SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSH. CULTURAL RESOURCESBy about 1810, all native Californians had been sent to the missions. During the mission period,the Costanoans were subjected to disease, and their native lifestyle was completely converted toan agricultural economy based at the missions. Eventually, the population of the Costanoansdwindled as the young adults moved away, the elders died, and the land was acquired bynonnative people.Mexican PeriodDuring the Mexican period, approximately 65 land grants were issued in Alameda and SantaClara Counties, including the 48,436-acre Rancho el Valle de San Jose in Alameda County. TheAlameda Watershed is located in the southern portion of this ranch. This ranch was granted tothe Bernal family, was divided among family members, and portions were later sold to AntonioSunol. The Alameda Watershed is situated in the Sunol portion of Rancho el Valle. By 1840,the Sunol homeplace was established in the vicinity of the present-day Sunol Water Temple, andconsisted of an adobe and associated outbuildings and facilities on the banks of Alameda Creek.This ranch is the only known historical remain within or immediately adjacent to the AlamedaWatershed that is associated with the Mexican period.American PeriodAfter California became part of the United States in 1848, there were numerous disputes over thevalidity of Mexican land grants, and the Bernals and Sunols, owners of Rancho el Valle deSan Jose, were plagued by an onslaught of settlers. Portions of the ranch were sold, leased, ortaken over by squatters. By the late 1870s, much of the ranch land within the AlamedaWatershed had passed to other parties. The Watershed lands were productive farmlands andsupported grain fields (including wheat, barley and alfalfa), vineyards, and orchards, with a fewhundred farmers and ranchers living in the region. As the Sunol Valley filled with farms, peoplemoved farther into the mountains, and there were six, one-room schoolhouses scattered throughthe Watershed lands during the late 1800s and early 1900s.However, to meet the growing water needs of San Francisco, the Spring Valley Water Companybegan acquiring water rights and purchasing land in the Calaveras and Sunol Valley region in the1870s to augment the water system in San Mateo County and San Francisco. The water companywas aggressively purchasing land in the Watershed area from 1874 through 1913. Constructionof the water system in the Alameda Watershed began in 1887 with the diversion of AlamedaCreek, followed by the underground filter galleries. Construction of Calaveras Dam began in1913 and was completed in 1925. Other facilities constructed during this period included theSunol Water Temple, groundwater wells in Pleasanton, the Sunol Aqueduct, and the AlamedaDiversion Tunnel and Dam.In 1930, the Spring Valley Water Company officially sold its properties and facilities to theSFPUC, which currently owns, operates, and maintains the system. The Alameda Watershedwater system was connected to the Hetch Hetchy system through construction of the Coast RangeTunnel in 1934 and to the Peninsula Watershed system that same year. The San AntonioNOP 96.223E: Alameda Watershed Management Plan III.H-2 ESA / 930385January 2001