The main river coursing through Thailand's capital swelled to record highs Friday, briefly flooding riverside buildings and an ornate royal complex at high tide amid fears that flood defences could break and swamp the heart of the city.

Ankle-high water from the Chao Phraya River spilled through one sandbagged entranceway of Bangkok's treasured Grand Palace, which once housed the kingdom's monarchy. The army was pumping out the water, and tourists were still entering the white-walled compound.

The river has filled roads outside the palace gates for days, but the water has receded with the tides, leaving streets dry again.

But the higher than normal tides in the Gulf of Thailand, expected to peak Saturday, are obstructing the flood run-off from the north, and there are fears that the overflows could swamp parts of downtown. The government also is worried major barriers and dikes could break.


People carry their boat into a business building in flooded central Bangkok on Thursday. ((Damir Sagol/Reuters))

Friday's morning high tide passed without a major breach, but the waters briefly touched riverside areas closer to the city's central businesses districts of Silom and Sathorn.

"It is clear that although the high tides haven't reached 2.5 metres, it was high enough to prolong the suffering of those living outside of the flood walls and to threaten those living behind deteriorating walls," Bangkok Gov. Sukhumbhand Paribatra said.

The flood walls protecting much of the inner city are 2.5 metres, and Saturday's high tide is expected to reach 2.6 metres.

Seven of Bangkok's 50 districts — all in the northern outskirts — are heavily flooded, and residents have fled aboard bamboo rafts and army trucks and by wading in waist-deep water. Another eight districts have seen less serious flooding.

Fresh flooding was reported Friday in the city's southeast when a canal overflowed in a neighbourhood on the outer parts of Sukhumvit Road.

Many small streets have been turned into canals as water from the already flooded north pours into the city, CBC's Catherine Mercier said from Bangkok.

"This is not a tsunami-like event or an earthquake where everything happens overnight — it's been a slowly evolving situation," Mercier said Friday. "Authorities say it's making it even more dangerous because people are ignoring orders to evacuate."

International charity Save the Children said it was concerned that crocodiles and snakes were lurking in stagnant floodwaters it said are growing filthier by the day.

"Every day we see children playing in the water, bathing or wading through it trying to make their way to dry ground," said Annie Bodmer-Roy, the group's spokeswoman in Thailand.

The aid group said many families have been left without access to running water or clean toilets.  

"There is a very real risk of waterborne or communicable diseases such as diarrhea and skin infections taking hold if families can't maintain basic standards of hygiene," Bodmer-Roy said. "It is essential that the risks facing children in this crisis are understood and steps taken to keep them safe."

The floods, the heaviest in Thailand in more than half a century, have drenched a third of the country's provinces, killed close to 400 people and displaced more than 110,000 others. The water has crept from the central plains south toward the Gulf of Thailand, but Bangkok is in the way. It is literally surrounded by behemoth pools of water flowing around and through the city via a complex network of canals and rivers.


Thai residents walk through floodwaters as they evacuate their neighbourhood next to the Chao Praya river in Bangkok on Friday. (Nicolas Asfouri/AFP/Getty Images) )

Economic analysts say the floods have cut Thailand's 2011 GDP projections by as much as two percentage points. Damage estimates of approximately $6 billion could double if floods swamp Bangkok.

Most of Bangkok, however, has remained dry and most of its more than nine million residents were staying put to protect their homes.

Still, fears the inner city could flood has fuelled an exodus, as Thais and expatriates alike sought refuge outside Bangkok and foreign governments urged their citizens to avoid unessential travel to the threatened city.

Officials were also making emergency preparations, setting up shelters on high ground and outside Bangkok.

Dr. Nguyen Viet Hung said the Bangkok Medical Centre has been preparing for weeks, readying staff and supplies for the rising water.

"We have set up a war room as a command centre and we are actively involved in providing relief to the victims and receiving referrals from affected hospitals," an emailed statement said.

The U.S. State Department cautioned against all but essential travel to areas of Thailand affected by the flooding, including Bangkok, because of transportation difficulties and shortages of certain food items.

Canada's Department of Foreign Affairs is advising against "non-essential travel to Bangkok and flood-affected areas." The advisory doesn't extend to Suvarnabhumi International Airport, a busy international travel hub that is still operating.

On Thursday, an emotional Prime Minister Yingluck Shinawatra acknowledged her government could not control the deluge.

"What we're doing today is resisting the force of nature," Yingluck told reporters. She said the water bearing down on Bangkok was so massive that "we cannot resist all of it."

Flooding has closed Bangkok's Don Muang airport, mainly used for domestic flights, but Thailand's main international airport is operating as usual.

The government's Flood Relief Operations Centre says its contingency plan involves the Thai military and government agencies transporting people from evacuation points in the capital to outlying provinces.

With files from CBC News