Searches on house we're buying show significant risk of surface water flooding.

[paddingtonbear1]

We weren't expecting any kind of flood risk... not sure what to make of it. The report says that the site and area surrounding (up to 25 m) would be expected to be affected by surface water flooding in a 1 in 75 year rainfall event to a depth of between 0.3m to 1m.
The property is fairly high up and not near any river etc.
Anyone else had this? What did you do? We've asked for a further report and need to check the insurance. Our surveyor also found an unexplained high damp meter reading from the floor under the stairs, dh is hoping there is no connection!

It's worth considering what's above the house in height. My parents' house is on the side of a mountain so unlikely to be flooded by water rising except in a biblical flood situation. When they built the house they put in a run-off channel around the uphill side of the house and all entries have a step up of around 5 inches. In very heavy rain they get a flash flood which has never entered the house, but definitely would have if not for the step up at all the doors. They also had to put a bump along the gate entrance where their gateway meets the road to stop rainwater coming off the road and down the driveway as it was bringing loads of silt with it.

Don't know why that posted twice, but as User1497etc posted above, a medium/high risk of flooding is significant. Insurance companies use the 1 in 75 year event, but the EA uses a different classification - high is a greater or equal to 1 in 30 chance in any year, medium is less than 1 in 30 but greater than 1 in 100 chance in a year.

Personally, I would be double checking the flood risk data.

Sorry - ignore last post, was mixing up the RoFRaS rating with the pluvial ratings

As you were ...

According to them there is not a problem; we have supplied photos and videos of the water flowing out of the storm drain into the road and so on but still they do nothing

is it entering properties or threatening properties?

Have you looked at the environment agency flood map? That will give you more data. It's not just assessed on proximity to rivers, the water flow is modelled. There are some ways you can protect your ppty against flooding. Individual property protection, removable door barriers, higher thresholds, barriers to block toilets and prevent sewer backflow. Or you could build a flood wall around it, that obviously would need to be factored into the asking price.

With climate change and increased building meaning less places for water to drain to, flooding is only going to increase, so I would not ignore it.

Not a helpful addition to the thread but possibly amusing. We lived on the side of a hill and our house succumbed to flash flooding coming down from a common about 1/2 mile away. It came down the road and into our kitchen - the road was about 8 inches higher than our driveway. We talked to the council to see if they could do anything and the surveyor's first comment was that it was "because your house is lower than the road" - well yes, but since the house was over 300 years old we didn't feel that was actually our fault. In the end we managed to get them to resurface the road sloping away from the house towards a drainage ditch - problem solved but it took 2 years for them to agree.