In many occasions severe water leakage problems are faced in shotcrete lined or unlined water tunnels that not only reduce stability of the rock mass but also result in loss of valuable water in conveying tunnel systems. Such leakage causes safety risks and increases the potential for huge economic loss to the hydropower projects.

Heavy metals are one of the prominent sources of pollution in industrial wastewater and excessive presence of these metals is causing severe health and environmental problems.

Pakistan is subjected to rapid water shortage due to different social and environmental problems. Moreoer, the drinking water is being contaminated at an alarming rate that is mostly due to the discharge of untreated domestic and industrial effluent and agricultural run-off.

The disposal of untreated industrial effluent into receiving water courses has become a major environmental challenge being faced by most of the developing countries. In Pakistan numerous industrial units that dispose their effluent directly into receiving stream without any treatment.

On September 20, 1996 an overwhelming 96.5% of the members present at the Joint Session of the Nepalese Parliament hurriedly ratified the Mahakali Treaty to fulfill the requirements of the Article 126 of the 1990 Constitution of Nepal.

This paper generally describes the background of global hydropower CDM projects and the development of Small Hydropower (SHP) CDM projects in China. It analyses the features of China SHP CDM projects, and summarize their prospects and future challenges.

The process of finding optimal solution for utilization of hydro-energetic potential of a river flow is a very complex procedure, because it is necessary to find a compromise between an energetically optimal solution and a solution with lower negative influence on the environment and sociological conditions, which is often contradicatory in practice.

Ungauged basins are challenges for hydrological study, the key discipline to analyse for planning and the operation of water resources projects. Several river basins have no hydrologic measurements where there is feasibility of promising water resources schemes.

Energy is the engine of growth of any developing economy. Consumption of electrical energy is universally accepted indicator of progress in the agriculturall, industrial and commercial sectors, as also of the well being of the people of the nation.

Large-scale promotion of small scale decentralized renewable energy technologies to achieve a part of millennium development goal remained a great challenge until recently.