It is extremely important to have ongoing and continuous water quality monitoring programs in watersheds for national water quality assessment in describing the status and trends in the quality of surface and ground water resources draining to international waters and causing major global water quality concerns that may have human health implications. Extensive soil and water quality programs in watersheds also provide a sound and science based understanding of primary effects of best management systems implemented on the landscape in improving the overall quality of major water bodies in a given region/basin. Since World War II, agricultural production has shifted from highly labor-intensive to machine driven and chemical-intensive methods. The use of the latest technology in farm mechanization, plant and animal production systems, and in the production of new chemicals for insect and weed control has resulted in an abundant supply of food and fiber at a relatively low cost. At the same time during the last 25 years, a serious public concern has emerged about the fate of agrochemicals and their impacts on humankind and the environment (particularly in relation to water quality). This concern was further intensified recently with the detection of many agricultural pollutants in the worlds major water bodies through the use of several environmental monitoring programs worldwide. A number of environmental monitoring programs were initiated in the United States to better understand the movement and the degradation of agricultural pollutants in the soilwater- air system. The results of these soil and water monitoring studies indicate that behavior of agrochemicals in the soil and water system is a complex process influenced by hydrologic and geologic conditions of the region, chemical properties and agricultural production practices. Development of sustainable agricultural production systems will be necessary to safeguard the worlds already damaged ecosystem and water supplies and sound principles of science and technology will need to be applied to minimize environmental degradation. Many technologies are now available to increase the efficiency of machines, nutrients, pesticides, and irrigation water use by adopting appropriate farming systems but the positive role of these technologies on water quality can only be documented by implementing sound soil and water monitoring techniques in watersheds so that good water quality data are collected to assure that nations water supply are safe for human and animal consumption.