Officials in San Joaquin County and the Santa Clara Valley are taking steps to reduce water use in the face of continuing drought conditions that have lowered reservoir levels. In San Joaquin County, a local water emergency has been declared, and officials say rationing may be ordered later if voluntary conservation fails. In the Santa Clara Valley, water district officials warn that they may reduce or suspend pumping ground water if water customers do not cut back their use by 45%. The threat--immediately criticized as too drastic--was issued in an unprecedented drought response plan adopted by the Santa Clara Valley Water District. "What (the water district) is recommending sounds as dangerous as the drought," San Jose Vice Mayor Blanca Alvarado said. About a dozen cities and private water companies in the Santa Clara Valley get part or all of their water from ground water sold by the Santa Clara Valley Water District.