THE OHIO FLOODS.
BY THE HON. GEORGE E. JENKS.
Several causes are assigned for the excessive rise of water in the Ohio valley. This water-shed is accredited with an area of two hundred thousand square miles, and it lies upon the border-line of hot and cold temperatures. It is subject to heavy storms, and sometimes, in winter, to large accumulations of snow. It is presumable also, the rainfall is greater than the average of the country. When, following great deposits of snow, warm, heavy, and prolonged rains occur, excessive floods must be the result. Add to these coincidents the fact that forests, once existing, are now so nearly annihilated that little protection is offered against a rapid dissolution of the snow, and the sudden freezing of the earth in an interval of the late storm preventing absorption of rain falling thereafter. The waters thus produced fall into the main streams without hindrance, like rain from roofs of buildings. An aggregation of waters in this valley, rising from fifty to seventy- one feet, is of annual occurrence, intensified according to excesses and completeness of coincidents.
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The damage arising from the Ohio flood of 1882 has been estimated at twelve millions of dollars; that of 1883 at thirty-five to forty millions of dollars. If these estimates are approximately correct, what must have been the damage from the flood of 1884!
There are other causes for the floods in the Ohio valley, and in all Southern streams, that have been but little considered, which exercise undoubted and immense influence in solving the peculiarities of the question under consideration, and afford striking contrasts in different sections of this country.
There are two water systems presented in North America. North of about the forty-first degree of latitude probably the southern limit of the once glacial region--a reservoir system prevails toward the headwaters of all the streams. It includes New England, New York, Michigan, Wisconsin, Minnesota, Dakota, and to the Rocky Mountains divide, and all of the British Provinces to the Arctic Circle. It also somewhat occurs on the western slope of the Rockies. This region is notable for the great lake system, and the immense number of smaller lakes and ponds--natural inland reservoirs, supposed to be largely of glacial formation to hold back considerable portions of the cumulative waters upon any given water-shed, and serving to restrain the outflow, even after they are filled. These basins exercise a happy and protective influence in many ways.
South of the forty-first parallel, the rivers have no reservoirs to hold any part of the flow from their water-shed. Within this vast area few lakes or ponds exist. The superabundance of water has no restraint, but at once takes to the bottom lands. To this southern system the Ohio River notably belongs, with all its tributaries. Within its two hundred thousand square miles of area, scarcely a natural reservoir is to be found. No other part of the country is so devoid of basins. Its feeders drain the western slopes of the Alleghany and Cumberland Mountains--Western Pennsylvania and West Virginia, representing sixty thousand square miles, the southern portions of Ohio, Indiana, and Illinois, and most of Kentucky and Tennessee. These States are without lakes or ponds. Nothing intervenes to hold back any portion of the vast flow from these coincidents of nature before spoken of, and therefore the excessive floods of last year and this. Such results must continue to follow.
During the summer droughts the other extreme prevails. For lack of a reservoir system to withhold and control the flow of water, the river falls from flood-tide--seventy-one feet--to points so low as to seriously impede or prevent navigation. Sometimes even the smallest steamers and barges fail to pass between Pittsburgh and Cincinnati, and coal famines have not been unfrequent, resulting from difficult navigation. An equable flow of this stream is impossible. It will always be subject to these extremes. Nothing but an extensive method of filling or diking is likely to prevent the inundation of cities and villages that are not seventy feet above low-water mark, with attending suffering and destruction of life and property. All Southern rivers are liable to like extremes.
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In contrast, it may be noted that the St. Lawrence River but slightly varies its flow, above Montreal, because of the restraining power of the Great Lakes, its feeders. The upper Mississippi rises not to excess because of the thousands of lakes and lakelets in Wisconsin, Minnesota, and Dakota, its sources. The floods occur in its southern portion, chiefly below St. Louis. But for this reservoir system its navigation in the upper portion would be seriously impeded in summer seasons.
Disastrous floods can scarcely occur on the St. John's, St. Croix, Penobscot, Kennebec, Androscoggin, Saco, Piscataqua, Merrimack, Connecticut, or Hudson Rivers, except from damming of the ice in winter or springtime (and that cause is of rare occurrence), such is the elaborate system of reservoirs about the headwaters of these streams. This northern country is greatly benefited by these excavations occurring from geological causes.
The Merrimack River has a water-shed of about four thousand square miles miles--one fiftieth part of that of the Ohio. It has the Winnipiseogee, Squam, and Newfound Lakes, and hundreds of ponds to fill, that store a large amount of water, before any considerable rise can take place in the river, and then they restrain the flow. No excess of water comes through the Winnipiseogee River, though it is the outlet of a water-shed nearly as great as of the Pemigewasset. The freshets of the Merrimack come chiefly from the last-named stream and minor tributaries. Without these reservoirs, the manufacturing establishments at Lawrence, Lowell, and Manchester, would cease to be operated by water-power during the summer droughts. The highest flow of water in the Merrimack known in forty-six years, as measured at the Lowell dam, was thirteen and seven-twelfths feet. This occurred in 1852. Only a few times have freshets exceeded ten feet rise over that dam.
The greatest fall of water and rise of the freshet, in this valley, known at Concord, New Hampshire, occurred in August, 1826. This storm notably caused the land-slide in the Saco valley, which buried the Willey family. The next was in early October, 1869, which caused the slide of seventy-five acres of land on the western side of Tri- Pyramid Mountain into Mad River, in Waterville.
Messrs. Rand, McNally, and Company, of Chicago, in their Atlas of the World, give data to illustrate the two river systems of the country spoken of. Names of sixty-seven lakes are given in Maine, and beside these are ponds almost innumerable. By census statistics given, her reservoir and land areas are as 1 to 13. New Hampshire is accredited with three hundred and sixty-two lakes and ponds, being as 1 acre to 41 of land. Vermont has forty-one lakes and ponds, including Lake Champlain, being as 1 acre to 24 of land. Massachusetts, forty- seven lakes and ponds; Rhode Island, forty-seven; Connecticut, eighteen; New York, two hundred and sixty, beside her great lakes; New Jersey, ten; Pennsylvania (chiefly northeastern portion), fifty-eight; Michigan, ninety-eight lakes, and ponds in great number; Wisconsin, seventy- two lakes, and a large number of ponds; Minnesota, one hundred and forty-two lakes, and ponds innumerable; Dakota, fifteen lakes, and a great number of ponds; and Iowa, forty-eight lakes.
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In contrast, Virginia has only Lake Drummond--really a part of the Dismal Swamp; West Virginia, Ohio, Kentucky, and Tennessee, none; Indiana, eleven lakes, and Illinois, eight,--all on northern water- shed. The Carolinas, Georgia, and Alabama have no reservoirs. Lagoons exist in the States bordering the Mississippi River and the Gulf, which are filled by the overflow of the rivers.
A consultation of any good atlas of our country will confirm these statements.
The two sections are thus contrasted. The Northern States have reason to be very thankful for their more equable system, for the motive power its reservoirs furnish, and for exemption from disastrous floods, as well as from cyclones and tornadoes.
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