Sacramento Bee: Any doubt that California is hip-deep in an epic struggle for water was put to rest earlier this month when an estimated 10,000 farmers and farmworkers marched 50 miles across the gasping San Joaquin Valley. The goal was to heighten awareness about their water shortage, brought about by a third year of drought in California and environmental problems in the Sacramento-San Joaquin Delta. Their alliance is surprising, given a long history of acrimony between farm owners and laborers. It …