Human beings are the main reason for the contamination of water.  Contributions to water pollution include  chemical fertilizers and pesticides, runoff from septic tanks, outflow from livestock feedlots, chemical wastes (some toxic) from industries,substances drawn from the air (see acid rain), silt from soil erosion, and sewage and other urban wastes from cities and towns. Water pollution alters both environment and human health directly as it can contributes in  biodiversity losses and can also cause various diseases in humans. Along with this water pollution also causes disturbances in aquatic habitats of aquatic creatures.

Currently, about 40 percent of the world’s population is facing water scarcity and 1.7 billion are living in river basins where water usage exceeds renewal. Without immediate action, it is estimated that by 2025 half of the world’s population will be experiencing a water shortage, and by 2050 one in four people will be living in a country with an insufficient fresh water supply. Considering these facts and estimation, we must focus on controlling  water pollution. Water pollution can be controlled by throwing wastes and sewage at proper places, by avoiding use of any forms of chemicals substances near water resources, by using Eco friendly products, by planting trees near w.sources, etc. As being the most civilized creature of planet we humans must be responsible for our doings and act accordingly.

Water Pollution is a big problem here in Nepal. People throw wastes, non-degradable materials especially in various water sources. Bagmati river, which is in the bank of Kathmandu City is one of the most polluted river of Nepal. Despite cleanliness campaign organized at regular interval, we are unsuccessful in changing people's perception towards Water Pollution.