This is very interesting puzzle. I saw this puzzle first time on "Puzzle Picnic" website. This puzzle was part of Indian Puzzle Championship 2011. All the puzzles in the qualifying round of "Water Fun" puzzle type were created by me. Again all the puzzle which I created were very easy.
"Water Fun" Puzzle Instructions:
Fill water in some parts of the grid. The numbers below or next to the grid indicate how many squares of each row or column must be filled with water. Connected areas of filled cells must have same surface height everywhere – even if the surface is not connected, like in a U-shaped tube.