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Therefore, my experiences which have made it possible for me to become acquainted with the many problems of the Boise River, began in the spring of 1916, and I have been engaged in this same work continuously since that time with the exception of 1918. Naturally, therefore, I am very much interested in and feel very keenly about the problems involved in dealing with the Boise River.

During my experiences on this river there have been 8 years when there was sufficient high water or floods to cause a great deal of damage to adjacent property. These years were 1917, 1921, 1922, 1928, 1936, 1938, and 1943.

Numerous factors during recent years have combined to focus attention upon the urgent need for a permanent flood-control program to be undertaken as an immediate postwar project. These factors include:

(a) The unusually heavy precipitation over the Boise River watershed during the winter months of 1942-43 and the resultant extremely high water in the spring of 1943.

(b) The fact that a catastrophic flood was averted in 1943 only by a sudden drop of 141⁄2 degrees in temperature just as the flood reached its peak stage of 25,040 second-feet, and at the same time just when Arrowrock Reservoir was filled. The fact should be mentioned that in this country serious floods are more often caused by melting snow than by rains, although occasionally they are caused by a combination of both.

(c) The surprisingly heavy damages to adjacent property at that time, including many fine, fertile, extensively cultivated and well leveled heavy producing farms, irrigation headings and drainage works; also, local roads, market roads, county roads, highways, culverts and bridges.

(d) The fact that it was necessary in 1943 for many farm families to move from their homes, taking with them all of their furniture, poultry, livestock, farm machinery and equipment. It was a heart-rending scene to witness these many fine American families moving from their homes with all their earthly belongings in every kind of vehicle imaginable, including teams and wagons, hayracks, trucks, trailers and automobiles, when it could and should have been provented by an adequate flood-control program which would solve this problem.

(e) The terrible condition of the Boise River Channel after the 1943 flood. (Prior to the 1943 flood, the channel of the Boise River would carry between 12,000 and 15,000 second-feet satisfactorily, but after the 1943 flood, in many places it would not carry more than 6.500 second-feet, and in some places less than that, without damaging adjacent property.)

All of these factors combined have brought most forcibly to the attention of everyone concerned the seriousness of the Boise River flood situation. We all realize, and I wish to emphasize now, the need for continued channel improvements along the full length of the river throughout Boise Valley however, the condition of the channel of the river, after the 1943 run-off particularly, emphasizes the fact that channel improvement alone will not solve the flood problems of the Boise River. The slope of the valley is too great (about 12 feet to the mile), and consequently the velocity is too high. Under these conditions, the channel with the banks consisting of sand and gravel, will not hold when the flow reaches 6,500 second-feet or more. Therefore, in my opinion, a program which will solve the flood problems of this river must include not only channel improvements but additional storage space to regulate the flow and control the floods.

DRAINAGE AREA

The total drainage area of the entire Boise River watershed, including all of the area tributary to the river down to its mouth, is approximately 2,621,000 acres. The ownership and control of this area is divided as follows:

United States forest lands__.

Acres

Public domain and other Federal lands_

State-owned lands.

Privately and county owned lands___

Total___

1, 383, 870

251, 940

164, 740

820, 450

2,621,000

The area of the Boise River watershed above the United States diversion dam is approximately 2,800 square miles, or 1,792,000 acres. About 55 percent of this area, or 997,440 acres, is timberland.

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The drainage area of some of the important tributaries are as follows:

Middle and North Fork (above Twin Springs)
South Fork above Lennox.
Mores Creek_-_

Square miles

830 1, 090 426

All of the principal tributaries converge within a very short distance, not ex-ceeding 25 miles, thus intensifying a flood hazard. The proposed Lucky Peak Dam and Reservoir now under consideration will be situated below the point where these tributaries converge, thus making it possible to store the floodwaters from all of them.

RUN-OFF

Following is a tabulation showing the annual run-off in acre-feet, maximum discharge in second-feet and date of maximum discharge.

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Precipitation records for the city of Boise, when considered along with statements made by early settlers along the Boise River, all indicate that on several occasions during the early years of settlement along the river, the flow of the river was much greater than at any time during recent years of record. 1862 (flooded entire valley from bluff to 1907 (17,000 second-feet).

bluff below city of Boise).

1917 (17,848 second-feet).

1871 (highest year since settlement of 1921 (19,682 second-feet).

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From the foregoing, it is evident that there was at least 1 year in every decade prior to 1900 in which the peak flow was greater than that of any year of record, and during the decade from 1890 to 1900 there were 3 years in which the peak flow was greater than it was in 1943.

FLOOD DAMAGES

Flood damages along the Boise River, in general, can be divided into three classifications:

1. The damages resulting from inundation of small areas immediately adjacent to the river by spring floods of volume that occur about 2 years out of every 3. 2. The damages resulting from floods of approximately 20,000 second-feet which occur about once in every 5 years.

3. The damages resulting from catastrophic floods, which in the Boise Valley are floods of approximately 25,000 second-feet or more, and which occur on the average of about once in every 20 years.

With reference to the first classincation, there are a number of small tracts of good, fertile, agricultural lands close to the river which are being constantly menaced with floods.

The

As to the second classification, it is difficult and almost impossible to maintain the channel of the river with a flow of 20,000 second-feet. Floods of this proportion do considerable damage the full length of the river, not only by cutting away the banks in numerous places and destroying valuable farm lands, but also by overflowing and flooding many acres of agricultural lands. It will be noted from the table on page 5 of this statement that such floods have occurred 11 times during the last 49 years of record or about once in every 5 years. Army engineers have estimated that a flow of 7,500 second-feet, similar to that which occurred in 1935, would cause damages to the Boise Valley of approximately $80,000, and that such a flow can be expected about 4 years out of every 5; that a flow of 16,100 second-feet, such as occurred in 1936, will cause damage of approximately $456,000 and will occur about once every 4 years; that a flow of 20,000 second-feet, which is considerably less than the flood of 1943, will cause damages of approximately $1,000,000 and that it will occur about 1 year out of every 7; that a flow of 35,500 second-feet, similar to 1836, would cause damages slightly under $5,000,000 and will occur about once every 25 years; and that the maximum controllable flood of 55,000 second-feet will cause damages of approximately $10,000,000 and will occur about 1 year out of every 50.

The flood of 1943 demonstrated very clearly just what tremendous damages would result from a flow of 35,000 second-feet in the Boise River under present conditions. Such a flood would be a major catastrophe and would cause damages of many millions of dollars in the valley. Floods such as outlined above have been and will continue to be actual occurrences and will cause damages accordingly.

DAMAGES CAUSED BY THE 1943 FLOOD

Although the peak flow of the flood in 1943 passing Boise was a little under 21,000 second-feet, the damage caused was far greater than was expected or greater than anyone realized until several months after the floodwater had receded. Many acres of farm land were flooded and only a partial crop was raised, or on many farms no crops at all. In many places the topsoil was washed away and the fields were so badly eroded that it was necessary to relevel them. Transportation facilities were all seriously disrupted. In several places the floodwaters not only overflowed and cut through the local county roads, market roads, and highways, but also washed out many small culverts and bridges, all of which were not completely repaired for several months. All of the bridges throughout the valley west of the city of Boise with one exception, the Caldwell Bridge, were out of commission and traffic closed during the flood (10 in number). This completely disrupted all traffic the full length of the valley. This was especially a serious handicap to the dairy industry, which is the largest and one of the most important industries of the valley. The two big cooperative creameries at Caldwell and Meridian alone operate more than 75 milk trucks, and the total output of butterfat in the Boise Valley is more than 15,000,000 pounds per year. The closing of these market roads and highways was indeed a serious handicap to this industry.

RIVER CHANNEL AND LEVEES

The bed of the river is located on a river wash consisting largely of sand and gravel almost its entire length through what is generally known as the Boise Valley, extending from Barber, above the city of Boise, to the mouth of the river. During this distance it falls more than 500 feet, or about 12 feet to the mile. This results in a very high velocity, and especially when the flow exceeds 6,500 second-feet there is always a great deal of washing and cutting away of

the banks and a constant tendency for the river to change its course. In many places it flows along a ridge. The land slopes away from the river at least in one direction and quite often both to the right and to the left.

Thus there is a constant and continuous threat, for the river may cut through its banks and change its course entirely for a distance of several miles, overflowing rich agricultural lands that are populously settled.

Over a long period of years the landowners and residents along the river have constructed many levees and other revetment works in an attempt to hold the river in its channel. A very large part of these levees were washed away or seriously damaged and impaired by the 1943 flood. Since that time the Army engineers, through emergency funds made available to them, have replaced or repaired 45 places at a total cost of approximately $472,219. At this time I wish to express to the members of this committee who have had a large part in making these funds available and also to the Corps of Army Engineers the sincere appreciation of the residents and landowners along the Boise River for the excellent work and the results accomplished by these emergency repairs. This work has been most helpful. However, such channel improvement work alone cannot permanently solve the flood-control problems of the Boise River.

STORAGE

Arrowrock Reservoir, situated about 25 miles above the city of Boise, has a storage capacity of 286,000 acre-feet. It was built, designed entirely for, and charged to irrigation. Anderson Ranch Reservoir, on the South Fork of the Boise River, will have a total capacity of 500,000 acre-feet, allocated as follows:

Power__
Irrigation__.

Flood control and irrigation_

Acre-feet 75,000 212 500 212, 500

Thus it is evident that there is insufficient flood-control storage space now available in which to store the waters of the Middle Fork and North Fork, and no storage space to control the flow from More's Creek. As previously stated, the proposed Lucky Peak Reservoir is below the confluence of these tributaries.

PRODUCTION

In order that the members of the committee may have a better understanding of the value and amount of crops produced in the Boise Valley I would like to list some of the principal items produced, as follows:

Dairy products (60,000 cows).

Poultry-

Vegetable seed.

Fruit

Potatoes, onions, lettuce, peas, carrots, and other vegetables.

Sugar beets___

Hay and grain

Livestock

$15, 000, 000 2,500, 000 4, 000, 000 2,500,000

7, 000, 000

4, 000, 000

1, 000, 000

15, 000, COO

Following is a tabulation showing crop production for the Boise Valley for 1944, as shown in the 1944 census:

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State dairy department figures 1945, Ada and Canyon Counties

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FERTILITY OF VALLEY SOIL

The soil of Canyon and Ada Counties, which comprise the Boise Valley, is highly productive. Canyon County, through which the lower end of the Boise Rivers flows, was recently awarded the Army A award for the production of food for the Nation's war effort. Of the Nation's total 1942 production of seeds for 1943 Victory and commercial gardens, Canyon County alone produced 25 percent of the dwarf lima beans, 38 percent of the onion, 20 percent of all types of lettuce, 60 percent of the hybrid sweet corn and 43 percent of all garden sweet corn, 11 percent of the turnip, and 28 percent of the rutabaga. One out of every thirty-three pounds of garden seed used in America's Victory gardens in 1943 came from Canyon County.

FERTILITY OF RIVER BOTTOM SOIL

The lands lying immediately adjacent to the Boise River are perhaps the most productive in the valley.

Mr. Stanley Tucker, whose farm is on the river bank 5 miles west of Boise, has demonstrated this by the onion crops he has produced. In 1932 he produced 1,400, 100-pound bags per acre, and in 1935, 1,752 100-pound bags, or 175,200 pounds on a measured acre, of which Mr. Frank Gill, of the Gill Bros. Seed Co., Portland, Oreg., said: "This is probably the largest yield of onions per acre ever grown anywhere in the world."

Another illustration is Mr. R. H. Young, former president of the Idaho Public Utilities Commission and former commissioner of agriculture, who has produced outstanding yields on his farm on the banks of the river about 50 miles west of Boise. In 1910 he produced 358 tons of sugar beets on 10 acres. His onions ranged from 600 to 1,000 bags per acre, his potatoes from 150 to 400 bags per acre, head lettuce from 125 to 175 packed crates per acre. One year his yield was 350 packed crates per acre.

These are only two instances among many others which could be cited. In fact, the land adjacent to the river and the full length of the valley is all equally as productive as the two farms referred to. Under present conditions, however, with the constant threat of a flood hazard, too many of these river bottom farms are left in pasture and sod in order to prevent the topsoil from being washed away.

COOPERATIVE EFFORTS

As the urgent need for flood control on the Boise River became known, numerous local, State, and Federal agencies have cooperated wholeheartedly in an effort to find a solution to this problem. We think this cooperation is most commendable and praiseworthy. We wish especially to express our appreciation to the Corps of Army Engineers in the Department of War, the Bureau of Reclamation and the Geological Survey in the Department of the Interior, and the Soil Conservation Service and the Forest Service in the Department of Agriculture.

LUCKY PEAK

The Army engineers have now recommended a project which we believe will go a long ways toward solving the flood-control problems on the Boise River. We commend this project most heartily.

This proposed project, Lucky Peak Dam and Reservoir, would be situated on the Boise River about 11 miles above Boise. It would be of the rolled earthfilled type with a crest length of 1,700 feet. It will have a gross storage capacity of 306,000 acre-feet and 280,000 acre-feet capacity. The plan calls for the installation of a 13,000-kilowatt capacity power plant at Arrowrock Dam. This site, being below the mouth of More's Creek, will place the reservoir in a position to store the waters of all of the tributaries during flood season. The water thus stored can and undoubtedly will be made available for irrigation.

RECREATIONAL FEATURES

In the past too little consideration has been given to recreational possibilities in the designing and planning of projects for the control and use of water. The proposed plans include the construction of a road providing access to the reservoir with a park on a ridge nearby. The location of Lucky Peak Reservoir is

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