The watershed is the area of a land where the water will drain into a nearby body of water. If the area of land outside of your pond contains nutrients from fertilizers, manure, or goose droppings, these nutrients will be washed into the pond. The excess nutrients in the pond may cause algal blooms. If the source of the nutrients cannot be eliminated, the next best management plan is to plant nutrient absorbing plants in the watershed area and around the pond. Rushes, irises, and tall grasses have large root systems that can absorb the nutrients before they drain into the pond.