This country has suffered from many great floods in past years, but none so awful in its scope and terrible consequences. The present calamity must bring the country to its sober senses and make us see the positive necessity--the inevitable MUST--of taking immediate and adequate measures to guard against the repetition of such a disaster. "Strike while the iron is hot," has been the battle-cry of men of action throughout the world! And today, while the iron of adversity is hot in the bosom of the Republic, is the time to strike upon the ideas that are to make the heroic surgery of healing. What is the remedy for these mighty floods that are sweeping and ruining the interior country? Beyond the supreme consideration of the loss of life they are the financial tragedies of the century. They occur at rare intervals in Ohio and Indiana and in New York. But in the valley of the Mississippi and in the Ohio Valley they are almost an annual or bi-annual scourge of waters, terrific in suffering and appalling in cost. NOT A QUESTION OF COST No expenditure of public money is too great that will strengthen the defenses of the people against the giant forces of destruction in the Mississippi and Ohio Rivers. No cost in national expenditure for permanent defense against such catastrophes would approximate the cost in a single decade to the pockets of the people, not to speak of the uncountable value of human life. Governor Cox, of Ohio, estimated that the damage in Ohio alone by the recent floods was more than $300,000,000--nearly as much as the cost of the Panama Canal. The total cost of the recent flood is vastly greater than that of the Panama Canal! The American Government can no longer stop to consider money in dealing with the problems of internal economy and of elemental humanity. The floods create an emergency as definite and imperative as war. It is time now to start some movement for the preservation of life and property against such occurrences. MEASURES AGAINST REPETITION OF DISASTER It is not the mission of this book to prescribe plans for meeting the situation. That must be the work of a corps of trained engineers who shall study the whole problem comprehensively and in detail. Rather it is our purpose here to bring home the overwhelming need for prompt action. We may be permitted, however, to point in a general way, and on high authority, the general lines that the necessary remedies must take. The river problems in the great central valleys present certain difficulties which engineers have been unable to overcome. If levees are constructed, it is found that the bed of the stream rises also, so that the situation is not materially changed. If channels are deepened, the fury of the floods is increased. If the construction of reservoirs is proposed, there are very important questions of location and danger. UTILIZING NATURAL RESERVOIRS