By Matthew Phillips, Aquatic Biologist and Environmental Scientist
I remember a few years ago when I first stepped foot onto a frozen lake. Having lived my entire life in the south, a frozen body of water may as well have been a mythological creature, but there I found myself, on the edge of an 11 square mile frozen lake. My friends all assured me that it was OK as they effortlessly walked across the ice, but I was still cautious, even as I gazed into the distance and saw cars driving on the ice. I finally did proceed, one baby step at a time, followed by a complete wipeout, much to the enjoyment of my friends. As the winter and following years progressed, I became quite accustomed to not only walking on the ice, but also driving my truck out on it. It took some time, but I was able to “read” the ice and determine when it was safe to walk on.
That all took place in Northern Minnesota, where learning to walk on ice comes right after learning to walk and right before learning to ride a bike. While in Minnesota, I was taught the various thicknesses of ice and what it could and could not support. I was also taught to look at the color and shape of the cracks, know the depth of the water underneath the ice, remember the previous week’s weather temperatures and precipitation, and observe animal activity, undesired water current and flow underneath the ice. All of these factors, and many more, determine the overall thickness of ice and how safe or unsafe it might be. As you can imagine, ice changes constantly. What was safe to walk on one day is unsafe the next and just because it is safe on one lake, doesn’t mean that it is safe on all lakes. Here in the Mid-Atlantic States, things are very different when it comes to ice on ponds.
In most of our service areas, iced-over ponds can be unsafe for the simple fact that it does not get cold enough or stay cold enough for sufficient ice to form. Other factors can lead to unsafe ice. Most of the ponds in our area are for stormwater retention purposes and are very susceptible to heavy flows. While there might be ice on a pond, a little bit of rain or even snow can weaken the ice. The runoff also will contain salts and sand from the road treatments that will weaken the ice once it is in your pond. Also, many ponds have fountains or submerged aeration systems which cause movement along the surface of the water. This can cause weakened or very thin ice. However, as mentioned, it does not get cold or stay cold long enough in the Mid-Atlantic States for safe ice to form.
Be safe as the colder weather approaches and remember to stay off the ice no matter how thick you think it is. There can be several hidden weak areas that will instantly break sending you down. I should know. While in Minnesota, I foolishly walked too close to a muskrat house and in an instant, down I went. I was extremely fortunate that I was only in waist deep water and we were near my truck so I was able to warm up, but it was an experience I never want to repeat or see happen to anybody else.