General objectives of this study are to assess the probable effects of project construction and operation on water quality in local streams and lakes; to ascertain the benefits or harm resulting from changes in water quality, and finally to examine the need for regulation of streamflow for the purpose of water quality control in the principal streams affected. Need for regulation of streamflow was studied not only in light of present conditions, but also under anticipated economic development of the years 1985, 2010, and 2060. Project developments will affect all or part of seven counties in north central Utah: Salt Lake, Utah, Juab, Wasatch, Duchesne, Summit, and Uintah.