November 7th, 2012
Using Geography to Your Advantageby Steve Rowswell January 10, 2013
Before you ever fish a lake, it’s good practice to look at satellite images of the lake, as well as topographic maps and depth charts. Using these maps together will give you a good idea of the geography of the land surrounding the lake as well as the lake itself before you get there, allowing you to save time while you’re on the water.
Here in Ontario, many of our lakes are surrounded by tall, dense trees. Generally, unless trees are in the water and providing structure for a fish, you don’t think of them as having any impact on your fishing. However, when the sun is low in the sky, especially at sunrise, trees will cast a shadow over the water, giving fish the perception of low light conditions. For fishing a topwater, this can prolong the window of opportunity when the technique is effective. Since the sun rises in the east, the morning shadows will be on the east side of the lake. Conversely, as the sun goes down, the shadows will be coming off the western shoreline. Using satellite imagery, such as Google Earth will allow you to pinpoint shorelines home to the biggest trees.
The east and west sides of lake also tend to vary in types of structure and bottom composition. Prevailing winds come from the west therefore more often than not, the west side of a lake will be the calm one. The impact of the wind will be more evident on larger bowl shaped lakes than small or narrow ones. As you probably know, when the wind is strong enough, the current it creates will stir up sediments on the bottom. Over thousands of years, these prevailing wind patterns and water currents have changed the landscape of the bottom. I’ve found that to the west, you’ll generally find a sandier bottom since the wind isn’t stirring it up as frequently, as well as lily pads, which generally don’t do so well in the waves. The eastern side of a lake generally has a rockier bottom with sparse patches of submerged vegetation as sand and sediment has been washed away over the years.
The same sort of pattern can be used for mid lake islands too. The west side of an island is exposed to the westerly winds and usually exhibits the characteristics found on the east side of a lake. Contrarily, the east side of an island will then be the lee side and show characteristics of the western part of the lake. This theory doesn’t hold true for all lakes, but is a general pattern I’ve found fishing in southern Ontario. Depending on the type of structure you’re looking to fish, this will allow you to find similar structure in various locations, and begin to run a pattern.
A topographic map can also help determine where rainwater will naturally run off into a lake. Depending on the circumstance, water run-off can be good or bad. If the lake is near a city, the run-off from that area will most likely be contaminated with fertilizer and other nasty chemicals, making that spot a virtual dead zone. On the other hand, non-polluted run-off can be a source of warmer, more fertile water and create a sweet spot along a bank.
Every day on the water it’s you against the fish. It’ss cliché, but an NFL coach doesn’t go into a game without watching tape of the opposing team, and you shouldn’t go to a lake without studying where the fish live. Good luck and tight lines!
About AuthorMore info about author
Steve is a talented multi-species tournament angler, based in Orillia Ontario. When Steve isn't on the water, writing articles or editing YouTube fishing videos, he's an Environmental Studies student at Carleton University in Ottawa, Ontario. Steve plans to pursue a career following his passion for the outdoors and in particular fishing.More by Steve Rowswell