When the central basin of Lake Erie begins to warm and the water temperature reaches the mid-50's, low-60's, the walleye begin to group up in wide spread schools along the 50-60 feet depth of water. Normally, on any lake or reservoir as the water temperature warms the bigger fish move to deeper, more comfortable water. Lake Erie is a prime example of this. Easy accesses to colder water and bait fish such as smelts and alewives ( high protein forage fish found in cooler water) make it simple to understand why trophy walleye find their home in the waters off Erie, Pa.