Proposed Improvements 



Authorization for improvements at Noyo River and Harbor was granted 

 by the River and Harbor Act of 1962. Under this authorization, however, 

 breakwaters were proposed to protect the outer cove for development. 

 The massive breakwaters required were not economically feasible (due to 

 the high cost of construction and maintenance), resulting in the project's 

 being transferred to an inactive category. The Water Resources Develop- 

 ment Act (WRDA) of 1976 modified the 1962 project to provide for con- 

 struction of up to two breakwaters without a specific location to protect 

 the harbor entrance (USAED, San Francisco 1979). The location of break- 

 waters in more shallow water would reduce construction cost signifi- 

 cantly. The 1976 WRDA also included additional channel improvements 

 (deepening, widening, and extending) as deemed necessary, subject to ap- 

 plicable economic and environmental criteria. 



Previously Reported Model Tests and 

 Conclusions 



The Noyo River and Harbor model was constructed initially to investi- 

 gate both short- and long-period wave and river-flow conditions in the 

 river and harbor for comprehensive test conditions. Qualitative informa- 

 tion on the effects of the proposed breakwaters on sediment moving down 

 the river also was provided. Details of the investigation were published in 

 Bottin, Acuff, and Markle (1988). Conclusions derived from results of 

 these tests are mentioned below. Plan numbers in the following subpara- 

 graphs refer to the previous investigation. 



a. Existing conditions are characterized by very rough and turbulent 

 wave conditions in the Noyo River entrance during periods of storm 

 wave attack. 



b. Deepening of the entrance channel will not improve wave conditions 

 in the existing river entrance, considering all test conditions. 



c. The originally proposed breakwater location (Plan 3) resulted in 

 excessive wave heights (up to 8.8 ft) in the river entrance. 



d. Of the 40 expedient rubble-mound breakwater plans (Plans 5 

 through 42) tested, the alignment of the 637-ft-long breakwater of 

 Plan 39 appeared to be optimum with regard to wave protection, 

 navigation, and economics. 



e. The 637-ft-long dolosse breakwater of Plan 43 (same alignment as 

 Plan 39) was selected as the optimum improvement plan for 

 protection of the Noyo River entrance. 



Chapter 1 Introduction 



