For filling, in a medium saucepan combine berries, sugar, water, lemon juice and 1/2 teaspoon cinnamon. Bring to a boil. Reduce heat. Simmer, uncovered, for about 8 minutes or till slightly thickened, stirring frequently. Remove from heat.
In a mixing bowl stir together flour, oats, brown sugar, 1/4 teaspoon cinnamon, and baking soda. Stir in melted margarine till thoroughly combined. Set aside 1 cup of the oat mixture for topping. Press remaining oat mixture into an ungreased 9x9x2" pan. Bake in a 350 oven for 20-25 minutes.
Carefully spread filling on top of baked crust. Sprinkle with reserved oat mixture. Lightly press oat mixture into filling.
Bake in the 350 oven for 20-25 minutes more or till topping browns.