In a saucepan, boil potatoes until they are fork tender (cooked but not too mushy). Drain and set aside. In a soup pot, saute bacon until almost fully cooked. Drain the grease. Add the onions, celery and butter. Continue to saute on medium heat until transparent. Add flour and simmer 5 minutes stirring constantly but do not let it brown. Add the water, milk, potatoes and corn. Add pepper to taste. Bring to simmer again for about 10 minutes. If you would like to thicken the chowder a little more, put 1 Tbsp. corn starch in a bowl and mix in just enough water to dissolve it. Pour cornstarch slowly into simmering chowder stirring constantly until desired thickness is achieved.