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MEASURE OF FLOOD CONTROL

R

EGNAULT, in his book on "Deforestation and Decadence," paints a vivid picture of the effects of deforestation.

"When the mountains are deforested all is ruined. The rains . . . fall in torrents and rush off the denuded soil. They first carry off the vegetable cover. The mountain shows its rocky skeleton, the rocks break up, cones of erosion are formed, landslides, gullies, unstable slopes become so many running sores by which the substance of the mountain is carried down. The rocks offer more or less resistance according to their texture, but none withstand. Even granite splits up into enormous blocks which roll irresistibly down the valleys. . . . When the highlands are ruined, what becomes of the plain? . . . The river becomes a torrent when it rains, carrying down earth, trees, and rocks. Swollen beyond measure, it flows over the plain in a sudden flood which destroys houses, flocks, villages, and people. . . . The sudden flood is characteristic of denuded countries . . . the mountain can no longer supply the valley with water. Now is the time of drought and famine."

France, through bitter experience, has learned the lesson of deforestation of mountains. Other countries, such as Palestine, Assyria, Arabia, Greece, Tunisia, Algeria, Italy, Spain, Persia, Siberia, Dalmatia, all bear the same evidence of deforestation. In 1860, France, after terrible floods of 1856 that ravaged the valleys of the Rhine, the Loire, the Rhône, the Garrône, and the Seine and caused the loss of a great number of lives and did damage amounting to more than $38,600,000, passed the first law on the reforestation of the mountains. Since then and up to about 1913, some 500,000 acres have been acquired and more than one-half of the land has been planted. Already 163 of the mountain streams have been entirely controlled and 654 are beginning to show the controlling effects of the forests upon their watersheds. Thirtyone of the mountain streams now entirely controlled were considered hopelessly bad half a century ago. Two principles underlie the control of erosion in the mountains, first, to stop the earth from moving as a whole, and, second, to cover it with shrubs and forests. A remarkable example of the control of a mountain stream, which did a great deal of damage from 1832

France

to 1847, is found in La Grollaz. The reforestation work was started in 1880. Today, the stream is a pretty brook with waterfalls over artificially constructed cement dams, protected by a dense cover of alder, which holds the soil immediately along the brook. Further up from the stream, pine has been planted with the result that this mountain stream today looks pretty much like a New England trout stream, bordered by trees 50 feet in height. It is expected that $50,000,000 will be spent before the work of reforesting the mountain slopes for protection is completed.

Three-fourths of the forests of Switzerland are regarded at the present time as protection forests; that is, they are located in the basins of torrents, where they serve to lessen the harmful effects of run-off, or they afford protection against avalanches or against severe climatic conditions. Since

the maintenance of such forests is conceded to be essenSwitzerland tial to the general welfare, federal laws have been in force since 1876 which forbid cutting except with the consent of the forest administration, and as a rule clean felling is forbidden altogether. The effect of these provisions has been very satisfactory, the area of protection forests has been maintained and increased, and the people have in general been well disposed toward the matter; so much so that in 1897 a popular vote extended the application of the idea of "protection forests" to include not only the Alps, but also the Jura and some portions of the plateau region.

In Austria, before the war, a law for reforesting mountain slopes based on that of France was passed in 1884 to control mountain streams. This law carried an annual appropriation of $100,000. For Austria the regulation of the lower portions of the rivers, $1,350,000 was appropriated at the same time, and of this sum $400,000

has been expended on reforestation.

In Russia, before the war, over 100,000,000 acres of forRussia ests have been classed as protection forests, or forests which are indispensable to control of stream flow.

Japan

Japan has close to 2,000,000 acres of forests specifically designated to prevent denudation of soil and occurrence of floods, embracing some 353,000 separate forest areas.

The disastrous effects of deforestation of the mountains in Italy—a country of mountains-are particularly striking. Small streams in the Alps, the Apennines, the Abruzzi mountains and also the mountains of Sicily and Sardinia, swelled by rain and the thawing of snow into turbulent torrents and no longer restrained by forest vegetation, rush down with tremendous

force and cover agricultural land with sand and stones, causing the Italy owner enormous and very often irreparable loss. In 1877, the

first law for maintaining protection forests was passed. It was not, however, until the passage of a new law in 1910 that made obligatory upon communities and private owners reforestation of denuded areas in the mountains that rapid progress was made. To carry out the provisions of the 1910 law, the government appropriated for the first five years about $8,000,000. A large part of this expenditure is for the purchase by the government of forests in the mountains, as well as of areas in need of reforestation.

In Spain in 1908 a law was passed for the conservation of forests situated in flood areas and in other places where the permanence of Spain the forest is essential as a preventive against erosion and rapid surface run-off.

Can the United States learn nothing from these painful experiences of the older countries?

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By JOSEPH S. ILLICK, State Forester of Pennsylvania,

and E. F. BROUSE

SERIOUS drought was general throughout Pennsylvania during the late summer and fall of 1922. It prompted the Department of Forestry to make a survey of the situation to determine practical and effective measures for future relief work. The result of the investigation, as stated in the following paragraphs, indicates the value of the forest in preserving water and in affecting stream flow.

These facts are worthy of consideration by any student of methods to prevent floods.

An official of a water company stated that during previous droughts of the last twenty-five years there was at least three times as much water in the reservoirs as during the drought of 1922. All the factors influencing water production appear to be similar to those of former years except that a more incomplete and inferior forest growth now covers the watersheds.

Forests
Conserve
Springs

Lumbering operations have cut off all the large timber, and forest fires have repeatedly burned over the hillsides and consumed what the lumbermen left and most of the young growth that followed the lumbering operations.

Twenty years ago a total of 250,000 gallons of water flowed from a spring near Ashland. During the drought 50,000 gallons flowed from it, that is, only one-fifth as much as twenty years ago. Twenty years ago, when considerable timber was left, there were seventeen springs feeding the reservoir. Now only seven of these springs are flowing and several of these are very low. During these two decades all the timber has been cut, and forest fires have repeatedly burned over the land. A spring known by many inhabitants not to have been dry in the last thirty-seven years stopped during the drought of 1922. It is the belief of those who know the region best that this is the first time that it ever ceased flowing.

Figures show that the water level in the largest industrial reservoir (Queenahoning Dam of Cambria Steel Co.) in the state was very low in 1922. The drainage basin covers an area of 59,000 acres. About fiveeighths of the drainage basin consists of farm and waste land. The forest growth on the remaining three-eighths is rather complete and satisfactory. The average age of the forest trees, which are chiefly hardwoods, is thirty

years. The normal intake of the reservoir is seventeen times greater than the intake during the 1922 drought.

Of nine large water companies in the anthracite coal region, three had no reserve supply for household use or fire protection during the drought of 1922, three had a very small reserve supply, and three had an almost normal supply. It is a significant fact that the last three had drainage basins that were well covered with a forest growth, while the watersheds of the other six were covered with a poor and broken forest growth that had been repeatedly burned over by forest fires.

In all instances where the water became extremely low, it was unfit for human consumption without being boiled, and did enormous damage to industrial plants because of its high acid content. The people and industries were not the only sufferers from the poor quality of the water, for fish and other animal life also suffered greatly. The smaller creeks and rivers were contaminated to such an extent that fish were killed by the thousands. The actual cost of the drought is very hard to estimate. Few industries operating in the regions where the drought was most severe escaped from its evil effects. Coal production was reduced in both the anthracite and bituminous regions. Water had to be hauled in tank cars for many collieries. This was the only way to avoid a shutdown. In some regions it was also necessary to haul water for the operation of railroad engines.

Forests
Affect
Drainage

The municipal water company of Altoona, in addition to its own consumption of 4,250,000 gallons, supplied daily 3,500,000 gallons to a railroad company and 500,000 gallons to another water company. This consumption is nearly twice greater than normal. On January 1, 1923, there was a four-month supply on hand at the present rate of intake and output. The drainage basin extends over an area of about 5,000 acres and is covered by a good forest growth, consisting chiefly of mixed hardwoods, and conifers having an average of about thirty years. This basin has not been burned over in recent years, and shows clearly and convincingly that a good forest cover on a watershed is of great value.

The Girard Water Company of Pottsville has done much forest preservation, forest fire prevention and forest tree planting work on their drainage basins. It was in a position during the drought of 1922 to supply water to many industries of the Anthracite Region. Seventeen collieries, in addition to many regular consumers, were able to operate solely because of the water supply obtained from this company. While their storage capacity is no greater than that of some other water companies, they had the supply available because their watersheds are heavily forested and well protected. A good water run-off was in evidence at all times.

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