find out personally what the conditions were, and I was perfectly thunderstruck. I might say, incidentally, that outside of my official connection with the city I am, in private life, an engineer. This thing appealed to me from the engineer's standpoint. The Colorado River, as you know, has a flood season during certain times of the year when a perfectly enormous amount of silt or dirt is carried down from these upper regions. That is the real menace of the Colorado, it is the dirt which is carried down there. That dirt, without going into too minute figures, is sufficient in quantity to cover the District of Columbia 4 feet deep every year, if spread out over the District. In order to keep this dirt from building up this point down here [indicating on map] dikes have been put up to hold back the water. You see at one time all of the Imperial Valley was a part of the sea. The dirt which was washed down here early built up a dam here [indicating] and gradually dammed off the valley, the river running along the eastern edge of this bank down into the Gulf of California. That dirt continues to come down, and is building up this delta of the Colorado. It is confined here by this levee, which ties it up in a certain channel to a certain extent, but it simply confines the area over here, over which that dirt is deposited, and it means that the bed of that river is being built up just that much more rapidly. Roughly, the area over which that dirt is being deposited is building up about a foot a year-the bed of the river is being raised a foot a year. Let me give you one definite figure. At this particular point here, down at the beginning of what is called the Pescadera cut at the mouth of what was the Bee River, when the river was first diverted, with the river running fairly full, the height of the water was 76 feet above sea level. I was down there about a year and a half later, and with less water in the river than there was the first time, the gauge read 78.4. The bed of that river had pushed the river up 2 feet during that time. That means that these mud dikes will have to be raised that much. At this point on the Volcano Lake Levee I had figures two years ago, accurate figures from the bench marks of the engineers there in charge, and the bed had raised 8 feet above what it had been when the dike was put in there. In other words, the river bed was 8 feet higher than the land was on the valley side. That shows you what is happening. Mr. SINNOTT. How are they going to handle that silt when the dam is built? Mr. BACON. There will be no silt there. That is one of the great functions of that dam, to take that out. Mr. LITTLE. Do you know that the River Nile runs in a bed higher than the valley around it? Mr. BACON. This is due to the same reason. it up. The silt is building Mr. SINNOTT. I wish you would explain that. You say that there will be no silt in it? 92265-24-PT 2-10 Mr. BACON. I will do so. In order to control the flood and hold the silt back and prevent it building up that bed, a proposition was put up to the Government. It was not a private proposition; it was nobody's idea and nobody's pet scheme. This menace existed; this constant, yearly menace that this valley would be absolutely drowned out; because this is a great saucer or bowl here, 250 feet below the level of the sea, and once the water starts to flow in there and fills it up, it would take probably 150 years for that water to evaporate and for the valley to come back into condition again. It can not be drained and it can not be pumped out. There is too much of it. In order to overcome this awful menace which the Imperial Valley faces, the problem was put up to the Government some time ago, among others, by the Imperial Valley Irrigation District, requesting a solution. They reached the conclusion that the solution of the difficulty was to build a dam at Boulder Canyon. The CHAIRMAN. When you say "they," whom do you mean? Mr. BACON. The engineers appointed by the Government reached the conclusion that the solution of the difficulty was to build a dam at Boulder Canyon. The selection of that site was arrived at after they had gone over very voluminous data. Mr. LEATHERWOOD. Is there any site below the proposed Boulder Dam where you could build a dam 600 feet high? Mr. BACON. No, sir. Mr. LEATHERWOOD. That is the farthest site down the river where you could build a dam 600 feet high? Mr. BACON. Yes; and Mr. Herbert Hoover, when he appeared before this committee, said that he knew of no site anywhere, where the natural advantages seemed to lend themselves so much to the building of a dam. Mr. RAKER. He was an engineer, was he not? Mr. BACON. Yes; and he spoke as an engineer. Back of that site, there is an immense tract of useless land which could be flooded upstream of the Boulder Dam, and this can be allowed to fill up, and you would remove your silt menace by that method, and you could control your river so that you would never have a flood; you would simply have a steady flow of 20,000 to 25,000 second-feet. Mr. LEATHERWOOD. We are not engineers and we have not seen these big dams. How would the water be taken off from this structure, 605 feet high? How do they let the water out? Do they let it flow over the top? Mr. BACON. No, sir. Mr. LEATHERWOOD. Or do they have gates in the face of the dam? Mr. BACON. Probably the method of construction would be something like this. The first step would probably be to cut a hole through one of these cliffs at the side of the canyon sufficient to carry the entire flow of the Colorado River. Mr. LEATHERWOOD. I think you misunderstood me. After the dam is fully completed, then how is the water released from the dam? Mr. BACON. Through big valves that would allow the water to flow through. Just to use a lay term-through a large pipe that would lead probably to a power house. Mr. LEATHERWOOD. Those valves will be at various intervals up the face of the dam? Mr. BACON. Yes, or they could be at one place. The probability is that they would be at different places. The idea is to get the greatest elevation of the water, the greater the fall the greater the power. It makes no difference at what particular point the outlet is. Mr. LEATHERWOOD. That is just the thing I was coming to. Would it make any difference in the handling of the deposit of silt as to where you released the flow from this dam? Mr. BACON. Oh! That would be a very simple independent prob-. lem, and easily taken care of in the construction of the dam. Mr. LEATHERWOOD. It would become more difficult from year to year? Mr. BACON. No, sir. Mr. LEATHERWOOD. You would have to go higher up every year? Mr. BACON. That would be taken care of when the dam was constructed. It is the common practice to put in a large vertical pipe 15 or 20 or 30 feet in diameter, and into that vertical pipe at points are openings so that you can bring your water from the 5-foot or the 100-foot or the 500-foot level. It is all done when the dam is being built. It is the common, ordinary dam construction. That dam will back the water up 80 miles, and the deposit of the silt would begin 80 miles above the dam. The CHAIRMAN. There is very little silt deposited below the dam? Mr. BACON. There would be no silt except what comes in from the Gila River which is comparatively small. There is an indication as you will see on the map that formerly the Colorado flowed down here carrying its silt to approximately that line here [indicating on map], that is about half way between the international boundary line and the bay. Then it commenced to deposit, as you can see by the way it branched out. Then the clear water, after it had dropped its silt, collected again into a well-defined channel and flowed on down. Silt is probably being deposited here over a band 20 or 30 miles wide [indicating on map]. The CHAIRMAN. That is in the vicinity of Bee River? Mr. BACON. It would be about at the lower end of the Pescadera Cut. Wherever the water stops flowing or slows up, the silt drops. You could take a glass of that water, as we used to do with the water in St. Louis, and let it stand over night, and the mud would be all at the bottom. But to return to this proposition here: you have heard of the foreign menace that the Imperial Valley faces by having their water absolutely under control of a foreign government. The condition is almost inconceivable, to think that a foreign government has absolutely its clutches on the throats of every man, woman, and child in the Imperial Valley. Mr. LITTLE. When this proposition came up first, here, there was not any government of Mexico, and they were greatly indebted to us down there for people they had killed, and stuff they had stolen, and I suggested that this Government should take possession of that valley down to the Gulf of California, and keep it until they settled with us. I still think that I was right. Have you any judgment about that? Mr. BACON. I think I would agree with you absolutely. Colonel. Mr. LITTLE. It would have been a practical and sensible thing to have done right then, would it not? Mr. BACON. I am not familiar Mr. LITTLE. There was not any government in Mexico. There was not anybody there that could have taken it up, if we had just taken possession and said, "We will return it when you settle up with us," and it would have given us a life title to it. It was a very sensible and practical thing to have done, in my judgment. Mr. BACON. It certainly would have solved some of these problems that are coming up to-day. To protect the Imperial Valley's water supply it is necessary to have this all-American Canal, and that is the thing that San Diego is interested in probably from a personal standpoint as much as anything else. Now, let me take your time just briefly to outline the water situation as it exists in California to-day. At the southern end of California we have no live streams. Our water must be stored in the upper reaches of what mountain streams there are. Our records show in San Diego that not very long ago there was a period of seven dry years, during which there was practically no rainfall and almost absolutely no run-off. In other words, for a period of seven years things were dry. Now, taking advantage of that information, we plan in our city to maintain or provide storage for a 7-years' supply of water. That we must do in order to be safe. Mr. LEATHERWOOD. Do you mean that you have a sort of a cycle there of dry years and wet years? Mr. BACON. Yes, sir; we have a cycle of dry years. has been a period of seven dry years. We know there Mr. LEATHERWOOD. Did you get that data from the Weather Bureau? Mr. BACON. No, sir; we had that from the United States Geological Survey and also from the records that are kept yearly. Mr. LEATHERWOOD. Bearing out that contention, in fact, I would say there is very accurate data to show that that condition exists in the Great Salt Lake Valley. It runs in cycles of about 10 years there. Mr. LITTLE. How do you keep that out of the knowledge of the people that go in there? Mr. BACON. They know it. We tell them. We have to-day about 5-years' supply of water ahead. This has been a dry year. We have various engineering reports made by the city, and we are waiting now for a report from Mr. John R. Freeman, of Providence and New York. I think his name is familiar to you. We engaged him to come out there and make a report for further improvement and development. That report is going to cost the city $30,000; that is just for the report. Without even waiting for that report, in order to have money on hand to go ahead when that report is received, I received a telegram the other day that the city council have authorized an election to pass on a bond issue of $3,500,000, so as to be ready to jump right in and get immediate results when that report comes. Mr. LEATHERWOOD. Where do you get your water supply? Mr. BACON. From the mountains back of San Diego. We have to-day about 40,000,000,000 gallons in storage. Mr. SWING. How far do you have to take that storage? Mr. BACON. About 40 miles. Mr. LEATHERWOOD. That would not seem to indicate that San Diego is kind of dead, as they say it is down in Los Angeles. It seems to me you are pretty much alive down there. Mr. BACON. Let me quote from the United States census returns. San Diego's increase or growth between the years 1900 and 1910 was 126.6 per cent. Between the years 1910 and 1920 it was 88.7 per cent. The growth of Los Angeles between those last two dates was 80.7 per cent. Mr. SWING. You are giving it for 1920? Mr. BACON. That was the last census. However, we have an estimate looking ahead. The CHAIRMAN. Does the population seem to be increasing in the same proportion? Mr. BACON. It seems to be, from the water meters. We have the water fully metered, and we can get a pretty good idea of the increase in the population from the applications we have for water meters. The United States census for use in connection with vital statistics gave us as of January 1 a population of 97,000 people. As nearly as we can tell, that does not include figures as to the transient population, of which we have a very great proportion. For the purposes of our own water department we estimate the population at about 120,000, which I think is a fair figure. Mr. SWING." What was it from the census of 1920? Mr. BACON. The last figures I saw, they send to the health department each month Mr. SWING (interposing). No; but what was it in 1920? Mr. SWING. And now the Government gives you 98,000? Mr. BACON. Ninety-seven thousand and a fraction. It is about 98.000. Mr. SIMMONS. Would it be in order for me to suggest that while the population of San Diego was given at 98,000, the population of Scotts Bluff, Nebr., increased 298 per cent? [Laughter.] Mr. LITTLE. Everybody has to be sworn here. from Mr. BACON. Here is the point I wanted to bring out in connection with our water supply: Some years ago Virgilio Bruschi, a member of the common council, who was not an engineer but who knew that country thoroughly, suggested we might get some water from the Colorado River. His idea was rather looked upon then in a questioning way until recently. No attempt was made to get away the general idea until Mr. John F. Covert, an engineer of one of the water companies that supplies the water to lands below San Diego there, the lands north of San Diego, carefully went over some maps and we made some estimates, and we discovered that it would be perfectly practicable and well within the bounds of possibility to take water from the end of an all-American canal, and with cheap power from Boulder to pump it up to an elevation of 2.500 feet, run it through a tunnel, and drop it down on the other side of the mountain, recovering a large percentage of the power, and then use the water in San Diego. The pumping would be absolutely prohibited without cheap power, and it would be also prohibited if it was |