Lake Erie (42.2° N, 81.2W) has a mean elevation of above sea level. It has a surface area of with a length of and breadth of at its widest points. It is the shallowest of the Great Lakes with an average depth of 10 fathoms 3 feet or and a maximum depth of Because Erie is the shallowest, it is also the warmest of the Great Lakes, and in 1999 this almost became a problem for two nuclear power plants which require cool lake water to keep their reactors cool. The warm summer of 1999 caused lake temperatures to come close to the limit necessary to keep the plants cool. Also because of its shallowness, it is the first to freeze in the winter. The shallowest section of Lake Erie is the western basin where depths average only ; as a result, "the slightest breeze can kick up lively waves," also known as seiches. The "waves build very quickly", according to other accounts. The region around the lake is known as the "thunderstorm capital of Canada" with "breathtaking" lightning displays. Sometimes fierce waves springing up unexpectedly have led to dramatic rescues; in one instance, a Cleveland resident trying to measure the dock near his house became trapped but was rescued by a fire department diver from Avon Lake, Ohio: