After spending thousands of dollars to clean out his pond, Homer Daniel wanted to be sure to keep the water clean. So to prevent sedimentation, he planted grass buffer strips around the 3-acre gem near Wake Forest, N.C. And he's created a small wetland to filter sediment and nutrients out of water entering the pond.
The runoff water from Daniel's fields flows through grassed waterways into his wetland. A catch basin in the 20- x 20-foot area is formed by a small dike with a Hickenbottom drain. The runoff water passes through a gravel filter before entering the pond.
"I can see the difference. The water in my pond is much clearer," says Daniel.
Bullrushes, sedges and dogwood trees were planted in the wetland to absorb the trapped nutrients. Cattails and other native species quickly found a home.
"Native plants are as good as or better than those we planted," says Tom Hill of the Wake County Soil and Water Conservation District. As urban developments spread into rural areas, he receives many calls from pond owners who have problems with excess nutrients and sediment.
Construction of a small wetland area like this costs around $1,800. But because Daniel's pond is in a targeted watershed of the Neuse River, a clean-water grant helped pay for his wetland.
By using conservation practices, Daniel has reduced soil loss on his farmland to 3 tons per acre. But even with required erosion-control measures, construction zones can lose 40 to 80 tons of soil per acre, notes Hill.
"We see ponds turn red with suspended clay.
A constructed wetland is often one of our recommendations," says Hill.
"I would absolutely recommend a wetland area for new ponds in urbanizing areas."