Various ways to deal with spoils and rebuilding or reshaping the pond basin. Initial goal I think would be to push out all accumulated sludge down to original pond basin and maybe excavate more depth to the downsized pond. The steeper the slopes (3:1 or 2.5:1) and deeper average depth the fewer weeds a pond tends to have. Keep in mind that steeper slopes mean more dirt needs to be removed thus more expense per acre of water. IMO a smaller easier to manage pond is a lot better to have and deal with than a large unmanageable, nuisance prone, poorly designed pond.
Spoils (removed sludge-muck) can be graded and vegetated so water runs away from the pond. Watershed drainage could be from specific areas that contain primarily water with low nutrient loads. A well rebuild smaller pond with optimum clay compaction and steep slopes with minimal seepage takes less water to keep it full due to low volume leakage compared to a seepage prone pond.
The local Soil and Water Conservation District engineer or regional soil scientist might be available for a site visit and a free opinion for your situation due to a desire to better manage the nutrients in the water shed. It is worth a phone call. If you explain your goals to a good pond builder he should provide several good options.
When water fertilization is part of the management, starting a pond as new and using fertilization to minimize nuisance plant growth is a lot easier, more predictable, more dependable due to more control of the overall nutrient budget. Duckweed, since it is a symptom of thick organic sediments and excess fertility, rarely grows in newer or even middle age ponds with 'average' nutrient loads. In an old pond with thick sludge and an unknown amount of nutrient inputs from internal recycling this makes it more difficult to manage or control the entire nutrient budget necessary for maintaining an optimum phytoplankton community so there is a dependable and consistent nutrient bloom to minimize the rooted weed and FA growth in large areas of shallow water. Ponds with deeper average depths, and lower nutrient loads rarely need fertilization to produce dense plankton blooms to manage for reduced FA and weeds.
Last edited by Bill Cody; 12/03/13 02:18 PM.
