What's going on with my shore line?

[paulspaddle]

There seems to be a subterranean water flow below our property.

It's hard to see how thick that ice is on the shore from the pics and not knowing the shore in the summer. The deck on the shore is typically 4 feet above the water, the ice is nearly level at the moment. It's squeezing through the boards on one corner.

You can see the build up of ice as the water flows onto the shore and lake then freezes.

The temperatures this weekend were -5 to -10 C and there was wet water on top of this ice.

What I think is odd is our property sits higher than the other properties in the bay, but this is only happening in front of us.

Its been an odd year with a high water table which may be a contributor to this.

Do you think there is reason to be concerned about this? Can a subterranean stream cause the shore to collapse? It's limestone and sand.

Thoughts/Opinions?

http://i913.photobucket.com/albums/ac331/paulspaddle/IMG_5259.jpg

 

[j_martin]

Re: What's going on with my shore line?

You have ground water coming out of the hill and flowing down onto the ice. It is the open end of a contained aquifer, the other end of which is at a higher place, and could be a hundred miles or more away.

It would be an artesian well or a spring if it was a specific spot. It's common to have water seeping out of a sandstone or limestone shore.

I have an elaborate system of drains under my house to deal with this sort of thing. The sump drains by gravity to a nearby water body, and sounds like a babbling brook in the basement sometimes.

In Wisconsin I've seen farm houses purposely built over such a seep, with a containing structure collecting it into a cistern for domestic water.

Hope it helps
John

 

[paulspaddle]

Re: What's going on with my shore line?

Thanks John, the idea of a natural cistern is interesting.

So seeing that doesn't fly a red flag that the ground above 'may' be at risk of caving into the lake?

My only other experience of subterranean water flow was under a church that engineers were very concerned about the integrity of the foundation.

 

[j_martin]

Re: What's going on with my shore line?

Thanks John, the idea of a natural cistern is interesting.

So seeing that doesn't fly a red flag that the ground above 'may' be at risk of caving into the lake?

My only other experience of subterranean water flow was under a church that engineers were very concerned about the integrity of the foundation.

Go down to the shore and look at the flowing water. If it is clear, you're in pretty good shape. If it's cloudy or muddy, it's removing material.

The material under my house is gumbo clay with gravel veins yielding water. Foundation is solid as a rock. Basement is dry as popcorn. The gravel veins are routed with small ditches and drain rock to the drain system, and then sealed off with plastic and concrete. The water, even though it is coming from clay, is crystal clear.

hope it helps
John

 

[4JawChuck]

Re: What's going on with my shore line?

The ice is moving and allowing water under it to flow on top, might be coming from shore...you have to go out and look where its coming from. It got real warm fast in the last week here in Manitoba, the ice is moving around on the lakes expanding and refreezing and thawing again.

We had a cottage on Lake Winnipeg when I was a kid and one year I went down to the lake in January and the ice had moved away from the shore about three feet leaving open water which was only frozen about 2 inches thick. It flooded out onto the ice pack about 50 feet which left me a perfect skating rink smooth as glass, never seen it happen again in 20 years.

Ice moves, I wouldn't worry about it.

 

[paulspaddle]

Re: What's going on with my shore line?

The water is clear.

The reason I mentioned the possibility of the shore collapsing is a cottage property about 300yards away collapsed into the lake. They don't know why this happened, but claim it's because their neighbour build a big crib dock and changed the wave pattern, thus erosion on their shore line. They also mentioned water flowing under the property as a contributor.

Chuck - the water is definitely coming from the ground although I can relate to what you are saying. I'm still getting to know this lake, but am amazed at how wind can create massive ice ridges and such.

In previous years the ice is usually too rough to skate on. Top layer of snow sticks to it and it has a pebbled surface. We walked out this weekend and kicked the snow away to find smooooth ice. Snow was loose packed and only 4" thick....easy to clear. Darn, didn't bring any skates!

 

[rbh]

Re: What's going on with my shore line?

With most springs, the water that pass to an outlet in a lake or a body of water (creek river etc) should have the gravels fully washed over from the out flow, look for the clean gravel, and you should feel the flow of the spring.
If you block it, it will find its way out were the nearest point of least resistance.
open it up and confine it to one area.

 

[4JawChuck]

Re: What's going on with my shore line?

I checked your pics and that water is clear, ground water would be heavily tinged yellow or brownish.

When it gets warm like it has been (1C today!) the ice at the shore line dislodges and the water underneath which is compressed by the ice squeezes out. If you have even been on the ice when you have drilled ice fishing holes you would see how warm weather pushes water out. I remember fishing on Tugby Lake many years ago and with 15 guys and three augers we drilled about 100 holes in the ice so we could move around. The next day it warmed up when I returned and the lake was flooded about 2 inches deep...no fishing that day unless you had rubber boots on.

Your neighbors having collapsed cottage footings is likely from poor construction not from underground springs. I have seen some really shoddy cottage construction over the years, one guy I knew just put his on 12X12X4 inch concrete pads on a pit of gravel which was 4" deep. His reasoning was the ground pressure of the cottage was so low and he had so many pads it would be OK.

It lasted 10 years before the whole thing started shifting around and he had to go back under and drill footings and pour concrete down 6 feet to get to solid rock to stabilize the place. He was an engineer too!