This paper proposes an approach to water flow method modification for text segmentation and reference text line detection of sample text at almost any skew angle. Original water flow algorithm assumes hypothetical water flows under only a few specified angles of the document image frame from left to right and vice versa. As a result of water flow algorithm, unwetted image frames are extracted. These areas are of major importance for text line parameters extraction as well as for text segmentation. Water flow method modification means extension values of water flow specified angle and unwetted image frames function enlargement. Modified method is examined and evaluated under different sample text skew angles. Results are encouraged especially due to improving text segmentation which is the most challenging process stage.