Last client I worked with on pond design installed these as his watershed consisted of 100 acres of crops and during heavy rains it was very turbid runoff. Pond contractor installed 4 dikes across 50% of the creek width about 20 ft apart, so two on each side. I'm no engineer but the contractor was confident it would be sufficient. When consulting with your contractor see what he recommends in terms of the number and distance between them. I think 2-4 would be sufficient.

From your overhead it appears there exists another drainage down the tree line straight from a feedlot upstream. If that is another course of water I would consider something to slow that potentially high nutrient ag runoff water from entering pond directly...small berm with cattails create a wetland maybe to help slow water down and strip some nutrient levels before dumping into your pond.

Many men go fishing all of their lives without knowing that it is not fish they are after. ~ Henry David Thoreau

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