Europe is worried that the natural gas will not come back on again after Russia turns off the key line on Monday.
According to a Guardian translation, Robert Habeck said "everything is possible, everything can happen." The gas may flow more than before. Nothing comes in that case.
Habeck said it was a nightmare scenario and that Germany needed to prepare.
The rest of Europe is bracing for a permanent halt in Russian natural gas supplies after its scheduled maintenance from July 11 to July 21 Natural gas is transported from Russia to Germany and beyond on a yearly basis.
Bruno Le Maire, France's finance minister, told an economic conference in southern France on Sunday to prepare for a total-cut off of Russian gas.
Russian state gas giant Gazprom has cut gas flows to Germany via the Nord Stream 1 from last month due to equipment problems in Canada. Canada will waive the sanctions and return the repaired turbine in order to ensure continued gas flows in Europe, it was announced over the weekend.
Europe depends on Russia for 40% of its natural-gas needs from cooking in homes to firing power stations.
Fuel storage can be impacted by reduced gas flows into Europe. People are being urged to save energy.
Landlords in Germany are rationing water. The city of Cologne has turned off the street lights after 11pm, according to the Financial Times.
Taking shorter showers is suggested by Ha Beck. He said Germans shower for an average of 10 minutes a day. Five minutes is too long for me.
After Russia slowed supplies to the country, Germany moved into the second stage of its emergency gas plan. The country may start rationing natural gas in the last stage of the plan if the situation gets worse.
Industry would be the first to suffer supply cuts under the country's emergency plan. Business leaders and unions in Germany said that the move could cause job losses.
According to the top union official in Germany, industries are at risk of collapsing permanently because of the drop-off in Russian natural gas.