Flooded Venice has been hit by a new high tide of 160cm (5.3ft), giving residents no respite from a crisis costing millions of euros.
World-famous St Mark's Square, a magnet for tourists, has been closed, and schools are shut for a third day.
The Italian city's famous waterbuses – the vaporetti – have stopped running.
The 187cm peak on Tuesday was the highest level for more than 50 years, damaging cultural monuments, businesses and homes. More than 80% of the canal city was flooded.
The government declared a state of emergency in the Unesco world heritage site.
Residents with flood-damaged homes will get up to €5,000 (£4,300; $5,500), and businesses up to €20,000 in compensation.
Desperate measures as water seeps everywhere
The BBC's Jenny Hill in Venice writes:
The first flood sirens went off at dawn, an eerie sound rising over the ancient bridges and waterways of the city.
Within a couple of hours, the murky green water of the Grand Canal had risen level with its bank, slapping over the paving stones as boats went past.
Nearby streets quickly flooded. Tourists, shoes covered in plastic bags, carried their luggage along raised narrow trestle walkways, which the authorities have put up to keep the pedestrian traffic moving.
On either side, dirty water continued to rise. At ground level, in their rubber wellies, business owners were already starting to operate small pumps. Many had raised the flood barriers across their doorways – apparently to little effect. Water was already seeping up to ankle height in the souvenir shops and cafes.
"It hurts to see the city so damaged, its artistic heritage compromised, its commercial activities on its knees," Prime Minister Giuseppe Conte, who visited Venice on Wednesday, wrote in a Facebook post (in Italian).
The city has about 50,000 residents, but about 20m tourists visit every year.
The tides have been worsened by sirocco winds blowing from Africa, and there are fears that global warming is increasing the frequency and severity of such floods.
The government says Venice's elaborate flood defence system will not be operational until 2021 – yet work began on it back in 2003.