The high waters of the "flood of the century" along the Oder River between Poland and Germany have largely receded, but the long-term questions about how best to "manage" the river remain open.
Scientists point to developments in computer modeling that should provide better data to help head off trouble the next time.
International cooperation got a boost from the flood, too. Polish Interior Minister Leszek Miller met with German Construction Minister Klaus Tpfer and Czech Deputy Prime Minister Jiri Skalicki last week to agree on short-term practical flood prevention measures.
Environmentalists are calling for a rethinking of river management. The German group BUND has called on the German government to drop its plans to "canalize" several rivers - straightening them out to turn them into watery Autobahns - and to lobby the Czech Republic and Poland to hold back on further canalization of the Oder and the Elbe Rivers.
In a recent press conference in Berlin, Ernst Paul Drfler, a BUND expert on waterways, also said, "In the future, riverbanks have to be off limits for housing."
Some environmentalists have gone so far as to suggest that residents of the Oderbruch region - under threat for weeks but never completely flooded - move elsewhere. The area is filled land, a project carried out some 250 years ago under Frederick the Great, whose engineers redirected the Oder to turn marshes into farmland.
Not surprisingly, the evacuation solution has not proved popular. But Florian Engels, spokesman for the Environment Ministry of the state of Brandenburg, agrees with the activists, saying, "We need more flood-plain acreage to give the river someplace to go." His ministry is planning to add more than 5,500 acres to the nearly 12,500 acres already available to absorb floods. The new territory is mostly farmland, with only a few inhabitants who will have to move.
Across Germany and other countries, canalizing has been blamed for the "100-year floods" that the Rhine seems to be experiencing about every other year. The Oder, though somewhat canalized, is closer to its natural state than many European rivers.
But canalization is only one of the causes of this summer's floods, one of the worst natural disasters on record in Central Europe, with a death toll of about 100 people. Deforestation, especially in Poland and the Czech Republic, is the other big cause.
Woodlands act as a sponge to absorb rainfalls. But, says BUND official Michael Weidlich in Berlin, "the forests there are sick, or already destroyed, because of industrial pollution."
The technical side of flood prevention is well understood, according to Heinz Gnther, a scientist at the government-funded Geesthacht Research Center in Geesthacht, Germany. Computer models use data about rainfall to produce scenarios that suggest where water is likely to collect and how long it is likely to stay there. Officials can use the models to estimate how long a dike will have to hold, for instance.
Although some areas along the Oder are still being pumped out, the emergency appears to be over. The sandbaggers that a few weeks ago were working around the clock have been succeeded by civil servants and insurance-company employees punching away at calculators to estimate the damages. Figures are expected in by the end of the month.
"There have been estimates of a billion [deutsche marks, $550 million] in damages, but those have been just guesses," says Carola Frohberg, a spokeswoman in the Interior Ministry of the German state of Brandenburg.
The German soldiers and the police units who sandbagged around the clock and kept dikes from breaking have been thanked by grateful villagers at special celebrations and church services.
"The soldiers' work paid off. The situation would have looked very different without them," Ms. Frohberg says. The flood of river water has given way to a flood of charitable contributions as officials try to sort out who should get what aid.
Poles could take comfort in some successes, too, such as the saving of the historic city center of Wroclaw and the city's zoo and its animals. Volunteers turned out in force in response to a televised appeal for sandbagging help.