

  Serial.print("Water Level Distance: ");
  Serial.println(distance);

  // Threshold for flood detection
  if (distance < 20) { // Less than 20 cm from sensor = high water
    digitalWrite(buzzer, HIGH); // Alert
  } else {
    digitalWrite(buzzer, LOW);
  }

  // Send data to cloud
  ThingSpeak.setField(1, distance);
  ThingSpeak.writeFields(channelID, writeAPIKey);

  delay(15000); // Update every 15 seconds
}

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Code Explanation

• Ultrasonic sensor measures water distance from top of sensor
• ESP32 compares distance with threshold to detect flooding
• Buzzer alerts locally if water level is high
• IoT cloud provides remote monitoring and logging

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Advantages

• Early flood warning system
• Real-time monitoring
• Can prevent property damage and save lives
• IoT-based remote accessibility

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Applications

• River and dam monitoring
• Urban low-lying areas
• Industrial flood prevention
• Smart city water management

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Future Enhancements

• SMS or app notification alerts
• Automatic water pump activation
• AI-based flood prediction
• Integration with municipal emergency systems

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Conclusion

The Smart Flood Monitoring System is a critical project for disaster management and smart city solutions. By using IoT and sensors, it provides real-time monitoring, early warning, and quick response, minimizing flood-related damages.