Whisk together dry ingredients in a bowl, then add water, eggs, and oil and whisk until smooth. Let stand 5 minutes (batter will thicken). If batter is too thick to pour easily (whole-wheat flours vary in how much liquid they absorb), thin with additional water, 1 tablespoon at a time. Bring syrup with blackberries to a boil in a 1-quart saucepan over moderate heat, then boil, uncovered, stirring occasionally, 3 minutes. Remove from heat. Brush a griddle or 12-inch skillet with oil and heat over moderately high heat until hot but not smoking. Reduce heat to moderate. Working in batches of 4, spoon 2 tablespoons batter per pancake (a heaping large serving spoon works well) onto hot griddle to form 3- to 3 1/2-inch rounds. Cook until bubbles appear on surface and pop, edges are set, and undersides are golden, 45 seconds to 1 minute. Flip pancakes with a metal spatula and cook until undersides are golden and pancakes are cooked through, 45 seconds to 1 minute more. (Lower heat if pancakes brown too much before insides are cooked through.) Transfer pancakes to plates and brush griddle with oil between batches. Serve with warm syrup.