Its course is broken up by several reservoirs like Plutarco ElÃ as Calles ( El Novillo ) , LÃ zaro CÃ rdenas ( Angostura ) , or Ã lvaro ObregÃ n ( El OviÃ chic , Lake Ouiachic ) , which provides the water for the heavily farmed region of Ciudad ObregÃ n. Its course is interrupted by several reservoirs like Plutarco ElÃ as Calles ( El Novillo ) , LÃ zaro CÃ rdenas ( Angostura ) , or Ã lvaro ObregÃ n ( El OviÃ chic , Lake Ouiachic ) , which provides the water resource for the intensively irrigated region of Ciudad ObregÃ n.