Larson et al. (1987) proposed a closed-form solution to describe the development of river delta coastlines owing to sediment supply from the river. This solution is for a beach of infinite extent adjacent to the river mouth. However, in reality, the beach length is always finite due to the existence of man-made structures or headlands. It is, therefore, useful to derive a new analytical solution to gain a better understanding of beach behavior under the effect of boundaries.