Book excerpt: McIntyre's work explains the legal means by which requirements of environmental protection influence the determination of a reasonable and equitable regime for allocating rights to riparian states to utilize shared freshwater resources. The work examines the means and processes by which environmental considerations can act upon the operation of the principle of equitable utilization. The volume provides a comprehensive analysis of the subject, outlining the development, scope and operation in general and customary international law of key rules of environmental protection.