When I built the sediment pond the main purpose was to filter out sediment before it reached the main pond. A secondary purpose was as a forage/grow out pond.
One thing I had not anticipated was for the sediment pond to catch tannin from the farm field and keep part of it out of the main pond. We had a wheat crop in the adjacent field. It was no-till planted to double crop soybeans. We have had a very wet season. The first planting of beans did not come up because of heavy rains. This rain stood in the field for a while in the ridges made by the planter in the bottom of the terrace. Then another rain came along. The first rain had stood in with the wheat stubble long enough to create a brown tannin stained water. The second rain washed it into the pre-sediment pond and then into the sediment pond. A little reached the main pond but not much. The tiny pre-sediment pond is a very brown stained water and the sediment pond less so but still a very noticeable stain.
We had put some blue and also white tilapia in both the pre-sediment and sediment ponds to grow out. They seem to be doing fine in both ponds along with the other fish. But the water sure is stained looking. I put some crushed limestone which has a significant amount of ag lime in it along one bank to help neutralize some of the acid content, which is shown in the picture.
