This paper describes the development of Pandle's model for assessing the preliminary performance of tidal schemes in semi-diurnal situation to cope with cases in which the diurnal variation may be significant. This is often the case in many regions in Asia. The approach uses harmonic analysis, to cope with the two cases of one- and both-way generation. The program is designed to requires only modest computational resources. For demonstration, the procedure is applied to a case study involving the urgently needed second link for road traffic between Singapore and Jahore.