Web server, Reset button. Can someone check my code please!

 const int floodSensor1 = 2;     // the number of the Flood Sensor pin
 const int floodSensor2 = 3;     // the number of the Flood Sensor pin
 const int floodSensor3 = 4;     // the number of the Flood Sensor pin
 const int floodSensor4 = 5;     // the number of the Flood Sensor pin
 const int floodSensor5 = 6;     // the number of the Flood Sensor pin
 const int floodSensor6 = 7;     // the number of the Flood Sensor pin
 const int floodSensor7 = 8;     // the number of the Flood Sensor pin

An array would make a lot more sense, and use a lot less code.

   floodSensorState = HIGH;

The flood condition might be true. But, there is no (single) flood sensor, so it's state can't possibly be HIGH. A more meaningful name is in order.

    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        Serial.write(c);
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the http request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          // send a standard http response header

Send a standard response, regardless of what the client asked for. Not a good plan.