Enquiries need to be made as to whether potential development land floods from either fluvial water (ie. from the land), or from tidal water, rivers or other tributaries which are affected by sea level. Whilst development can be undertaken on sites which do have a flood risk element, this depends entirely upon the category of risk and potential mechanisms for escape and mitigation.
A simple rule is not to be put off initially by fairly randomly drawn maps obtainable on the Environment Agency’s website for any postcode as they are generally very widely drawn and are not always accurate.