Design for Entrance Channel Navigation Improvements, Morro Bay Harbor, Morro Bay, California

A 190 scale, three-dimensional hydraulic model was used to investigate the design of proposed entrance channel depth modifications at Morro Bay Harbor, California, with respect to navigation conditions. The impact that the proposed depth changes may have on wave conditions at the existing structures and the spit between the south structures also was addressed, and sediment tracer patterns were obtained in the entrance. The model reproduced the harbor entrance, approximately 7,000 ft of the California shoreline, and offshore bathymetry in the Pacific Ocean to a depth of 60 ft mean lower low water mllw. A 60-ft-long unidirectional, spectral wave generator, an automated data acquisition system, and crushed coal tracer material were utilized in model operation. It was concluded from results that a For the existing harbor entrance, operational waves 8 to 16 ft in height from the predominant 275 deg direction resulted in hazardous entrance navigation conditions due to wave steepening andor breaking. b For the originally proposed improvement plan Plan 1, navigation conditions in the entrance were improved for operational waves from 275 deg however, the plan resulted in significantly increased wave heights which may cause damage to the head of the south breakwater during extreme wave conditions waves ranging from 21 to 30 ft in height. Breakwaters, Hydraulic models, HarborsCalifornia, Morro Bay HarborCalifornia, Harbor shoaling, Navigation.