The study examined flood risk zones as ecological constraint to housing development and the response of residential property owners in the Calabar metropolis, Nigeria. Multi-research design was used to map flood risk zones. The continuous data types include satellite imageries, digital elevation model, distance to river and administrative boundary data made up secondary data. Primary data include questionnaires administered to 400 respondents based on the Taro Yamane sample size formula and multi criteria analysis was adopted to select flood prone zones. Findings revealed that places such as MCC road, Old Odukpani Road, Good luck Jonathan Bypass, IBB way, Murtala Mohammed way, Marian and Ndidem Iso Road are located at the very low risk zones. Furthermore, areas located within the Low-risk zone include: Atu street, Ediba Road, Palm street, Summit hills road, Uwanse road, Orok–orok streets, Mary Slessor avenue, 4th avenue and Barracks road. More so, streets such as: Eyo-Ita, Court road, Ekorinim, New Airport road, Atimbo, Bedwell street and Diamond road are located within the Moderate risk zone. Lastly, areas like Jebs road, Edem Ekpo street, Afokang street and Hawkins road fall under the low-risk zones, while no street was classified as very high-risk zone. However flash floods do a lot of damage to properties of urban residents yet many find it difficult to relocate due to cost implicatioin. 69.5% of respondents experience severe flooding 3 to 4 times a year while 10.5% and 20% experience the disaster twice and once respectively in a year. Majority of the respondents depend on government preventive measures. Mixed layouts varying from walled, unwalled to kindred has not help matters. Indication that Calabar is urbanizing rapidly with weak planning agency leading to irrationality of developers in land acquisition.