The money, raised from council levys, will be handed over to the Environment Agency to protect those areas identified as being most 'at risk', but not covered by national plans.
Chairman of the regional committee Peter Ryder explained: "The local levy we have set enables us to identify and finance projects that will benefit local communities at risk of flooding, but which are not of the highest priority nationally. These are often small scale, but of huge significance to those at risk.
"Our region will benefit greatly from this funding, and I am most grateful for the support and commitment shown by our constituent local authorities, while recognising that demands on their resources are severely stretched."
Parts of London, Hertfordshire, Surrey, Oxfordshire, Berkshire, Essex, Buckinghamshire, Hampshire, Gloucestershire and Wiltshire will benefit from the fund.
Projects include flood alleviation schemes and improving small but critical watercourses, currently the responsibility has of the Environment Agency.
The Environment Agency's regional flood risk manager for Thames, David Murphy said: "This increase in local funds is very welcome. We will target this investment at local communities to reduce flood risk in innovative ways to fund actions to reduce the impact of floods.