Use native plants to protect our treasured streams

by Beverly Hunter, Spring 2003

You probably have one of Rappahannock's treasures on or near your land—a stream, river, or pond. How can we protect them? Here are some pointers.

First, take a walk to your favorite stream. Observe the vegetation on either side of it. Is it crops, lawn, pasture, or forest? Are the banks of the stream bare or covered with grass, shrub, or trees? Is erosion on the banks low, moderate, or severe? These pictures provide examples of different vegetative buffers, slopes, bank covers, and erosion.


Steep, eroded left bank of this stream contrasts with the vegetation-covered right bank. A buffer of trees and shrubs protects the steep right bank, while mowed pasture on the left bank allows rapid runoff and erosion, depositing sediments here and downstream.		Severe erosion results from having no vegetative buffer or bank cover. The soil around the stream was disturbed by bulldozers, no erosion controls were established, and sedimentation has washed into the stream.

Mowed lawn to the edge of the stream causes rapid runoff during rainstorms. This results in erosion and flooding, reduces replenishment of groundwater, and provides no cooling effect for the water in summer. Sedimentation from runoff flows into the pond, reducing the fish and other aquatic life.

Native trees and shrubs provide a natural buffer on the steep hillside and banks of this stream.
Photos courtesy Beverly Hunter.

Which of these four examples is most like your stream? Under natural conditions, buffers extend along creeks, streams, and rivers, providing a network of vegetation vital to the terrestrial and aquatic ecosystems. Plant stems absorb the erosive force of flowing water and wave action, while roots hold soil in place. These vegetative buffers

Trap and modify soil sediment and chemicals, including nitrates, phosphates, herbicides, and pesticides before these pollutants can enter streams.
Stabilize stream banks by reducing bank erosion and by slowing stream meandering across pasture, lawns, and row crop fields.
Increase water-holding capacity of soil, which moderates flooding and recharges groundwater.
Filter sediment carried from construction sites, freshly tilled gardens and crop fields, dirt roads, and other earth-disturbing activities.
Help to regulate water temperatures by providing shade, maintaining a healthy environment for aquatic life.
Function as important terrestrial wildlife habitat and control the aquatic ecosystem of streams. Plant material that falls into the stream provides food for many species of small aquatic animals.
Provide a safe pathway for wildlife.

According to the National Research Council, restoration of vegetative buffers along America's water bodies should be a national goal "because their restoration can have a major influence on achieving the goals of the Clean Water Act, the Endangered Species Act, and flood damage control programs." The following suggestions are just a beginning, to promote dense vegetation to reduce runoff and trap contaminants:

Stop mowing and cutting vegetation as far out from the stream as possible. To be effective, the buffer should be at least 35 feet, but wider is better.
Restore eroded stream banks with help from a professional.
Don't straighten channels or place rubble or riprap on stream banks.
When you disturb the earth, always observe state and local ordinances and get proper permits.
Manage organic wastes so they don't pollute streams—keep grass clippings away from them; locate compost piles on flat surfaces away from streams or drainage areas; and keep animal waste away from streams, riparian areas, ponds, and paved areas.
Minimize use of pesticides and chemical fertilizers, and apply only as much organic fertilizer as recommended by a soil test.

If you're a farmer, check out the Conservation Reserve Enhancement Program (CREP), which reimburses farmers for protecting streams, ponds, and wetlands from damage from livestock and crops. Restoration of water bodies can have a major influence on achieving the goals of the Clean Water Act, the Endangered Species Act, and programs that control flood damage.

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