ranging from 500 cubic feet per second immediately downstream from Surplus Canal to 1,000 cubic feet per second below North Temple Street, and diverting all flows in excess of that amount to the west of the city via Surplus Canal and over the flood lands to the left of the canal into Great Salt Lake, levee construction and provision of control works just below the Surplus Canal, and enlargement of Surplus Canal to a capacity of 1,500 cubic feet per second, extension, and removal of obstructions, provision of a control structure at its head, levee construction along its northeast bank, and railroad-bridge extensions and construction at an estimated cost to the United States of $412.000; improvement of Little Valley Wash at Magna, Utah, provides for intercepting all flood flows at the mouth of the canyon above the town and conveying them through a new channel 5,800 feet long with a levee along its east side bordering Magna and other appurtenant works at an estimated cost to the United States of $222,000.

The estimated total first cost of these projects is $818,200, of which $184,200 is the estimated cost to be borne by local interests.

The CHAIRMAN. What is the population of Salt Lake, according to your report?

Colonel HERB. About 150,000 in 1940, sir.

Mr. ROBINSON. I think it is about 190,000 now.

Colonel HERB. For the Jordan River project the ratio of costs to benefits is 1.0 to 1.5; for the Little Valley Wash, 1.0 to 1.0.

In a letter from the Department of the Interior dated February 20, 1946, the Acting Secretary of the Interior stated that the proposed works would not conflict with any existing or proposed water-conservation projects and that the proposed improvements appear highly desirable. Also, the Governor of Utah, by telegram to the Chief of Engineers dated March 15, 1946, officially endorsed and approved the proposed improvements on Jordan River at Salt Lake City and the Little Valley Wash at Magna, Utah.

(The report of the Chief of Engineers, together with the comments of the Governor of Utah and of the Department of the Interior, are as follows:)

WAR DEPARTMENT,

OFFICE OF THE CHIEF OF ENGINEERS,
Washington, March 18, 1946.

Subject: Jordan River at Salt Lake City, Utah, and Little Valley Wash at Magna, Utah.

To: The Secretary of War.

1. I submit for transmission to Congress my interim report with accompanying papers and illustrations on preliminary examination and survey of Jordan River at Salt Lake City, Utah, and Little Valley Wash at Magna, Utah, in accordance with the Flood Control Act approved June 28, 1938, which authorizes preliminary examinations and surveys of "Streams draining into the Great Salt Lake and the Great Basin, Utah and Nevada." A final report on Jordan River will be submitted at a later date. Separate reports are being made on other streams covered by the authorization.

2. Jordan River has its source in Utah Lake, north central Utah, flows northward through a mountain gap known as the Narrows for 9 miles and thence continues north for 51 miles across the central part of Jordan Valley to Great Salt Lake. It drains 2,680 square miles tributary to Utah Lake and 615 square miles of Jordan Valley and adjacent mountains, a total of 3,295 square miles. Jordan Valley is a rectangular area of about 790 square miles of which 413 square miles are valley lands and the remainder foothills and mountains. It is surrounded by mountains except on the northwest where the flat lower lands border Great Salt Lake. About 15 miles south of Great Salt Lake, Jordan River flows through the westerly section of Salt Lake City. A considerable part of Jordan

Valley, to the west of Salt Lake City, drains directly into Great Salt Lake through small streams. Magna, Utah, is located in that area on the debris cone formed where Little Valley Wash, with drainage area of 6 square miles, debouches from the mountains. The flows of Little Valley Wash are intermittent and no well-defined natural channel exists to carry them across the debris cone.

3. Salt Lake City had a population of about 150,000 in 1940 and Salt Lake County about 212,000. War activities have resulted in a considerable increase in the population of the general region since 1940. Magna is an unincorporated mining and residential community with about 3,500 residents. Agriculture, transportation, mining, smelting, manufacturing, and the administration of Governmental functions are the principal occuptions in Jordan Valley. The more productive agricultural lands are located to the east of Jordan River and in the southern and southwestern parts of the valley. In general, the land along Great Salt Lake is inadequately drained and is used chiefly for grazing although some tracts are irrigated. Water for irrigation in Jordan Valley is obtained from Utah Lake via Jordan River, from the smaller streams which rise in the mountains and from wells. Several railroads, air lines, and a network of improved highways serve the area.

4. Jordan River within Salt Lake City is crossed by 21 bridges, 3 flumes, and 3 siphons and receives the discharge from 5 storm sewers. Five small flashboardtype dams are located in this section of the river. Three are used for irrigation diversions, one to create a cooling water pond for the Utah Power & Light Co., and the fifth, located where the river enters the city, was constructed to divert water into Surplus Canal but in its present inadequately maintained condition it is ineffective except when flows are low. Surplus Canal was constructed by local interests as a flood-control measure about 1885 and enlarged in 1917. It extends northwesterly for about 7 miles, diverts floodwaters past the city to the low marsh area bordering Great Salt Lake and also carries water for irrigation. It is crossed by 10 bridges, 4 flumes and a siphon and has a control dam at its head which is in poor condition and effective only for controlling low flows. Near its midpoint, the canal contains the North Point Consolidated Dam which provides for the diversion of water to irrigate farm lands northwest of Salt Lake City. At Magna local interests have constructed a concrete-lined channel, about 8,000 feet long, from the mouth of the canyon north along the west side of the town to carry the waters of Little Valley Wash to a storage and debris basin of about 100 acre-feet capacity formed by a ring levee. There is no existing Federal project for improvement of Jordan River or Little Valley Wash.

5. In spite of Surplus Canal, Jordan River at Salt Lake City is subject to destructive floods. The peak discharges almost always occur in spring or early summer and result from snow melt sometimes augmented by rain. All of the most important tributaries in Jordan Valley rise in the mountains and enter the river from the east. Several discharge through storm drains in the city section. Flows in the major tributaries are modified by various small storage reservoirs and diversions for irrigation. In recent years run-off below Utah Lake has been the principal factor in peak discharges. The district engineer finds that on rare occasions run-off from summer storms on the area below Utah Lake will produce floods with peak discharges in excess of those caused by snow melt. Utah Lake is utilized as a storage reservoir for irrigation water which requires pumping into Jordan River when the lake is low. Outflows from the lake are controlled by a dam in the Narrows. When the lake is below the established compromise level, little water is discharged except as required for irrigation. Since 1924, lake levels have been continuously below the compromise level. However, during periods of abnormal run-off and high-lake stages, lake outflows can substantially increase flood discharges at Salt Lake City. The observed maximum discharge from the lake since 1902 has been 1,370 cubic feet per second in 1922.

6. Flood records at Salt Lake City consist almost entirely of newspaper accounts and information from private sources. Within the city the channel of Jordan River is no longer an efficient drainage outlet due to the many obstructions and sediment deposits therein. There are places where a discharge of 350 cubic feet per second results in some overflow and a discharge of 1,000 cubic feet per second would cause a general overflow. Surplus Canal has a controlling channel capacity of about 1,100 cubic feet per second in its upper 5 miles within the city and 800 cubic feet per second farther downstream. The largest recent flood occurred in 1917 when the flow at the south city limits was about 1,800 cubic feet per second of which 1,000 cubic feet per second was diverted to Surplus Canal. The 800 cubic feet per second which flowed down the river through the city' was increased to about 1,000 cubic feet per second at North

Temple Street by tributary inflow.

A flood in 1922 attained a peak discharge of 1,550 cubic feet per second at the south city limits of which 960 cubic feet per second followed Surplus Canal and 590 cubic feet per second flowed down the river. Local inflow increased the river discharge to 940 cubic feet per second at North Temple Street. In addition, floods ranging from 550 to 750 cubic feet per second occurred at Salt Lake City in 1918, 1921, 1923, 1925, 1927, and 1929. Minor floods are an almost annual occurrence. Investigations of the district engineer indicate that at the head of Surplus Canal a peak discharge of 3,300 cubic feet per second may be expected with an average frequency of once in 100 years. Such a flood would inundate about 6.5 square miles within the city occupied by about 2,000 residences, 15 to 20 small business and industrial plants, a large power plant, highway and railroad facilities, 2 city parks, the State Fair Grounds, and irrigation canals. About 900 acres are agricultural lands. Lands subject to inundations by overflows from Surplus Canal are largely unimproved and resulting damages are not great. The district engineer estimates the future average annual direct and indirect flood damages at Salt Lake City from floods up to the largest to be expected with an average frequency of once in 100 years at $37,000.

7. Floods on Little Valley Wash at Magna are usually the result of summer cloudburst storms. Incomplete data indicate that at least seven floods have been experienced since 1922. The district engineer estimates that major floods may be expected with an average frequency of once in 10 years and a peak discharge of 3,900 cubic feet per second once in 100 years. Large floods usually fill the small artificial channel, which has a capacity of 250 cubic feet per second, with debris rendering it ineffective. About 580 acres are subject to flooding at Magna. The area includes some farm land north of the town, unimproved lands to its west, a park and recreational center in addition to about 600 residences, 70 business establishments, and various civic improvements. The district engineer estimates the average flood damages at Magna at $9,310 annually.

8. Local interests desire improvement of Jordan River through Salt Lake City, of Surplus Canal, and of Little Valley Wash at Magna to afford relief from flood damages, enhance property values, and encourage further development. They have indicated their willingness to furnish the required lands and rightsof way, to beat the costs of the necessary alterations of highways, irrigation structures, and other utilities except railroads, to operate and maintain the improvements after completion and to hold the United States free from damages due to the construction.

9. The district engineer reports that it would not be practicable to control floods in Jordan River by regulating the discharges from Utah Lake because the greater part of the damage through Salt Lake City is caused by floods originating below the lake and that no suitable sites for flood-control reservoirs are available. His plan provides for improvement of the river channel at Salt Lake City, a distance of 45,000 feet via the new alinement and enlargement of Surplus Canal. It includes an intercepting levee to guide floodwaters from above the city into the river channel at the head of Surplus Canal, a levee along the northeast side of the canal to prevent any canal overflows from entering the downstream city area and levees along the river through the city. For a short distance above Surplus Canal the river would be enlarged to a capacity of 2,000 cubic feet per second, thence to North Temple Street to capacity of 500 to 800 cubic feet per second and from that point to the lower end of the improvement enlarged and straightened to have a capacity of 1,000 cubic feet per second. Included is replacement of the diversion dam just below Surplus Canal, which would be operated so as to limit the flow in the river to the improved channel capacity. Any excess waters would follow the Surplus Canal, which would be enlarged to a capacity of 1,500 cubic feet per second, realined in minor respects, and extended a short distance at its lower end. During unusual floods Surplus Canal would continue to overflow onto the unimproved lands to its south, but little damage would result. The river work also includes substitution of pumping plants for the three irrigation dams, replacement of the power company's dam, extension of two highway bridges, and an irrigation flume, construction of a foot bridge, and lowering of a sewer. Additional work along Surplus Canal includes control works at its head, replacement of the irrigation dam, construction of three highway bridges, a railroad trestle, and an irrigation flume, and the extension of four railroad trestles, an irrigation flume, and a drainage siphon. The district engineer considers that local interests should furnish the necessary lands, bear the costs of all utility changes except for railroad bridges and except for the river and canal control works at their junction, hold the United States

free from damages resulting from the improvement, and maintain and operate the works after completion. On that basis he estimates the first cost to the United States at $412,000 for construction and to local interests for rights-of-way and utility changes at about $174,000, a total of $586,000. The estimated total annual cost is $30,740. Estimated annual tangible benefits consist of $37,000 for the prevention of flood damages, $1,960 for restoration of improved property values, and $7,500 for making unimproved lands suitable for a more valuable use, a total of $46,460. This indicates a ratio of costs to benefits for the work of about 1 to 1.5.

10. The major item of the district engineer's plan for improvement of Little Valley Wash at Magna consists of a channel 5,800 feet long extending from the mouth of the canyon along the west side of the town to the existing debris basin. The channel would have a capacity of 3,900 cubic feet per second, would be concrete lined in its upper 5,000 feet, where the slope is steep, and would be bordered on the town side by a levee. At its head channel crossings for a branch railroad, truck road, and a canal carrying water for irrigation and smelting and an entrance for a drainage canal would be provided, but damage from the resulting capacity of the debris pond would be exceeded, but damage from the resulting overflow would be slight. Costs to the United States for construction of the channel, levee, and railroad culvert are estimated at $222,000 and to local interests for rights-of-way, the flume, and road crossing at $10,000, a total of $232,000. Average annual costs and tangible benefits are estimated at $12,070 and $12,310, respectively. The district engineer considers that moderately large intangible benefits would also result as relief would be afforded from the present threat of floods.

11. The district and division engineers concur in recommending the improvement of Jordan River, Surplus Canal, and Little Valley Wash in accordance with the plans presented subject to the conditions that local interests furnish the lands required; hold the United States free from claims for damages due to the works; bear the costs of reconstructing, relocating or altering existing utility improvements except railroad bridges, and the proposed control structures at the junction of Surplus Canal and Jordan River; and agree to operate and maintain the works after completion.

12. The Board of Engineers for Rivers and Harbors agrees in general with the views of the reporting officers and recommends the proposed improvements at Salt Lake City and Magna, Utah, subject to the stated conditions of local cooperation.

13. After due consideration I concur with the Board and recommend improvement of Jordan River, Utah, at Salt Lake City, by enlargement, straightening, and removal of obstructive works from its channel, levee construction and provision of control works just below the Surplus Canal and improvement of Surplus Canal by enlargement, extension, and removal of obstructions, provision of a control structure at its head, levee construction along its northeast bank, and railroad bridge extensions and construction, in general accordance with the plans of the district engineer as shown on the accompanying drawings with such modifications thereof as in the discretion of the Secretary of War and the Chief of Engineers may be advisable, at an estimated cost to the United States of $412,000 for construction; and improvement of Little Valley Wash at Magna, Utah, by construction of a channel about 5,800 feet long with a levee along its east side bordering Magna and by related work, in general accordance with the plans of the district engineer as shown on the accompanying drawings with such modifications thereof as in the discretion of the Secretary of War and the Chief of Engineers may be advisable, at an estimated cost to the United States of $222,000 for construction; provided that no work shall be undertaken at either of the two localities until, for the improvement concerned, responsible local agencies have given assurances satisfactory to the Secretary of War that they will (a) provide without cost to the United States all lands, easements, and rights-of-way necessary for construction of the works, including in this provision the undertaking of all necessary alterations and constructions of highway facilities, irrigation works, and other utilities except railroad bridges and except control structures at the junction of Jordan River and the Surplus Canal, (b) hold and save the United States free from damages due to the construction works, and (c) maintain and operate all the works after completion in accordance with regulations prescribed by the Secretary of War. R. A. WHEELER, Lieutenant General, Chief of Engineers.

[Telegram]

SALT LAKE CITY, UTAH, March 15, 1946.

CHIEF OF ENGINEERS, Washington, D. C.: Have had our engineers carefully examine interim report on Jordan River at Salt Lake City and Little Valley Wash, Magna, Utah. They are enthusiastic over report. We sincerely appreciate your efforts and will support you in your recommendations.

Lt. Gen. R. A. WHEELER,

HERBERT B. MAW.

Governor of Utah.

DEPARTMENT OF THE INTERIOR, Washington 25, D. C., February 20, 1946.

Chief of Engineers, War Department.

MY DEAR GENERAL WHEELER: On November 30, 1945, you transmitted to this Department a copy of your report on Jordan River at Salt Lake City, Utah, and Little Valley Wash at Magna, Utah."

I have reviewed the report and find that the proposed flood-protection works do not conflict with any existing or proposed water-conservation projects. The improvements recommended are for an alleviation of local flood problems and appear to be highly desirable for that purpose.

Sincerely yours,

OSCAR L. CHAPMAN, Acting Secretary of the Interior.

Mr. ROBINSON. I think it should be noted that while you mention Salt Lake City, it really covers the entire county of Salt Lake, and none of this is within several miles of the populated area of the city. It is outside of the populated area. It happens that Salt Lake City owns some of these lands west of the city. So it is really a project that includes all of Salt Lake County.

Colonel HERB. That is correct, sir.

Mr. ROBINSON. I want to recommend this project to the committee. I am glad to know that it has gone along as far as it has. I think it is a very worthy project.

The CHAIRMAN. Mr. Robinson, generally, would you say that local interests out there are prepared to furnish the rights-of-way?

Mr. ROBINSON. The local interests are extremely interested in this, as the Governor's letter suggests. There will be no question about the cooperation of the people there. They will do whatever they can and whatever is required to help in this matter.

The CHAIRMAN. Is there any reclamation presently along the Jordan River?

Mr. ROBINSON. Not that I know of.

Mr. DIXON. Mr. Chairman, there is reclamation in that area, but we think this project will be highly beneficial.

The CHAIRMAN. There is reclamation in the Jordan Valley area? Mr. DIXON. Some water is diverted from the Jordan River and used in adjacent lands.

Colonel HERB. Surplus Canal, which diverts floodwaters past Salt Lake City, also carries water for irrigation. Surplus Canal was built by local interests back in 1885, according to the records we have.

The CHAIRMAN. Has the Federal Government any reclamation there?

Mr. DIXON. Yes, sir.