ABSTRACT
What is implicit in the state of Lake Michigan-Huron water levels is not only the steep decline in levels since 1997, but also the narrowing of the water level difference between Lake Michigan-Huron and Lake Erie (also known as the head difference). To make a meaningful interpretation of the change in the head difference since the dredging in 1962, the Study used the entire water level data series from 1860 to 2006. Finally, the Study sought to explain the decrease in head difference between Lake Michigan-Huron and Lake Erie of 23 cm observed since 1962 and estimated from linear trend (IUGLS 2009).
