Pond would be topped off by creek water as needed. Planning to install a bottom drain to pull down and exchange some water as required.

Our creek is in a major sand bed. After the initial pulse of a big rain passes, the creek water elevation is absolutely determined by the regional aquifer level. When the farmers fertilize in the watershed, I am pretty sure the first decent rain brings some of the excess fertilizers into the aquifer, and then shortly thereafter into the creek water. I do not pull any water during the application period for fall fertilizer.

This pond is surrounded by multi-species tallgrass prairie. The height variance across the field traps almost everything blown by the wind.

We do get the first hard frost around the end of October. The winter is then cold enough to ice over small ponds. Some of our plants die off and re-grow from new shoots the next year. Some of our plants go dormant and then re-grow in the same vascular system the next year.

If I left the "bay" as a hard clay bottom, I could probably bush hog it and then chain harrow the material out of the pond basin. That wouldn't work with 6" of top soil put back into the pond. That would be too soft to mow unless I let it bake in the summer.

The other option would be pull the water down a little in the early spring and just burn the dried out vegetation. I have experience performing patch burns on our prairie grass since it is a fire adapted system that grows better after a burn.

Contemplating a prescribed burn brings in another interesting option. How many nutrients remain in the ash? What happens when the ash goes into the main body of the pond after the water level goes back up? Would the escaping volatile gases during a burn remove some of the nutrients out of the pond basin eutrophic cycle?

My ground is generally flat. However, to the east is some very rolling terrain called the Flint Hills. The ranchers there do completely property burns every spring, frequently several thousand acres at a time. The draws between the hills contain lots of watershed ponds of varying sizes. The subsequent rains have to wash a lot of ash into the ponds. I rarely see those ponds as weed-choked marshes, so I assume the ash is not overly detrimental?

[Just throwing out more data if this becomes a longer discussion thread.]