History Monticello Dam

the lower section of lake berryessa near portuguese canyon, seen looking upstream

the solano project first took shape in 1940s after formation of solano irrigation district manage water resources of putah creek. on november 11, 1948 secretary of interior formally authorized project, constructed bureau of reclamation. bureau intended incorporate project part of larger central valley project (cvp), manage combined watersheds of sacramento , san joaquin rivers. however, locals favored solano financed , operated separately cvp. senate hearing in 1953 confirmed solano constructed independent project.

land purchases in future reservoir area made in 1953; however, landowners allowed stay throughout construction period until property flooded rising lake levels. inhabitants of berryessa valley vehemently opposed project, did city of winters (one of would-be beneficiaries of project) because of close social ties town of monticello. opponents of big dam proposed series of smaller reservoirs constructed supply water, deemed uneconomical. of monticello s residents moved out summer 1956, rising waters approached town. after area vacated, crews deforested valley , demolished existing buildings , infrastructure. 300 graves had relocated higher ground.

the primary construction contract awarded consortium formed peter kiewit sons co. , parish brothers, construction of main dam , relocation of california state route 128, ran through berryessa valley. excavation of dam site , construction of diversion tunnel continued through 1954, first concrete placed on august 9, 1955. despite major flooding between january , may 1956, more 90 percent of concrete had been laid december 1956, , dam topped out on november 7, 1957, @ total cost of $37 million. figure includes cost associated downstream irrigation works , highway relocation.

the reservoir took 5 years fill after construction, reaching capacity first time on april 18, 1963. reservoir inundated monticello (though city s ruins visible @ low water levels), , flooded 20,700 acres (8,400 ha) of surrounding berryessa valley. @ time, lake berryessa second-largest volume reservoir in california, after shasta.

the reservoir has become popular summer recreation area, attracting many 1.3 million visitors each year. bureau of reclamation operates 5 recreational areas around lake, providing boat ramps , day use facilities. recreational use has been declining since 2012, due budget problems have forced closure of local resorts. has caused economic collapse of surrounding area, causing many residents move away.