Computer models that simulate the climate suggest that, as a result of warming, extremely wet winters could become up to five times more likely over the next 100 years, with more intense downpours in the winter months driving a greater risk of flash floods and river flooding, alongside risks from sea-level rise. Extreme flood events such as those in the summer of 2007 could become more frequent and severe, putting homes, businesses and infrastructure at greater risk. The government estimates that annual damages from flooding alone could increase to between £2bn and £12bn by the 2080s, an increase of about two to 10 times compared with current-day estimates. Critical infrastructure, including water-pumping stations, water treatment works, transport and electricity systems, and schools and hospitals sited in flood-risk areas could also be threatened, while heavy rainfall events could increase the risk of water contamination should sewers overflow. Current government estimates suggest about 330,000 properties are currently at risk of flooding, and climate change could increase this to between 630,000 and 1.2m by the 2080s.