Excessive muck will very often hinder or completely plug fresh water springs in the base of the pond. This will often affect the water level of the pond, leaving some ponds several feet lower than where they should be. By cleaning the area of the pond that has the most spring activity, a good water level can again be achieved. And most importantly, the pond will again have a source of fresh water and added circulation. This is very important for certain types of fish as well as the overall health of the pond.
Organic sediment is very nutrient rich.
It can be compared to a extremely productive fertilizer. As this builds up, the perfect conditions are created for the overgrowth of plants. If the water is being treated with chemicals for plant or algae growth, removing the excessive muck will often reduce the amount of chemicals needed for control and make the treatments much more effective. Until recently, there were only two ways to solve the problem of a dirty or unsightly pond. The pond could be heavily treated with chemicals and additives to give it the appearance of a healthier looking pond.