In a large mixing bowl, cream the butter, peanut butter, sugars and the water. Beat in the eggs, one at a time, and vanilla. Combine the flour,oats, baking soda and salt;gradually add to the creamed mixture.
Spread into a greased 15x10 inch baking pan. Bake at 325 for 18-22 minutes or until lightly browned.
For glaze: In a microwave safe bowl, melt chips and peanut butter; pour over warm bars and spread evenly. Cool completely on a wire rack before cutting.