Washington 25, D. C.,
December 21, 1953.

Maj. Gen. S. D. STURGIS, Jr.,
Chief of Engineers, Office of the Chief of Engineers,
Department of the Army, Washington 25, D. C.

DEAR GENERAL STURGIS: This is in response to letter of October 9, 1953, from the Acting Chief of Engineers supplying for our information and comment copies of your proposed report on a review of report on San Lorenzo Creek, Calif.

The report sets forth a recommended plan for the improvement of San Lorenzo Creek in the interest of alleviating the serious flood control problem in the area. Under the plan the channel would be improved from San Francisco Bay to the B Street Bridge in Hayward, at an estimated Federal first cost of $3,644,000 and an estimated non-Federal first cost of $631,000, or a total first cost of $4,275,000. Federal participation would be subject to several conditions of local cooperation, including among others, the provision of assurance that local interests will prevent encroachment on the project channels which might interfere with their proper functioning for flood control. Federal participation in the construction of possible multiple-purpose, or flood-control dams in the basin was found not justified.

Several agencies of the Department have reviewed the report and our comments follow:

The proposed project does not conflict with present or future plans of the Bureau of Reclamation. The water-conservation aspects of the plan appear satisfactory and it is hoped that future agreements will contain similar provision to prevent flood-channel encroachments.

The Geological Survey has noted that the proposed plan of channel improvement includes provision to permit infiltration of water from the channel into the underlying aquifers substantially as under existing conditions. Opportunity for percolation of a portion of the flood runoff into the shallow aquifers in hydraulic connection with the channel would be provided by outlets or open holes in the concrete channel. Thus, the only possible detrimental effect of the project on ground water, namely, the lessening of influent seepage after lining the channel, would appear to be offset through provision of the infiltration holes.

As is indicated in appendIx V the principal concern of the Fish and Wildlife Service is that of providing for passage of steelhead trout to and from their spawning grounds. It is noted that sufficient opportunities will exist during the planning and design stages of the project to permit the Service and the California Department of Fish and Game to work closely with the district engineer in developing solutions to fishery problems to the extent practicable.

Other interests of the Department will not be affected by the project recommended in the report. We are glad to advise you that the proposed project should contribute effectively to alleviating flood damages in this area.

We appreciate the opportunity of reviewing the report.

Sincerely yours,

Assistant Secretary of the Interior