Solar desalination is suitable and cost-effective method to achieve clean water for drinking purpose in coastal region. A solar still works on a basic principle of water distillation which needed solar radiation as the main heat source. The evaporation results in separation of the water vapor from impurities present in the saline and pollutant water inside the basin. But the low distillate of solar still is a big concern. In present study, the solar still has been modified by integrating it with external heat source. The impact of water depth of solar still on the distillate output has been investigated. The thermal efficiency of solar still has been modified by integrating it with solar pond as external heat source. It has been found that the water depth greatly influenced the performance of solar still. The maximum distillate productivity has been obtained with 5 cm depth of water.