Pond Boss Forums POND CONSTRUCTION Soil questions digging pond in sand

hi there brand new to this site. have new build home built in old quarry,100% sand. 2 acres back during the construction process i noticed about 30 yds by 70 yrds of low standing water ,always there for the whole year,maybe 4 inches deep. looking around i noticed several other "pond opurtunities like this one". long story short the house and the 5 acres are built in this "bowl",the old quarry,probably 30 ' lower than everything around us. an escavater dug the pond at this spot 2-9 feet deep and about 1/3 acre. there is no run off available because the sides and lot are all sand,,i mean like a beach sand. the builder said that the pond is being kept fill by the actual water table/aquafier area,being literally below sea level situation. my question is i love my little pond and look forward to dressing it up,but it seems like with the big snow melt,the sides seemed to roll in on itself a little. the builder told me the water pressure when its filled would hold sides up. i need help holding sides up in sand. will the vegetation on shore help hold it up,or will this always happen? maybe digg it wider,more gradual? remember the only way to gain depth is to dig deeper being all sand,no runoff over spring/water table. thanks

Welcome to the forum Mahindra!!!

One thing about groundwater ponds is that the level always fluctuates with the water table level...also, the sides will have zero water pressure holding them up. The water level is the same in the sand as it is in the open area. In sand like yours, the only way to keep a shape is to have a gentle grade as steeper sides will always collapse without vegetation or something holding it in place..sand can't be compacted. You could possibly truck in some soil to mix with the sand to get plants established and to bind the sand together into something more solid.

Groundwater ponds can be great, but do require some different management issues than sealed ponds, such as nutrients and water flow through the pond continuously rather than being trapped.

A couple pond owners here, esshup and Dwight have groundwater ponds. Both have a lot of history managing them well....Dwight's pond is also a quarry, but gravel IIRC.

What I've learned is to dig the pond deeper than what you'd think because you are at the mercy of the groundwater level. No way to stabilize the banks because of the fluctuating water levels from low to high.

I'd make the banks above the low water level no steeper than 4:1 and in the water belos the low water line no steeper than 3:1. My pond, since renovated in 2008 has fluctuated almost 80" in depth. At the low water level, I still have 11' of water in the deepest part.

Around here, sand will always seem to squirm out of any dirt mixed with it. You can use vegitation above the high water line to hold it in place, but I haven't found anything to use on or in the sandy area that is between high and low water levels. The water level fluctuates too much for anything to grow for any length of time.

Hello Mahindre-------

Welcome aboard. You are really going to love this place, the people are the best on the planet. The information you get is as good as the people.
What I say is just about what you have already heard. The water will not hold the sand in place or at least I have never seen that to be the case. The gentler the sloop the better off you will be. If you can get anything to grow it will help that will be the best way to hold the sand in place. There are some erosion blankets that have really been a live saver for us on places that wash or erode easily. They are easy to roll out do not cost much, they hold the dirt in place until the grass takes hold. With no runoff once the grass gets going maybe the problem will be solved.
As stated before the water will go up and down with the weather conditions that are the nature of the ground water pond, not bad or good just the way

THANKS, I WILL WORK ON IT,MAYBE OPEN THE SIDES UP SO ITS MORE GRADUAL.