Cases and solutions Environmental Geology 31 (3/4) June 1997 7 Q Springer-Verlag 231 Local engineering practices of erosion control in the coastal areas of the Niger Delta P. O. Youdeowei 7 T. K. S. Abam Abstract The paper reviews local engineering prac- tices of erosion control in the coastal areas of the Niger Delta, influenced by tidal activities, and ana- lyses the physical conditions and criteria for the application of control measures. The control meth- ods utilized include the use of sand-cement and sand-gravel bags, used rubber tire networks, wood- en groins, concrete retaining walls, sheet pile walls, and rock gabions. The effectiveness of typical cases of these measures are evaluated and suggestions made on improve- ments in design to ensure enhanced performance. Key words Erosion control 7 Coastal areas 7 Niger Delta Received: 22 February 1996 7 Accepted: 30 July 1996 P. O. Youdeowei (Y) 7 T. K. S. Abam Institute of Geosciences and Space Technology (IGST), Rivers State University of Science and Technology, P.M.B. 5080, Port Harcourt, Nigeria Introduction The area under review – the coastal region of the Niger Delta (Fig. 1) – is the outermost zone of the three hy- drometeorologic zones of the Niger Delta as defined by Teme (1988). The other two are the mangrove and fresh water zones (Fig. 2). This classification is based upon me- teorologic, hydrologic and vegetation factors. It is real- ized that even with the diverse and varied methods of erosion control and in some cases the use of inexpensive and ambient materials in the coastal zone of the Niger Delta, the effects of erosion remain unabated. Studies as revealed in this paper show that only a few of the protec- tive measures against erosion have as high as 50% effi- ciency. Included in this group are: used rubber tire net- work, rock gabions and concrete retaining walls. Others of even higher efficiency, such as concrete sheet piles, are imported technology and their high cost of implementa- tion has limited their application to only a few sites. It is certain that much more investigation needs to be Fig. 1 Map of Nigeria showing the Niger Delta Fig. 2 The major hydrometeorologic zones of the Niger Delta (modified after Teme 1988)