International Journal of Academic Engineering Research (IJAER) ISSN: 2000-001X Vol. 2 Issue 7, July – 2018, Pages: 14-19 www.ijeais.org/ijaer 14 Analysis and Design of a Residential Building against Flood Force in Floodplain Area: A Case Study of Ogbaru L.G.A of Anambra State, Nigeria. Nwajuaku Ijeoma Immaculata 1 , Ekenta Obi Emmanuel 2 1 Department of Civil Engineering, Nnamdi Azikiwe University, Awka, Nigeria, Email: nwajuafam@yahoo.com 2 Department of Civil Engineering, Nnamdi Azikiwe University,Awka, Nigeria, Email: ekentaobi@yahoo.com Abstract : Flooding, which has been a perennial problem in Ogbaru has caused much havocs and difficulties to the inhabitants of Ogbaru community, such as destruction of farmlands, destruction of buildings, lives and properties. The aim of this study is to minimize the harm caused by flooding through design of flood proofed residential building against flood force. A proposed residential building was designed against buoyance force and the result obtained showed that the dead load (structure weight) (2524.573KN) from the house is sufficient to prevent overturning from the buoyancy force (2499.33KN). The marginal difference between the two forces is not much. Therefore, dry flood-proofing should be limited in areas where flood velocities adjacent to buildings is greater than 1.524m per second during the design flood. It should also be noted that in as much as buoyance force will equalize hydrostatic pressures on the foundation walls, hydrodynamic and flood-borne debris impact forces will still apply. Keywords- Flooding, Dry flood-proofing, Buoyance force, Dead load, Flood velocity 1. INTRODUCTION 1.1 Background of the Study Flood plain is the residual area outside of the floodway where the water velocities are less and flood protection and flood-proofing measures can be considered. In practical terms, the chance of flooding can never be eliminated entirely. However, the consequences of flooding can be mitigated by development of flood plain. Certain factor such as the effects of climate change cannot be brought under control. However, suitable actions are both possible and needed to begin to reduce the exposure and vulnerability to flood hazard of people and property and, thereby, enhance flood security. (De wrachien et al., 2010). In Nigeria, Anambra State was tagged flood disaster zone. The National Emergency Management Agency (NEMA), (2012) reported that the 2012 flood in Nigeria was declared a national disaster as it affected over 2.3 million people and killed over 363 people. Some Nigerian cities were swept off by the flood and affected 34 out of 36 states of the federation including Anambra state which was ranked as the worst hit. According to NEMA (2012), at least 68 people were killed in Plateau State in central Nigeria and also 25 bodies found in Benue River after the flood while properties were also lost. These occurrences show that flooding is affecting the national populace and economy; yet mitigation measures are still poor as affirmed by Anambra State Ministry of Environment (ANSEMA) (Efobi and Anierobi 2013). Anambra State is situated at the lowest point of the River Niger and as such is flood prone. These periodic flooding that occur on rivers, form a surrounding region known as flood plain and it is on this plain that economic activities of these people take place. This was the reason why Anambra State was greatly and badly affected by flood (Sun News,2012). The affected local government areas were Anambra West, Anyamelum, Anambra East and Ogbaru. These local governments were highly submerged in water. The impacts of such floods have been severe due to the number of human populations exposed following the attractions of coastal areas for economic and social reasons. The most effective flood mitigation method is relocation but when this method is not feasible or cost-effective, flood- proofing may be an appropriate alternative. Flood-proofing techniques usually require either dry measures or wet-flood techniques to secure thorough protection. 1.2 Aim and objectives The aim of this study is to design residential buildings against flood force in Ogbaru L.G.A. This will be achieved through the following objectives: i. To identify the causes of floods in Ogbaru Local Governmemt Area in 2012. ii. To compare dead load of a proposed building with buoyance force to prevent overturning of the building 2. LITERATURE REVIEW Ogbaru community suffered most of the floods on account of their relatively low and flat disposition with slope angles of