Document:
Excerpts from Document 544

This document was submitted by the U.S. Army Corps of Engineers to Congress in March, 1938.

191. Flood control.-Due to rainfall and runoff characteristics in the Willlamette Basin to limited high-water channel capacities on the Willamette River and its major tributaries, and to the broad, flat valley-floor formation, a serious flood problem exists in the basin. The flood hazard is especially serious along the stretch of the main Willamette River between Springfield and the mouth of the Yamhill River and along the lower reaches of its tributaries. The importance of the flood problem is not however, generally appreciated because of the subnormal rainfall and run-off conditions that have occurred during the past 30 years. With the return of a cycle of wet years such as has occurred in the past and will again occurring the future, a large and recurring damage will ensue to present rural and urban developments in the basin. This damage will tend to increase with further agricultural and industrial expansion. It may be noted that the average annual damage that may be expected is not due primarily to relatively infrequent recurring high flows but rather to frequent overflow from normal floods.

192. Complete protection of the areas in the basin subject to over-flow, either by a system of levees alone or by a combination of reservoirs and levees, is not now warranted by the resultant benefits. Partial protection of the most important areas, as considered herein, can be obtained either by a system of levees or by the storage of flood waters in reservoirs located on the major flood-producing tributaries. If all storage costs had to be carried by flood control, levees for such partial protection would be more economical than reservoirs and could almost be justified by the resultant benefits. However, as approximately 65 percent of the storage provided for flood control can be utilized to serve other purposes which can carry a part of the storage cost, the most economical plan for over-all coordinated development necessitates the construction of such reservoirs for multiple use. If such reservoirs are constructed, no additional large-scale supplement levee improvements are now considered justified.

193. Navigation.-Further navigation improvements on the Willamette River must be largely justified by benefits that may be expected to accrue to future down-bound log traffic over an improved river. Detailed analysis and study indicates that the Willamette Basin timber stands form the most economical source of log supply for the mills in the Portland-lower Columbia River area after these mills exhaust their present source of log supply. The lower Columbia River timber stands, now furnishing the major portion of the logs utilized by these mills, are rapidly becoming depleted, and importations from the Willamatte Basin have already commenced. Further utilization of Willamette Basin logs may be expected to increase rapidly. Other movements of heavy bulk freight are not likely, but some tonnage or miscellaneous general commerce maybe expected to develop.

194. For the anticipated traffic controlling depth of from 5 to 6 feet is considered adequate, and added depth will have little value; adequate channel to Albany can be obtained either by means of locks and dams or by increasing the low-water flow by releases from upstream storage reservoirs supplemented by dredging. Slack-water improvements to Albany, estimated to cost a approximately $140,000 per mile are on the verge of economical feasibility. Open river improvements to Albany by increased stream flow cannot be justified if storage costs must be carried by navigation alone. However coordinated operation of the proposed flood-control reservoirs will make available sufficient water to maintain, with supplementary open river improvements, a satisfactory navigable depth to Albany. Navigation improvements above Albany necessitate the construction of locks and dams. The cost of such improvements to Eugene, estimated from $260,000 to $405,000 per mile, are not warranted the resultant benefits.

195. Utilization of the Willamette River for large-scale downstream log movement is dependent upon the provision of modern lockage facilities at Willamette Falls as well as upon channel improvements in the river section above. If further improvements are undertaken on the Willamette River in the interest of navigation, the first step should be the reconstruction of the existing Willamette Falls locks, outlined herein, in order to facilitate present downstream log traffic which largely originates in the area tributary to the existing slack-water pool extending from Oregon City to Newberg.

196. Irrigation. --Supplemental irrigation during the summer months when rainfall is deficient would be of material benefit to the agricultural lands in the basin. In many areas drainage improvements would be necessary in connection with such irrigation works. Due to the fact that most of the agricultural lands are in small, privately owned farm tracts and to the fact that an average farm can show a profit under present dry farming methods, large-scale gravity-irrigation developments are largely dependent upon cooperative organization and low costs of development. Some of the irrigab1e areas under consideration could, if adequate water and low power rates were available, be economically developed in small tracts by pumping from ground water. Future irrigation developments of the latter type will be dependent upon the markets available for specialty crops.

197. Pursuant to the foregoing, further investigations are needed before extensive distribution systems are undertaken to determine the demand for irrigation in the basin as measured by the amount that prospective users could afford to pay toward irrigation improvements to obtain a supplemental water supply. Further data are also needed on ground-water conditions under the valley floor in order to arrive at an accurate comparison between gravity irrigation costs and irrigation by pumping from ground water.

198. Power.-The rate at which the hydroelectric resources of the Willamette Basin will be developed is dependent not only upon future requirements but also upon the cost of Columbia River hydro power which may be imported into the basin. When hydroelectric development in the basin become justified by power requirements and economic considerations, such developments can be economically undertaken in steps, as warranted by market conditions, at and below the proposed reservoirs on the power tributaries.

199. Although the propose Lookout Point Reservoir on the Middle Fork is one of the most expensive storage sites in the basin and its ultimate power value is the least of any of the three power reservoirs under consideration, its inclusion as a power reservoir in the "coordinated plan" appears advisable for the purpose of conserving the resources on the lower Middle Fork. However, if use of this reservoir for power conservation and development were not important in a of coordinated water use, the alternate reservoirs discussed in graph 77 as possible substitutes for Lookout Point might be advantageous.

200. Stream Purification. -Stream pollution along the lower SE of the Willamette River during the summer and fall months, when natural stream flow is low, is now a serious and pressing problem. Further industrial expansion and population growth will aggravate present unsanitary conditions, which are considered to be nuisance and a detriment to public health. Regulation of the main stream in the interest of navigation would tend to temporarily alleviate present situation by increasing present low-water flows. However, with continued development of the Willamette Basin, domestic and industrial wastes will eventually require partial or complete treatment before being discharged into the stream channels.

201. Multiple-use projects.-- Seasonal rainfall and run-off conditions and water demands in the Willamette Basin are exceptionally favorable to the formulation of a water-conservation plan involving multiple-uses. Accordingly, plans developed on the basis of coordinated rise present the most economical basis for over-all development for the benefit of all interests affected. This can best be illustrated by the following table which shows comparative cost estimates of obtaining the same improvements both by coordinated storage developments and supplemental improvements, as outlined herein under the "initial development," and by the most economical method of independent developments. For the purpose of direct comparison the items incorporated in the proposed reservoir in the interest of future power use have been omitted from the cost estimates With the exception of incidental benefits to stream purification and to existing power developments on the main stream which would be greater under a plan of coordinated use than under a plan of independent use, the resultant benefits for the two alternate methods of development are the same.

202. Local cooperation. - At the public hearing held in connection with this report local interests generally expressed a willingness to comply to the extent of their ability with the terms of local cooperation required by the Flood Control Act of 1936. However, it is not believed that they would be able to assume the cost of railroad relocation involved in the proposed reservoir construction, nor should they be hailed upon to do so in view of the navigation benefits that would accrue to the general public and the fact that a considerable part of the investment in reservoirs should be repaid by sale of water for irrigation and eventually by sale of power; also it is believed that the proposed reservoirs should be maintained and operated by the United States in order to protect the general public interest in navigation and power development. With the reservoirs maintained and operated by the United States, local interests cannot very well assume liability for damages. Preservation of fish life on the Willamette River and tributaries is an interstate, if not a national, matter, and for this reason it is believed that the cost of reconstructing fish hatcheries and other facilities for the propagation of fish should be by the Federal Government. Increased costs of operation and maintenance, if any, should be absorbed by the agencies now operating such facilities.

203. Conclusions.-Further improvement of the nontidal section of the Willamette River is advisable in the interest of general commerce and navigation. There is urgent need for additional protection against floods in the Willamette Valley. Rainfall in the Willamette Valley is deficient during the growing season, and provisions for supplemental irrigation on a larger scale should be made in order to bring about full development of large agricultural resources valuable from the national standpoint. Steam pollution is fast becoming a problem calling for remedial action. Power development is not now needed but provisions should be made at this time to insure full realization of power resources in the future. The cost of adequate independent improvement in the combined interest of navigation and flood control, with due regard to provision of water doe irrigation, stream purification and future power development as outlined in this report, for the initial development under a coordinated plan of water conservation appears to be practicable and economically feasible. It is believed that the United States would be justified in undertak9inf such improvement provided suitable cooperation on the part of local interests is forthcoming. If this improvement is carried out, adequate facilities for navigation will be afforded, the ever-present danger of great loss of life and property from the recurrence of a major flood will be eliminated, and the ground work will be laid for the orderly development of irrigation and power as warranted by economic and financial conditions.

204. Recommendations. - It is recommended that the existing navigation and flood-control projects for the Willamette River and tributaries, Oregon, be modified so as to provide for construction of a system of reservoirs and regulation of stream flow as outlined in this report; for such channel in improvement and construction as may be necessary to secure, with stream-flow regulation, controlling depths of 6 feet to the mouth of the Santiam River and 5 feet to Albany and for reconstruction and enlargement of the locks at Oregon City as outlined in this report; subject to the provision that the State of Oregon and/or local interests shall furnish free of cost to States, the necessary lands, easements and rights-of-way, except those required for railroads and facilities for preservation of fish. The estimated additional cost to the United States is new work and $365000 per annum for maintenance. The estimated cost of lands, easements and rights-of-way to be borne by local interests which includes highway relocation is $1O,134,O0O.

THOMAS M. ROBBINS

Colonel, Corps of Engineers, Division Engineer

back