FORESTS AND STREAM-FLOW
William S. Harvey
Philadelphia
Professor Willis L. Moore, Chief of the United States Weather Bureau, in his address before the Atlantic Deeper Waterways Convention in Providence, September 1, 1910, made the statement that the waterways were in no way affected by the forests; that he had records made for many years that clearly prove that the waterways have in no way been affected by the acts of man; that he was aware that he would destroy a popular impression by making this statement, and that he based his statement upon the facts as he knew them. The following eminent men in articles published in American Forestry Magazine for April, 1910, take exception to and refute the statements and claims made by Professor Moore (and which he had previously expressed): Professor Filibert Roth, University of Michigan, Forester; Professor L. C. Glenn, Vanderbilt University, Geologist; and Professor George F. Swain, Harvard University, Engineer. These gentlemen represent geology, forestry, and engineering, and their training, knowledge, and experience qualify them to speak intelligently and with authority on this question of the influence and effect forests have upon streams.
Mill owners and operators on various rivers in New England have practical demonstration that denuding or partial denuding of the forests on the head-waters of the stream on which they are dependent for power has seriously impaired the uniformity of flow and lessened the amount of power which they are able to secure for the same number of days in a year: that denuding also allows the rainfall to run off rapidly, causing erosion, which erosion is filling and choking the streams and rivers and in seasons of flood depositing silt in valleys which have heretofore been of agricultural value, thus largely impairing or destroying their fertility. This condition equally applies to various streams and rivers in other sections of the United States. It is moreover denied and refuted by the greatest financial and manufacturing interests, who have spent and are spending hundreds of millions of dollars in the development of electric power on the waterways of the United States. They have in their employ the most competent engineers known, who have investigated the entire situation, studied the maximum and minimum rainfall for a long period of years, and conditions influencing the territory embraced on the streams and rivers upon which they propose to make and are making and have made developments. These great interests, vital to commerce and trade, emphatically state that the flow of streams is affected by the forest cover, and that they are most anxious and are earnest in efforts to have the forest cover protected in all territory in which they operate, claiming that if the hillsides or mountains on the headwaters of water-sheds are denuded the volume of power will be so diminished, impaired, or destroyed that the value of the bonds issued for the development of these powers, and heretofore considered one of the safest and most desirable investments, will be seriously imperilled.
In addition to the authorities above named, and to whose articles I have referred, there are others who have refuted and contradicted Professor Moore from his own premises and data. His Excellency M J. J. Jusserand, Ambassador from France, publicly stated the absolute principle: "No forests, no waterways." Without forests regulating the distribution of water, rainfalls are at once carried to the sea, hurried sometimes, alas! across the country. After having devastated the neighboring fields, the rivers find themselves again with little water and much sand; and with such rivers, how will you fill your canals?
The question is as clear as can be; do you want to have navigable rivers, or do you prefer to have torrents that will destroy your crops and never bear a boat? If you prefer the first, then mind your forests. If the Mississippi is the "Father of Waters," the forest is the father of the Mississippi. The French Ambassador, you will note, says, "We can tell you, for we know. France is now spending many millions of dollars to reforest the mountain-sides denuded many years ago, which have seriously affected her waterways."
Some of us feel it is unwise to take too seriously all the deductions and predictions that are made by academic, scientific, idealistic theorists, especially if the department of science with which they are most intimately identified relates almost exclusively to atmospheric conditions, which are still so imperfectly understood that they not infrequently elude prediction; though where the results of scientific deductions are proven correct and add to the fund of knowledge, they are deserving of our greatest respect and regard. We have much confidence, for example, in the conclusion of Gifford Pinchot and his staff of assistants, who have made a practical as well as scientific study of the effect of forest cover on the flow and supply of water in streams, which conclusions unqualifiedly refute the statements made by Professor Moore.