This article discusses Part 5, determination and prediction of the behavior of water quality in impoundments, of the Public Law 660 research mandate. The objective of this mandate was to establish streamflow regulation systems that would provide for impounding water during times of high streamflow and releasing the water at times of low natural streamflow. Such releases would supply additional water downstream and would serve to alleviate any downstream water quality problems. From the large number of possible research projects, five were chosen by the engineering section at the Taft Center for initial investigation: simulation of impoundments on a small scale; dissolution of iron and manganese; studies on the dissolved‐oxygen budget; artificial destratification of impoundments; and, biologic transformation of nitrogen. The article discusses two of the projects that have progressed sufficiently to permit the presentation of some preliminary data, small‐scale simulation and nitrogen transformations.