Guardian: Bill Diedrich, a fourth-generation almond grower in California’s Central Valley, expects that many of his trees won’t make it through the year. “It’s one of the grimmest water situations we’ve ever faced,” he said. “It’s an absolute emergency and anything to get water flowing quickly is needed.” The 400-mile Central Valley is many things: the world’s largest agricultural area; the “salad bowl”, where half of the country’s vegetables are grown. But this year, with water shortages of a …