Food Chain in a 100% Clay Pond
6 minutes ago
I dug some more test pits at our property this weekend.
One of the good low locations had nice sandy clay that was getting more clay-rich with depth. Certainly enough clay to seal a pond.
I then moved up to some higher ground where the "upper end" of a 1-acre pond would be located. After cutting about 10" of top soil, the location was 100% clay. I got down to max. depth of 8.5' for my mini-excavator, and was still digging in clay. The clay sides of my pit were smooth and polished and packed very hard.
Question for the experts:
If I finished a pond in that clay soil, I think it would be a very long time before any aquatic plants began to thrive in the pond. The pond will be sourced with pumped water from an adjacent groundwater pond, so there will essentially be zero surface water inputs of silt and nutrients.
Will this pond only grow FA, or be exceedingly low productivity?
Do I need to build some nice flats around the pond shores at a depth of 3' and re-cover those areas with 6-12" of top soil to get aquatic plants growing in the pond to aid all of the organisms at the very bottom of the food chain?
Any experience from managing a similar pond or just any advice would be greatly appreciated!