The Yamuna river was flowing almost a metre above the danger mark and it may swell even further as Haryana released more water from a barrage on Tuesday afternoon.
However, Delhi Chief Minister Arvind Kejriwal said the current situation in under control.
According to a Delhi government official, the river breached the danger mark of 205.33 metres on Monday and was flowing at 206.40 metres at 9 pm on Tuesday.
He said Haryana released 25,590 cusec and 21,006 cusec of water from the Hathinikund Barrage at 5 pm and 9 pm respectively. The water level in the Yamuna is likely to reach 207.08 metres between 2 pm and 4 pm on Wednesday.
The Northern Railway has suspended the movement of trains between Old Delhi and Delhi Shahdara stations. Now, trains will be diverted via New Delhi railway station, a spokesperson said.
In view of the rising level of water, authorities in Delhi have already shut the Old Iron Yamuna Bride for vehicular traffic.
Senior scientist at Indian Meteorological Department Kuldeep Srivastava said rain is likely to subside in Uttarakhand and Himachal Pradesh over the next four to five days, leading to an improvement in the situation in Delhi.
"The situation in Delhi is likely to persist for another two days. If there's no further discharge from the Hathinikund barrage, the water level in the Yamuna will drop," he said.
Mr Kejriwal told reporters on Tuesday afternoon, "We have come to know that the Yamuna river is flowing at 206.20 metres. Currently, the situation is under control."
To a question on encroachments on the floodplains of the Yamuna river, he said the Delhi government will look into it.
The river flows through six districts of Delhi whose low-lying areas are prone to flooding. The administration has deployed 30 boats to prevent accidental drowning.
The Delhi government has also set up tents opposite Mayur Vihar Extension to accommodate around 23,000 displaced people during flooding.
Delhi Revenue Minister Kailash Gahlot inspected the relief camps set up by Delhi Government at Haathi Ghat and Kanchan Colony.
"Inspected relief camps at Haathi Ghat and Kanchan Colony set up by Delhi government. Interacted with people who have been evacuated and now staying in relief camps. Have directed DMs to ensure availability of all the relief materials," he tweeted.
A government official said of the 15,000 people moved out of the Yamuna floodplains, 10,500 have been putting up in 2,300 tents and no untoward incident has taken place.
In 1978, the water in the river had risen to its highest-ever level of 207.49 metres, causing a devastating flood in the national capital.