Pond Boss Forums INTRO Questions & Observations Open Water in Minnesota

I have 10 to 12 inches of ice on my 5 acre pond. The exception is in the North Bay on the north and west sides, where open water extends out from 8 inches to 24 inches from the bank. The total lineal distance of open water is 240 feet as determined by my GPS measurements.

Our temperatures here in southwest Minnesota have been in the high teens and twenties at night and up to thirty –thirty five degrees for a few hours during the day for the last few weeks. Also, it has been mostly cloudy and overcast for the same period.

Is this a case of localized intense global warming? Do I have a volcanic activity heating the water from below? Am I the victim of nocturnal pirates utilizing bank heaters to intimidate me?

Any real thoughts on the cause would be acceptable too!

Thanks - Dwight

My experience and what I know from my icefishing friends says that the ice is (almost) always thinnest at the banks and starts melting from them too.

In the absence of any solar influence during the melting period there are still several variables I can think of which would cause one side of the pond to have open water. The one I think most likely is wind direction and/or wind breaks causing uneven freezing when the ice formed (it was thinner there) or uneven melting (the 35 degree daytime winds strike the North bay). But there may be lots of better reasons.

Most ponds tend to thaw from the north first. The reason for this is the sun sits farther to thwe south in the winter causing it to warm the north banks first.

I should have mentioned that other ponds and lakes in the area don't have any open areas unless they are aerated.

I agree with Theo Gallus and h20fwlkillr that lakes and ponds usually thaw first from the north and near the shoreline. Also, the wind can significantly affect the thaw in an unprotected body of water.

I think there may be another reason. After all, this is Minnesota! A pond or lake thawing to open water generally doesn’t have a prayer of happening until at least mid-March.

The earliest I have ever had a boat on the water in southern Minnesota was on February 28, 1987. How I remember that date is a story worthy of a campfire!

Dwight

Dwight, The open area may be due to groundwater discharge to the pond. Would that side be hydraulically upgradient?

My gravel pit style ponds always open from the southwest. Groundwater flow at my place is from SW to NE, so this is the discharge point of relatively warm groundwater. If your pond is clay lined you can toss this theory on the scrap heap.

Here in Michigan my ponds are all completely open. There is no frost in the ground. I'm actually planting trees this weekend, unprecendented at least for me in mid-January.

Steve - I feel like Colonel Clink, I know nothing!

How would you determine which side is hydraulically upgradient?

What I know is that the Rock River is east of the pond (300-400 feet east of the east pond shoreline) and the river flows south. When the pond was being excavated it was connected to this river by a channel that was dug by the Ready-Mix company that was harvesting the gravel. The channel was open from late spring to late fall and then closed during the winter. The next year in the late spring when they re-opened the channel the water level in the pond would drop 12-20” over a day or two time frame.

Your further input is greatly appreciated!

Michigan is one of our favorite states to visit. Do you suppose you have no frost in the ground because or your proximity to Lake Michigan (other than a mild winter).

We are located a maximum of 100 miles north of you and even with the mild winter (so far), we have frost down several feet.

Thanks - Dwight

Dwight,

The actual way to determine gradient would be to have three wells set in that saturated gravel layer and survey the elevation of the water level in each well. Three points define a plane (the groundwater surface)with a slope in one direction.

You can ballpark it by knowing that the Rock River is draining your property, therefore the predominant flow should be toward the river (east)with a downstream trend (eastsoutheast). Topography also has an influence because it creates head differences. If you have any high (or low) areas nearby, they may deflect flows from the expected direction. The north and west sides opening first is consistent with drainage to the southeast since upgradient is northwest. Remember that groundwater temperatures are near 50 degrees F and will definitely melt ice if there is good flow. The north side also has southern exposure and warms quickly so there may be two things working here.

We have been above 40 since Christmas. My property is low so has received quite a bit of runoff and groundwater recharge (pond levels are 4-feet higher than September and still rising). The Lake definitely moderates our climate, the thin strip along Lake Michgan is listed as USDA Zone 6b (-5F) which is equivalent to Kentucky.

We had frost in late November and early December but never had good ice due to the groundwater discharge. Water has been slowly seeping onto the edges of the ice for three months.

Another good explanation/translation from Hydrogeologist into layman's terms. Thanks, Steve.

Steve - Somehow, that all makes sense to me!

You have a real gift for translating your technical knowledge into terms that can be understood by someone like me with no knowledge of Hydrology (other than water flows down hill).

The nocturnal bank heater intimidation theory was fun, but……..

Do your ponds freeze over enough for ice fishing?

Most Januarys around here we think nothing of driving across a lake to get to our ice fishing spots.

Thanks - Dwight

Seriously, I think there should be a thread that we cut and paste all of Steve's posts. I spent dozens of hours in University lecture rooms and couldn't get an instructor to explain things that well. Nicely done, again.

Aw shucks guys stop it , just trying to pay this site back for all the valuable information on pond management I've gained and will continue to benefit from in the future. This is truly a great community. It's nice to be able to add a tidbit or two from time to time.

Dwight, we've had up to 9-inches of ice in the past. This is just a strange winter. Since we are only getting started with stocking, I haven't pulled any fish through the ice yet.

I was gonna go with nocturnal pirates... :rolleyes: