This paper is a review of environmental protection of water resources from pollutants and includes eight chapters: introduction, types of water resources, pollutants, biodegradation, environmental protection, effect of climate and environmental changes, conserving water resources and conclusion. Each chapter is separated. Water resources occupy a special place among other natural resources. Water is the most widely distributed on our planet: albeit in different amounts, it is available everywhere and plays a vital role in both the environment and human life. Of most importance is fresh water. Human life itself is impossible without it because it can be substituted by nothing else. Pollution of the environment has been one of the largest concerns to science and the general public in the last years. Biodegradation can be used to remove or to transform pollutants found in the environment, dissolved in natural bodies of water, into harmless compounds. To avoid further water problems and lessen projected harsh outcomes for the future we must conserve water and energy, and protect land and biological resources that are vital for a sustainable economy and environment