Excerpt from The Effects of Regulated Lake Levels on Beaver in Voyageurs National Park, MinnesotaThe present water management is under the control of the International Joint Commission (ijc), the organization responsible for managing waters shared by the United States and Canada since its formulation in 1909. Under the present water management system water levels are kept within a band of acceptable values for certain times of the year, called a rule curve (fig. The present rule curve encompasses a range of maximum and minimum values allowing some leeway in water levels. The general yearly pattern begins in June when high water is reached about a month after natural dates (mid-may), and remains largely stable throughout the summer. In September water levels gradually decline, continuing through the winter and reaching the lowest level from mid to late March (fig. Much of the yearly fluctuation (2 meters) occurs in winter.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.