The 52-year-old woman drowned after severe rains hit the central Prahova region of the country, the environment ministry said.
A 61-year-old man from Dambovita, who was swept away on Saturday, remains missing, it added.
A thousand homes and more than 3,000 outbuildings were damaged, while 90 bridges and 35 kilometres (22 miles) of roads were also hit in the flooding.
Transport Minister Gheorghe Dobre said Romania hoped to secure a 60 million euro (77 million dollar) loan from the Council of Europe Development Bank for infrastructure repairs.
Nearly 800 heads of cattle were killed in the flooding, which also swamped farmland and forests.
It was the second time the country has been hit by flash floods in two weeks. In late April severe flooding affected about 140 towns in northern and western Romania, causing damage estimated at 20 million euros in the western Timis region alone.