B08__A7_Concrete_Technical_Memorandum_1.pdf

This technical memorandum documents a concrete condition assessment for the Wapato Drop 1 Pumping Plant's hydro turbine forebay intake area, conducted by Jacobs Engineering Group for the Bureau of Indian Affairs. The assessment involved visual inspection, crack mapping, and core sampling of concrete elements, focusing on the water screen and intake areas.

Key findings include: generally satisfactory concrete condition with temperature and shrinkage cracking observed; concrete strength tests showing high compressive strength (over 4,000 psi for walls, over 5,000 psi for floor); and evidence suggesting the floor slab was not original to the 1920s construction. Recommendations include investigating a potential void/sink hole area, rehabilitating or replacing concrete in certain locations, and replacing existing steel trash rack panels and intermediate supports due to poor condition. The report suggests these repairs should be completed prior to the new water screen project to ensure structural integrity.