Six consecutive years of drought have left Moroccan dams at critical levels, prompting a big drop in the area of land being irrigated, Morocco’s water and agriculture ministers said. By mid-January, Morocco’s average dam filling rate had dropped to 23.2% from 31.5% a year earlier, water minister Nizar Baraka told a meeting on Tuesday, according to a royal palace statement. Rainfall was 70% lower than in an average year, he said. The country’s second biggest dam, Al Masira, which serves the economic hub of Casablanca, is almost empty. The worst drought in more than two decades prompted authorit…