would directly and adversely affect the efficient conduct of many Federal activities.

WORK OF THE GEOLOGICAL SURVEY

The work of the Geological Survey touches the problems of river development and utilization at several points:

1. The systematic collection of records of discharge. This work which has been in progress for 40 years, is carried on in practically every State, the cost being shared to a large extent by cooperating State and municipal agencies. The records are used constantly by engineers, financiers, attorneys, and courts in connection with the design, construction, and operation of works utilizing water, in the liquidation of damages caused by water and adjudication of rights in water. The records are also used extensively in connection with problems of administration by Federal and State agencies.

2. The study of ground water, its quantity, recovery, and utility. This work is also carried on largely in cooperation with States and municipalities. It involves the obscure and difficult problems related to recharge and safe yield which are coming into consideration_in many localities because of the lowering of ground-water stages due frequently to excessive withdrawals. Ground-water supplies are always intimately related to the normal and low-water flow of rivers and there is now a trend among engineers and geologists toward a joint study of these two aspects of water resources. Stages of ground water are being more and more studied by engineers in connection with their estimates of the probable low-water flow of rivers.

3. The Survey studies the chemical quality of water with especial reference to its utility in agriculture and industry and for this purpose maintains a chemical laboratory in Washington where several chemical analysts are employed. This work is done with respect to both surface and ground waters. The results form the basis for the selection of sites for industries, for the classification of municipal water supplies with reference to chemical quality, and for the planning of many commercial activities in which the chemical quality of water is highly important.

4. The Survey compiles and publishes monthly and annual records of the production of electricity for public use and of the consumption of fuel used in such generation. In connection with such records there is published also an annual report of the total capacity of water wheels in hydroelectric plants of 100 horsepower or more.

5. The classification of public lands with respect to their alienation or utilization under the public-land laws. This classification includes a consideration of the water supply in its relation to irrigation and to the development of water power.

6. In connection with the classification of public land the Survey studies soils, vegetal cover, erosion, and related subjects.

7. The Survey prepares reports on the best methods of utilizing water resources for all purposes and in connection with certain of the problems presented it undertakes to set up comprehensive plans for the development and utilization of rivers and to estimate relative values of water for varied purposes and in different regions.

8. The Survey studies the geology of particular sites as well as of broad areas. It reports on the soundness and integrity of dams and reservoir sites.

9. The Survey prepares, largely in cooperation with States, the well-known standard topographic map which is used basically for many purposes and in many different ways.

POLLUTION AND SEWAGE TREATMENT

(Statement submitted by Mr. N. C. Grover, Geological Survey)

Rivers are the natural drains of the basins through which they flow. They are provided by nature for removing surplus water and whatever may be carried therein. By no human device can this function of rivers be changed.

Into rivers must be discharged the sewage of cities, the effluents of industrial plants, and other water that has been polluted by man. In many regions there are no other practicable means for removing these wastes. Thus rivers have and will continue to become polluted as a result of man's activities. Within reasonable limits such pollution is unavoidable. Rivers are, however, a common heritage of man, used for many purposes and must be kept in such condition of relative purity that reasonable use for many purposes may be possible and that they may be sources of enjoyment to everyone who uses them or lives on or near their banks. They should not be permitted to become so polluted that they are offensive or that they are unreasonably damaged for proper utilization.

It is, therefore, proper that cities should be required to treat sewage before discharging it into rivers so that damaging or offensive conditions below the points of outlets of sewers will be prevented. Similarly, industrial plants which discharge large quantities of effluents should be required to remove those chemicals or offensive wastes that would endanger the health of those living near the rivers, thereby making possible the reasonable utilization and enjoyment of their

waters.

Much is said and written about conservation of our natural resources. There is probably no more important aspect of conservation than the reasonable protection of the quality of this greatest of natural resources for the welfare of present and future generations.

WATER IN RELATION TO DRAINAGE AND EROSION OF AGRICULTURAL AREAS

(Submitted by the Bureau of Agricultural Engineering, Department of Agriculture)

In planning a control of water program, the following phases of the work carried on in the Bureau of Agricultural Engineering are recommended for consideration by representatives of the Department of Agriculture for the various regions.

The Bureau is primarily interested in three principal types of work which may be present on all proposed projects; that is, erosion control, drainage, and irrigation.

In controlling sheet erosion any or all of the following methods may be used:

First, protect cultivated fields by terracing, generally limited to land with slopes of 12 percent or less. Second, the taking out of cultivation of some of the steeper slopes and seeding them to grasses for hay or pasture. In some regions pastures can be materially improved by

the construction of terraces to conserve moisture. Third, the planting of trees or other vegetation on areas too steep or too badly eroded for cultivation or pasture.

In the Great Plains region in comparatively level areas of 1 to 2 percent slope, terracing to conserve moisture for crop use should be recommended. In controlling gully erosion, the construction of check- and soil-saving dams should be considered in any program of planting.

The drainage of wet spots in cultivated fields should be recommended. All sloughs or wet uncultivated areas for the conservation of wild life should be carefully considered before drainage is recommended. Under a flood-control program, the drainage of agricultural lands protected against floods should be considered. For complete development under a long-time program, flood protection for the benefit of agricultural lands should be included but such protection is not generally to be recommended at the present time.

In the arid regions preferential right in the development of the water should be for domestic purposes, then for agricultural purposes, and finally for hydropower where the uses are irreconcilable. The immediate purpose in planning should be the supplying of additional water for areas already under cultivation where the present supply is deficient in the late season rather than bringing in new lands. In the arid region also we believe in an organized control of the watershed which would include range management, lumbering, and erosion control, all with the idea of getting the greatest good out of the main natural resource, which is water. In many sections of the West which are or will be irrigated, artificial drainage is necessary and should be given consideration in any development plan. The conservation of water for agricultural and industrial purposes will frequently take care of the flood-control problem on many of the western streams. The irrigation farmer is especially interested in a regulated stream flow which means the storage of flood waters and their release during the summer months.

In a general long-time program for the development of agriculture in various areas, the Bureau is particularly interested in securing a more general and more efficient use of electricity in agriculture, and for individual farms it is particularly desirous to secure a better balance between crops, livestock, farm machinery, farm buildings, and field conditions. The general purpose of the work of the Bureau is to secure a greater degree of efficiency in crop production and a betterment in the living conditions on farms.

WATER IN RELATION TO WILDLIFE

(Submitted by the Biological Survey)

Water not only is necessary to wildlife in general in catering to almost universal physiological needs as exemplified by its use for drinking and bathing but is the actual home of fishes and a multitude of other organisms. Most of the wild fowl, including our highly valuable ducks, geese, and swans, and such fur-bearers as muskrats and beavers, are absolutely dependent on water for their reproductive activities and, in fact, during most of their life. The groups of shore birds, coots, rails, gallinules, and herons are almost as closely associated with water and a multitude of species generally grouped under

the term of fish-eating birds depend upon creatures inhabiting water for their subsistence.

Among the desirable conditions with regard to the water supply are continuous availability, stability of levels, and purity. Conversely undesirable conditions are fluctuations in level, or more important still in the very presence of water, and pollution in the form of industrial wastes, sewage, or oil. It is well known that each of these types of pollution has been responsible for great destruction of wildlife.

To assure a dependable supply of water for some forms of wildlife, it is necessary to set aside marsh and lake areas for the primary use of wildlife. This has been done to a certain extent by the establishment of Federal and other reservations but the movement needs to be greatly expanded in order to benefit wildlife in all parts of the country. The Biological Survey has been carrying on a program of refuge acquisition for many years, but funds have never been sufficient to permit establishment of the necessary system of marsh and lake areas to guarantee a fair chance of existence to the migratory waterfowl. The establishment of refuges for nonmigratory species dependent on water is more a function of the States, but it can confidently be said that provision of an adequate number of refuges of this character also has only begun.

To sum up, the preservation of many forms of wildlife of our country is possible only if supplies of good water are constantly available, water levels are preserved, and pollution prevented.

WATER AND SOIL EROSION

(Submitted by the Soil Erosion Service)

THE PROBLEM

Relation of accelerated erosion to beneficial use of waters.-Immigrants to the American Continent found a region so rich in resources of land, timber, game, fish, fur, navigable streams, etc., that there early developed the false concept of limitless and inexhaustible supplies. This concept has persisted until today. Naturally there seemed no limitations to the promise of rich rewards held out to the eager explorers and colonists three centuries ago.

Except in an insignificant way, the aborigines had done little to cultivate the soil or to change the virgin character of the land surface and its vegetation. The coverage of vegetation and the soils protected by it were natural responses to the long processes of soil and plant development under favorable climates. The streams. bore oceanward the residue of precipitation waters that flowed gently from sloping areas and nourished vast unbroken stands of vegetation. Rivers draining the regions covered with dense vegetation ran clear except in high flood when channel erosion furnished the major burden of silt. This channel erosion generated soil creep from vegetated slopes and in addition to solution served to sculpture and wear down the land with the leisure of geologic processes. When comparatively rapid differential land uplift had occurred, or within climatic zones too rigorous or too arid to support an unbroken cover of vegetation, storm waters carried substantial quantities of silt into the drainage of streams. Processes proceeded in these cases at more

rapid rates; streams ran muddy throughout most of the year, as in the instances of the Missouri and Colorado.

In the broad expanses of the country, from semitropical to boreal climates, from humid to arid conditions, there spread before the eager colonists an infinite variety of conditions. By far the larger area was completely covered with vegetation ranging from grasses to dense forests. Such coverage had in the long period of interdependence of soil formation and vegetative succession protected the land surface from rainwash, and favored the absorption of rain and melting snow by deep soils honey-combed by the burrowing of insects and plant roots and made porous by natural processes of soil development. Little surface washing occurred. Certainly the processes of erosion, which may be designated under these circumstances as a geologic form of erosion, had not proceeded at rates in excess of those of soil formation. For beneath the cover of vegetation lay the nourishing soils of varying depths, the product of intricate processes of soil formation during thousands of years. This fact is of highest importance in considering problems affecting long-time planning in land use. Erosion had not exceeded soil formation under these native conditions. Into this pristine continent entered the colonists with a burst of energy that began a transformation of the earth's surface at a rate probably never before occurring in the earth's history, and with it the creation of a nation of fabulous wealth. There were reservoirs of population in Europe which supplied in a comparatively short time millions of vigorous people to clear away the forests and to cultivate the soil at an astonishing rate in their westward march of agricultural occupation. It was no steady infiltration into undeveloped regions but a rapid advance over a wide front by farmers and stockmen with their plows and herds. Frontiers were pushed farther and farther westward at a pace that eliminated planning or thought of the effect of man's activities upon the abundant natural resources that everywhere swept away to the horizon. Man was busy "subduing the wilderness", slaughtering the buffalo for their hides and breaking out first the sod of the prairies and then the short grass of the plains on the west. There was no immediate necessity for thinking of conservation in any form or degree.

Withal, it is only necessary here to call attention to the significant changes in rate of erosional processes occasioned by the clearing of vegetation, the breaking of the soil with plows and the heavy consumption of the forage herbage by rapidly multiplying herds. Soils, which had been thoroughly protected through thousands of years of time by unbroken mantles of vegetation and had for this reason been weathered to fine textures, high organic contents, and good fertility, were suddenly exposed to the dash of torrential rains over extensive areas. There began under these conditions a rate of erosion which was accelerated far above the rates that hither to obtained. The significant fact of this period is that the rate of soil removal by rain water greatly exceeded and still does exceed the rate of soil formation over vast areas- a sure process of soil destruction. Topsoils have been literally washed away, leaving raw subsoil exposed at the surface, such as is conspicuous over the entire Piedmont region of more than 50,000,000 acres, as well as over numerous other regions throughout the country. Moreover, concentration of run-off has cut enormous gullies through the topsoil and subsoil into the