A straightforward explicit expression is derived for estimating the size and position of leaks in a water pipeline using the acoustic transient response. Experimental results are provided for a water pipeline with multiple leaks to demonstrate the usefulness and performance of the proposed approach. The form of the leak estimation expression can be further combined with an existing explicit expression derived for blockage detection. Using this combined expression it is also demonstrated that the proposed approach can detect and estimate leaks and blockages when they are simultaneously present in pipelines.