Work will begin in August to raise the concrete lining of the California Aqueduct in the Antelope Valley, the state Department of Water Resources said. Construction on the 21-mile section will take about eight months and cost $5.7 million, the department said. During construction, fishing sites and access to that section will be closed. The work is designed to increase the aqueduct’s capacity and to improve operational flexibility of the California Water Project. Future construction on other parts of the aqueduct’s east branch will continue until 1990 or beyond, the department said.