THE DIMINISHED FLOW OF THE ROCK RIVER IN 

 WISCONSIN AND ILLINOIS AND ITS RELATION TO 

 THE SURROUNDING FORESTS. 



INTRODUCTION. 



The purpose of the investigation the results of which are here pre- 

 sented was to ascertain the principal factors upon which the flow of 

 the Rock River depends, to determine the relative importance of each, 

 and, if possible, to discover any practicable means of increasing- the 

 flow or equalizing" the volume of the river. The study includes a con- 

 sideration of the geology of the region, the recent fluctuations in the 

 rainfall, the effects of the artificial drainage of swamps and fields, and 

 the manner in which forests influence the water flow, and aims not 

 only to explain the decreased water flow in the Rock River region, but 

 also to throw light on the relation of forests to water supply in general. 



The local impression is that for some years past the Rock River has 

 been decreasing in volume, or at least changing in the regularity of its 

 flow. In summer the upper tributaries and smaller creeks have occa- 

 sionally run dry. Should these changes continue, they would inter- 

 fere with various industrial interests of the region. Numerous mills 

 and other manufacturing plants in the towns along the river depend 

 upon its water power. There are also dams and locks for slack-water 

 navigation at the principal cities. A canal that extends across the 

 State of Illinois from the lower end of the Rock River to the Illinois 

 River draws upon the Rock River for a part of its water supply. 

 Moreover, the agricultural interests of southeastern Wisconsin, includ- 

 ing extensive cultivated and pasture lands situated among the numer- 

 ous headwaters and smaller tributaries of the Rock River, rely to 

 some extent upon these sources for sustained moisture in the soil, 

 particularly during seasons of irregular or diminished rainfall. These 

 various industries — manufactures, transportation, and agriculture — 

 are closely dependent upon a steady water supply, and therefore upon 

 the forest, which is an agency of the first importance to this end. 



Besides their importance as an agency in regulating the water flow, 

 the forests of the Wisconsin watershed add to the attractiveness of the 

 region, which is annually visited by many people because of its beau- 

 tiful scenery and the excellent fishing" and shooting it affords. 



