Preheat oven to 350 degrees. Grease well a 9" x 13" baking pan.
In mixer bowl, cream together the butter and the sugar until light and fluffy. Mix in the water, eggs, oil and vanilla extract; mix well. Add in the cake mix and mix well. Fold in the nuts and chocolate chips. Spread evenly into prepare pan.
Bake for 35 to 40 minutes, until edges are golden and toothpick tests clean in middle.