Warsaw braced Monday for a new flood crest on the mighty Vistula river, as Budapest sandbagged its tourist quarter against the swollen Danube and Slovakia reeled from its worst flood in centuries. Heavy rains pounding central and eastern Europe have broken defences all along the Vistula, Poland's largest river which winds from the mountainous south to the Baltic Sea in the north, causing weeks of flooding. The crest, or high point of the flood, is moving north and is forecast to surge into the Polish capital in the early hours of Wednesday, two weeks after a first giant wave washed through the capital. 'The second large wave will arrive in Warsaw around 0300 CET (0100 GMT) at 7.8 metres (8.5 yards),' Mieczyslaw Ostojski, head of the IMGW weather institute, told reporters. Warsaw officials launched a new alert for the city of two million, which was spared serious damage from the flood in May. 'It's a fresh challenge for all of us,' Warsaw Mayor Hanna Gronkiewicz-Waltz told reporters Monday. A Warsaw motorway running along the river will be closed to traffic from Monday midnight, as will around 150 schools that would be threatened by flooding should defences along the river rupture, the mayor said. Tens of thousands of people whose homes are threatened have been evacuated in recent days in southern regions of Poland. Floods which have plagued Poland since mid-May have dominated the campaign for the June 20 snap presidential election, with weather officials forecasting more storms in southern Poland in the coming week. In neighbouring Slovakia, authorities said Monday they had started to distribute money from a 25-million-euro (30-million-dollar) package earmarked for people hit last week by the worst floods in centuries. 'Depending on the level of damage they suffered, families will get 300, 1,000 and 3,000 euros to provide for their basic needs in the first days after floods,' Interior Minister Robert Kalinak told journalists. Floods in Slovakia have caused landslides and disrupted transport, reportedly killing three people and forcing thousands out of their homes in the east and south of the state of 5.4 million. Water levels on most rivers had receded by Monday morning, leaving railways and roads damaged, and dozens of houses torn down. Slovak Prime Minister Robert Fico has said the government would appeal to the European Union solidarity fund for help, but the interior minister said the floods would not disrupt the general election set for June 12. Three weeks of flooding have also caused severe destruction in Hungary, mostly in the northeast, where one person was killed at the weekend and some 4,000 people were evacuated on Sunday evening. In Budapest, the Danube was expected to reach 8.2 metres Monday evening, before starting to recede from Tuesday. The river embankment has been closed to traffic, along with parts of the public transport network, while the tourist area of Margaret Island and parts of the old city of Buda have been protected by sand bags. More than 20,000 people are working around the clock to protect defences in 265 towns, according to Tibor Dobson of the Hungarian disaster management unit, but failed to stop more rivers breaking through dams at the weekend. Prime Minister Viktor Orban last week declared a state of emergency in eight of the country's 19 counties and on Saturday ordered an extra 7,000 people to guard its water defences. Interior Minister Sandor Pinter told the daily Magyar Nemzet that more floods were expected and further reinforcements were needed. More than 220,000 hectares of land -- one 20th of Hungary's arable land -- is under water with about 50,000 hectares of farmland destroyed, causing an estimated 300 million euros damage to the farm sector. 