If you are working with a buyers agent, your agent should easily be able to identify the lots with 1% or 5% annual flooding chances.
If they cannot...
ouch. My confidence in their capabilities would be diminished.
The flood maps are included in WakeGov sites:
https://maps.raleighnc.gov/imaps/?pin=0744349643
You have to select Floodplains in the Environmental drop down.
Very little flooding is indicated in Riggsbee Farm.
You can also easily double check any address at NC Floodmaps.
https://flood.nc.gov/ncflood/
To be proactive, don't buy a home below the road where water can drain down the front yard and up against the foundation, or backing to a slope where the same can happen to the rear or side of the crawlspace. Make sure surface water flow is managed to avoid laying against the foundation.
Such will not show on official flood maps. It is just common sense.