landowners have along the Mississippi. The need is urgent in Palo Verde Valley and in the judgment of the advisers, the Government should assume control of the Palo Verde levees along the Colorado as a part of the general treatment of Colorado River in connection with Boulder Canyon Reservoir.

(2) In view of the impossible burden which the Palo Verde farmers have assumed in the past, the valley should be reimbursed out of the General Treasury for such past flood-control work as is found to be of value in the general handling of the river. The advisers are not informed, however, as to the extent of such reimbursement which is justified.

A study of this report prompted Congress to pass the act approved April 19, 1930, directing an official survey to be made of the physical and economic problem of the Palo Verde Valley.

The act is as follows:

Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the Secretary of the Interior is hereby authorized to make all necessary engineering and economic investigations and studies of conditions in the Palo Verde and Cibola Valleys and vicinity on the Colorado River in California and Arizona to determine how best to protect the lands in this vicinity from damage by overflow and seepage. Report shall be made and plans and estimates prepared showing cost of additional works necessary, together with a statement of the value of works already constructed which can be merged with and made a part of a completed system.

The investigations asked for were made by the engineers of the United States Reclamation Service during the summer and fall of 1930 and at the opening of Congress a full report covering an exhaustive survey of the valley's condition was filed by the Secretary of the Interior. This official report again strongly recommended that Federal assistance be given this community, declaring that long sections of the existing levee "should be raised 3 feet for safety from being topped by the high floods." The report further showed the complete inability of the settlers to save themselves, saying:

At the present time in order to carry on the operations of the district a trust fund in the hands of three prominent citizens as trustees is being supplied from the payment of district assessments by the water users and used to defray operating expenses. This arrangement was worked out to evade the payment of charges to the county treasurer, for had this been done, they would have been applied immediately to delinquent accounts and no funds would then have been available for the district's operating expenses.

The condition of the project is such that unless means for relief are worked out in the immediate future the Palo Verde Irrigation District will cease to function.

Thereafter a bill (H. R. 13575) was introduced in the Seventy-first Congress to carry out the recommendations of the two reports of the experts who had studied the problem. On this bill the Secretary made a favorable report conditioned on the adoption of several amendments to safeguard the public interest and guarantee that the pioneer settlers would get the primary benefit of the Government's assistance. The most important of these is that the holders of the outstanding bonded indebtedness shall agree with the Palo Verde irrigation district to reduce that indebtedness to an amount which the Secretary of the Interior shall find and determine is not in excess of the district's ability to pay. Another is that the Government's assistance shall be spread over five years in annual installments of $200,000. Another is that the land that has already been sold for taxes and which hereafter may be sold for taxes shall be offered first for repurchase to the last owners, who shall have a preference right for one year in which to purchase their former holdings at their fair appraised

value not exceeding the accumulated taxes and tax penalties against the land-this to prevent speculation. A further provision of substantial value to the Government is a release of all claims, past and future, for damages that have or may hereafter result from flood, and a further agreement that the Government may be free to construct such dams and diversion weirs in the river below the Palo Verde Valley as may be found necessary or desirable in the future development of the river and for the utilization of its waters within the United States. This waiver and release is of importance because there exists grave doubt that the Government is responsible for the flood which inundated this valley in 1922 through its construction of the Laguna Dam near Yuma, Ariz. Colonel (now Brigadier General) Deakyne and Major Ardery, Army engineers who surveyed the flood, estimated that it did damage to property in the valley to the amount of $1,000,000.

True, the Government engineers discount this claim but every engineer that the Palo Verde district has had in charge of its works has declared that the construction by the Government of the Laguna Dam was a direct and contributing cause to their break and flood in 1922 and their present flood menace. Respectable engineering authority and data was presented to the committee to support this contention. Official records kept by the district show that shortly after the construction of the Laguna Dam the bed of the river in front of the Palo Verde Valley started to climb and has increased in elevation between 6 and 7 feet, that no corresponding increase has been found in the bed of the river below the dam, but on the contrary the change such as it is shows some reduction.

Paul Frisi, prominent Italian engineer, in a work first published in 1762, based on observations and experiences with the Po, the Arno, and other rivers declared:

It is very certain that in places where the courses of rivers are impeded by rocks or similar obstructions, or are crossed by some sluice, dam, or cataract, the whole bottom of the river is more elevated, because, as is well observed by Guglielmini (ch. 12), the dam, or sluice, as soon as erected, by refusing a free passage to the water and retarding its stream, facilitates the deposition of stones and gravels; and the bed of the river at the sluice being thus raised to the height of the sluice, causes a proportional heightening in the upper part of the same bed.

Guglielmini had already observed that dams and sluices retain only a portion of the stones that are brought down from the mountains-that is, so much only as is requisite to fill up the void formed by the height of the sluice, which once filled, the river begins afresh to establish its bottom, above the sluice, on the same slope which it had before. Father Grandi, in his Considerations on the Dam, thought he could infer from some principles laid down by Guglielmini that the bottom of the river must establish itself on a curve similar to that which it formerly had, which, beginning at the top of the dam, would extend throughout the whole of the upper space until it met some other dam, or a collection of rocks, or some other obstacle, either natural or artificial, by which the continuity of the bed was interrupted. (Frisi, Rivers and Torrents, pp. 25, 30, 31.)

This phenomena has also been observed and noted by American engineers on American rivers.

The report of the Mississippi River Commission for 1912 found in Senate Document No. 366, Sixty-third Congress, declares:

Any sedimentary stream, having a definite succession of stages and discharges and flowing in its alluvion, finally takes such a slope as will give a velocity sufficient to enable it to carry its sediment, whether derived from above or from its own banks and bed, farther dow...ream, without, on the whole, scouring or filling its bed. When, therefore, the slope of a sedimentary stream suddenly diminishes from that which it needs for a stable regimen its velocity also diminishes, it drops part of its alluvion, and its bed rises.

The Mississippi pushes its mouth out into the Gulf at the rate of about 4 miles in a century, and this increase in length requires a corresponding increase in fall of water surface to make the rate flow out. An increase of 4 miles in length would, with existing slopes, raise the high-water surface at New Orleans (90 miles upstream) about seven-tenths of a foot.

Mr. H. T. Cory, prominent engineer of the West and sometimes adviser to the Interior Department on reclamation projects and a man who had much to do with the Colorado River, in his exhaustive discussions of that river before the American Society of Civil Engineers in 1913 (see Transactions of the American Society of Civil Engineers, December, 1913, pp. 1213, 1214), says:

Assuming a given discharge, and conditions of equilibrium, the bed of the river will have a given slope, the water will have a certain velocity, and will carry a certain quantity of sediment, none of which will exceed a definite size or specific gravity. * * * When the velocity slackens, resulting in carrying less silt, the bottom will rise with increasing slope until equilibrium is again established. * * * As the river builds the delta farther and farther into the Gulf of California, the bed must rise all along the line, of course, taking averages of considerable periods of time.

The prolongation of the beds of the Mississippi and the Colorado by the projection of their respective deltas has, in a way, the same effect on the raising of the bed of the river that the construction of a low dam would have on the channel above it.

These are sufficient quotations to show that recognized engineering authorities support the contention that silt-bearing streams, flowing in channels which do not contain obstructions, either natural or artificial, will seek to establish, throughout that entire section of the stream, a normal grade which will give the water a velocity sufficient to carry its silt burden without scouring the bed. This may be called the natural slope of the bed. When this slope or grade is interfered with the stream at once starts to readjust its bed, upward or downward, as the case may be, seeking once more to reestablish a natural or normal grade, and, given sufficient time, the readjustment of the bed will be effected from the point where the interference took place back up the full length of the stream to the next insurmountable barrier in its bed.

This is what seems to have happened on the Colorado River. The Government constructed the Laguna Dam, 17 miles above Yuma, with an elevation of 12 feet above normal low-water surface. The first year resulted in the basin back of this dam being completely filled with silt. But the river did not stop with merely running a horizontal line from the top of the Laguna Dam back until it struck the former normal slope of its bed, but it continued thereafter to raise its bed farther and farther back-bringing it nearer and nearer to a uniform and continuous slope or gradient from the top of the Laguna Dam upstream past the front of the Palo Verde Valley for a distance of more than 100 miles.

There seems to be no question but that this raise in the bed of the river, following the construction of Laguna Dam, contributed directly to the break in 1922 and the resulting losses of $1,000,000, and also that most of the expenditures on river-front protective works after 1909 were necessitated by the same cause, which expenditures total $2,400,000.

But, aside from the liabilities for past damages, the Government has now assumed the flood-control problem on the lower Colorado

River. It has made substantial contributions to the other communities on this river in connection with their expenditures for protective works. Palo Verde Valley is the only community of any size on the lower Colorado that has been left to fight its own flood battles alone. The committee feels that the Government should accord Palo Verde Valley the same treatment it has given to Yuma Valley and Imperial Valley. This bill leaves the Government's contribution less than half that actually expended by the settlers in the construction of levees and protective works.

This contribution will save to the country the life of an important community, created by the courage and hardihood of pioneer settlers. The committee feels that, under all the circumstances, the Government owes an obligation to assist Palo Verde Valley-an obligation that it ought to have performed heretofore-and one that it most certainly should render now, unless it is willing to see 3,000 people lose their homes and life savings and a thriving community turned back to the desert.

The favorable report of the Interior Department on H. R. 13575 of the Seventy-first Congress is as follows:

Hon. ADDISON T. SMITH,

DEPARTMENT OF THE INTERIOR,
Washington, February 14, 1931.

Chairman Committee on Irrigation and Reclamation,

House of Representatives.

MY DEAR MR. CHAIRMAN: In compliance with your request of December 3 for a report on H. R. 13575, which is a bill that would provide for the protection of the Palo Verde Valley, Calif., against injury or destruction by reason of Colorado River floods, I transmit herewith a memorandum on the subject that has been submitted by Commissioner Mead of the Bureau of Reclamation. After a review of the proposed measure, I agree with Doctor Mead. Very truly yours,

RAY LYMAN WILBUR, Secretary.

DEPARTMENT OF THE INTERIOR,
Washington, February 14, 1931.

Receipt is acknowledged of the letter of December 3 from Hon. Addison T. Smith, chairman Committee on Irrigation and Reclamation, House of Representatives, requesting an expression of opinion regarding the merits of H. R. 13575, "a bill for the protection of the Palo Verde Valley, State of California, against injury or destruction by reason of Colorado River floods."

I am advised that the Palo Verde irrigation district of Riverside County, Calif., has need of assistance in making repairs and betterments to its levee system for the protection of about 79,000 acres of irrigable land from the floods of the Colorado River; in the past 20 years the district has expended about $2,400,000 in flood-protection works and has exhausted its available cash and credit for continuing such work; and that unless means can be found to put the levee system in good condition the entire community may have to be abandoned and heavy losses will be then sustained by property and district bond owners.

The Palo Verde Valley, in 1921, had a population of upward of 5,000 people and 40,000 acres in productive cultivation. A disastrous inundation of the valley in 1922, following a number of preceding breaks, did the farmers great actual damage and impaired the community's credit on account of possibility of recurrence of loss. The further expenditures necessary to restore the river to its channel and build up levees and the failure of many farmers to return to their lands and homes resulted in an increased tax burden falling upon the remaining settlers, with the result that the tax burden to-day has reached a figure, I am advised, of approximately $20 per acre, which is more than the agriculture of this valley can afford.

It has been contended by some that the building of the Laguna Dam, 60 miles below the south end of the Palo Verde Valley, has intensified the flood problem of that community. The Government engineers do not agree with this theory.

There are other engineers who contend that the building of a rigid bar across the river in the form of the Laguna Dam, raising the water 12 or 14 feet above the low flow of the stream, has, by checking up the river to that extent, decreased the gradient of the channel between Palo Verde and Laguna Dam, thereby slowing up the flow of the river and resulting in the dropping of an increased amount of the heavy silt burden carried by the river, thus raising its bed in front of the Palo Verde Valley.

But whether any influence can be directly attributed to the Laguna Dam or not, it is the intention of the Government in carrying out the Boulder Canyon project either to substantially increase the height of the Laguna Dam or to build a new diversion dam closer to Palo Verde in order to get a higher take-out for the All-American Canal, which is to be built for the benefit of the Imperial and Coachella Valleys. This new activity may possibly throw a burden upon the Palo Verde Valley, although the possibility is speculative, and is not credited by our engineers. If so, this might furnish additional reason for the Government's coming to its assistance. However, if such assistance is so given, the Government should be relieved of all claims or liability, if any, on this score. To cover this, a release from the district and the property owners is provided for in substitute bill hereinafter suggested.

When the Boulder Canyon project was authorized by Congress it thereby declared a policy of Federal control of the flood problems of the Colorado, which is an interstate, international navigable river. When the dam is completed and in operation it is believed that not only will the storing of large quantities of water reduce the height of all floods but the realease of clear water from the reservoir will result in the picking up of the silt which now chokes the channel of the river in its lower regions and result in a gradual deepening of its bed with increased security to all communities on the lower stream. These beneficial results, however, can not be anticipated in a substantial degree for several years after the dam is completed.

The critical period for the Palo Verde community is therefore between now and the time when the Boulder Canyon project is put into operation. Immediate work for the strengthening and raising of the river flood protective levees is necessary. The area will also require relief from the heavy tax burden, which was incurred in large part in fighting the river and which is to-day greater than can be borne by the community. The Federal Government donated $1,100,000 for the construction of levees for the protection of the Imperial Valley, which is the next community below Palo Verde on the California side. The Government has also aided the Yuma Valley, the next community below Palo Verde on the Arizona side, with contributions to the extent of more than $735,000 for its flood protection. The Federal Government has so far made no expenditures to aid the Palo Verde Valley. If a corresponding assistance had been given to the Palo Verde at the time when it was needed the valley might not now be in its present condition.

Adequate water rights, fertility of soil of the 79,000 acres which are embraced within the district, the long growing season, close proximity of large markets are factors which, under normal conditions, would afford security for a reasonable bonded indebtedness against lands of this valley. However, under conditions that exist to-day, with the continued threat of flood, with the rapidly decreasing number of taxpayers, with the valley's finances exhausted by its long fight against the river, the probable course of events will be the driving out of most of the present owners and the acquisition of the entire lands and water rights by the bondholders or some organization representing them. To permit this valley to revert to waste areas with the resultant loss of the life earnings of the settlers would be an economic waste which should be prevented, if it can be prevented within sound economic principles and past governmental practices. The bondholders, on the one hand, and the Government, on the other, may cooperate to save this community. To do so the outstanding bonded indebtedness must at least be cut in half and a reduction of the tax must be made to an amount which the present landowners can pay.

It should be understood that any sums paid over to the district by the United States under this act will be used for the retirement of bonds on such a cooperative basis.

Representatives of the bondholders, landowners, and district officials have expressed a willingness to abide by the results of any economic survey the Gov. ernment may make to determine just what the settlers can afford to pay. Therefore, any relief undertaken by the Government should be made contingent upon at least equal contributions from the creditors of the district. It is accordingly