 Before the canal average discharge of the Merkys is and below it only .At the end of the 19th century the drainage basin of the Merkys grew by some as its tributary Ūla overtook some of the Kotra's watershed area.The Merkys is a popular destination among water tourism enthusiasts as part of it belongs to the Dzūkija National Park and it flows into the Neman near the historical site of Merkinė.