Low-Cost Water Level Indicator Using Logic Gates for Enhanced Water Management

Water scarcity and tank overflow pose significant
challenges in urban Bangladesh, leading to substantial water
wastage. This paper presents a cost-effective water level indicator
designed for domestic water management, utilizing a single IC
74HC04 NOT gate, two BC547 transistors, LEDs, and resistors.
The system leverages water’s conductivity to detect mid and
upper water levels, providing visual indications via LEDs at a
total cost of approximately 300 Taka ( 2.46 USD). Compared to
alternative solutions like ultrasonic sensors ( 1200 Taka) or float
switches ( 950 Taka), the proposed design offers a 3–4 times cost
reduction, making it accessible for low-income households and
educational applications. Implemented on a portable breadboard
setup, the system ensures reliability, with stable LED indications
verified through experimental testing. This work provides a simple, affordable solution tailored to resource-constrained settings,
promoting efficient water management in urban environments.