1. Process water, milk, butter, and salt in food processor; add flour and process until smooth. Transfer to glass measure.
2. Coat a 7-inch nonstick skillet with cooking spray; heat over medium-high heat. Fill a 1/4-cup measure halfway with batter; add to pan, tilting to cover bottom. Cook 1 minute; loosen edge and turn out onto paper towels (crepe should be just lightly colored). Repeat, making 11 more crepes.
3. Spread 1 rounded teaspoon creme fraiche down center of one crepe. Top with 2 strips salmon and 1/4 teaspoon each dill and caviar. Fold in sides and roll up. Cut on diagonal in half. Repeat. Cover; refrigerate up to 1 hour. Makes 24 servings.