Stream Buffers: All Topics
The text below includes all the major topics available on the Stream-Buffers page, except for news items.
About Stream Buffers
What Does Buffer Do for Suburban Streams?
Stream buffer helps control stormwater run-off—the water that rushes off lawns and streets during downpours. Run-off is an enormous but largely hidden environmental problem in urban and suburban landscapes.
Because so much of suburbia consists of buildings, roads, parking lots, and bulldozer-compacted turf, our landscape now absorbs relatively little water, compared to what it once did when it was less paved and more forested. When it rains on the ‘burbs, a much smaller proportion of the water is now retained by plants and soils, and a much larger proportion runs into the streams. (It’s true that storm sewers capture a large share of run-off, but that only delays its movement into the streams. Stormwater systems are not surrogate forests: They cannot return large quantities of water to either the atmosphere or the soil, the way riparian forests and meadows do.)
All this run-off contaminates streams with pollution from roads and lawns. It also washes in eroded soil and erodes the stream channels themselves, sometimes dropping them so low that they lose their natural connection to their flood plains. Run-off also raises stream water temperatures, because run-off is usually warmer than groundwater, which is the natural source of most stream water. This “thermal pollution” makes streams uninhabitable for many native aquatic organisms. There are secondary effects too. For example, the thermal pollution reduces the amount of oxygen dissolved in the water, as does the nitrogen and phosphorous pollution from lawn fertilizer, animal waste, and eroded soils. (Such “nutrient pollution” promotes algal growth; subsequent decomposition of algae consumes oxygen.)
Taken together, the pollution, deposition of sediment, erosion, warming, and oxygen depletion have had a ruinous effect on suburban stream ecology. In many parts of the DC area, our streams are becoming little more than stormwater ditches.
Riparian buffer can help absorb, diffuse, and filter run-off. Unfortunately, suburban streams often have very little buffer, and sometimes none at all. Many streams in the DC area are bordered for parts of their length by nothing but mowed turf, a highly unnatural condition. Even where buffer remains, it is often badly infested with invasive alien plants, which suppress native plants and compromise the development of forests and meadows.
Of course, buffer restoration cannot, on its own, return damaged streams to health. The volume of run-off is too great for that—and buffer-planting space is too small. But buffer restoration does reduce, to one degree or another, all of the run-off problems mentioned above. (The degree of benefit depends on site conditions and the buffer’s density and width.)
Buffer restoration confers other benefits too. Buffers expand our native forests and meadows. Buffers create more habitat for both terrestrial and aquatic wildlife. And buffers are very cheap to install and maintain, compared to other forms of stormwater management.
Rural Streams Need Buffer Too
You might think that rural streams are bound to be in better shape than suburban ones, because the rural landscape has more forest and meadow—and fewer buildings and parking lots. This smaller proportion of impervious surface does mean less of a run-off problem but, unfortunately, that advantage doesn’t always translate into healthier streams.
Many rural streams also lack buffer, especially on farmland. On dairy or beef farms, for example, pasture often extends all the way to the stream bank—a condition that is no more natural than suburban turf-to-bank conditions. Streams that flow through pasture are often damaged by cattle. In such places, a great deal of manure usually ends up in the stream, and the cattle trample the channel. The trampling disturbs the stream bed, contributes to erosion, and tends to widen the channel; the wider channel, in turn, increases the water’s exposure to sunlight, thereby raising the water temperature. Many farmland streams are badly damaged by this combination of stream-bed disturbance, erosion, nutrient pollution, and thermal pollution.
Here too, buffer restoration can help. Buffer can reduce erosion, absorb nutrient pollution, and cool the water by shading the channel. And because rural drainages have less in the way of impervious surface, rural buffer projects may create stream conditions that are more natural than is possible in suburbia. Better conditions may allow for the return of native organisms that cannot tolerate suburban streams, no matter how well buffered—organisms like eastern brook trout, or certain native mussels. By buffering their streams, farmers can create big opportunities for conservation.
Stream Buffer Plantings
The Sangha’s first stream-buffer project dates from 2002, when we began work at Wilburdale Park, in the Annandale section of Fairfax County, Virginia. Wilburdale is a small, mostly forested park that encloses a portion of Backlick Run, a major stream in the Cameron Run drainage. At Wilburdale, as at many other parks, we are working to control invasive alien plants and reestablish appropriate native species. Our planting stock comes from local, wild-collected (“local-ecotype”) seed grown out at our Wild Plant Nursery. For more information on our work at Wilburdale, see the Special Places page. Our early experiences at Wilburdale are also described in our booklet, Reconnecting Forests and Streams, which we published in 2005.
Fairfax County’s Buffer Program
In 2005, Fairfax County launched a county-wide initiative to restore stream buffer. At roughly 400 square miles, Fairfax County is one of the largest jurisdictions in the DC area. Much of the county is heavily developed, and suburbia has not been kind to the streams. A 2004 assessment concluded that only 20 percent of the county’s streams were in “good” or “excellent” condition. That’s down from 23 percent in a previous survey, done in 1999. At the other end of the scale, 63 percent of the streams were in “poor” or “very poor” condition in 2004—up very substantially from 45 percent in 1999.
The County’s buffer project ran from January 2005 through April 2009. The project recruited large numbers of volunteers to plant a wide range of native, riparian trees, shrubs, and herbs (nonwoody plants) on buffer-deficient riparian sites. Nearly all of these sites are on land owned by the Fairfax County Park Authority. In addition to planting, volunteers also worked to control invasive alien vegetation on some sites. The program was run by the Stormwater Planning Division of the Fairfax County Department of Public Works and Environmental Services. The Earth Sangha implemented the program; we did most of the planting design, logistics, volunteer outreach, event supervision, and maintenance of the plantings. As the program progressed, an increasing proportion of the planting stock came from our own nursery. (Because our nursery stock is local-ecotype, its use improved the biological value of the program.)
Funding for the program ran out in spring 2009. (In 2008, the County’s Stormwater Planning Division had begun work on a Request for Proposals to extend the program under a new contract, but this idea was eventually abandoned in the wake of the economic downturn.) By the time the program ended, about 10,000 plants, representing over 80 species, had been planted on about 30 sites covering over 18 acres, along more than 2 miles of stream bank. Over 1,500 volunteers had participated. Many of the Fairfax County buffer sites are included in our DC-Area Field Map; you can see some of our work on these sites by viewing the stream-buffer slide shows listed in the links panel of the main Stream-Buffer page.
Since nearly all of the program sites are on County parkland, the Sangha has been working with the Fairfax County Park Authority to maintain, improve, and expand the plantings.
Beyond Fairfax County
Our buffer effort is also reaching some lands owned by other agencies and jurisdictions. We are collaborating with the Bureau of Land Management to restore buffer along Thompson Creek, in the BLM’s Meadowood Recreation Area. Meadowood is on the Mason Neck Peninsula in southern Fairfax County. For more information on our work there, see the Meadowood page. In Arlington County, we are collaborating with the National Park Service at the Roaches Run Wildfowl Sanctuary, to restore native riparian plants along the shore of the Sanctuary’s tidal pond. And in 2010, we collaborated with Trout Unlimited to restore buffer to a couple of sites along the Thornton River, in Rappahannock County, Virginia.
Volunteering
Please check our News and Field Schedule pages occasionally for stream-buffer updates. In addition to planting events posted on the field schedule, we are always looking for volunteers to help maintain sites. Maintenance usually involves some control of invasive alien plants, resetting tree shelters, and occasionally picking up trash. Volunteers can work on multiple sites, or they can “adopt” a site of special interest. If you would like to help, please get in touch! For more information on volunteering with the Sangha, read the Volunteer page.
Partners
Our Partners for 2010 and Later
(2010 is after the Fairfax County Stream-Buffer Program closed.)
We are grateful to the following organizations, schools, companies, and government agencies, whose staffs have participated in our buffer work, or who have provided funding and operational support for our efforts.
The Arlington Four Mile Run Americorps Crew,
The Arlington Master Naturalists,
Boy Scout Troop 1128,
The Bureau of Land Management - Eastern States,
The Canoe Cruisers Association,
CGI volunteers,
The Chesapeake Bay Restoration Fund of Virginia,
EPA volunteers,
The Fairfax County Park Authority,
Fairfax Releaf,
George Mason University volunteers,
George Washington University volunteers,
Girl Scout Troop 4259,
Greater DC Cares,
HDR Architecture volunteers,
Lake Braddock Secondary School volunteers,
Lutheran Colleges Washington Semester volunteers,
Mount Vernon Farm,
The National Park Service,
The Park Fairfax - Woodlands Community Association,
RappFLOW,
South County Secondary School volunteers,
Trout Unlimited,
United Nations Foundation volunteers,
Virginia Master Naturalists, and
Virginia Native Plant Society volunteers
And, of course, we thank all the volunteers from the Sangha’s own volunteer network! Together, we are conserving the myriad native plants and animals that inhabit our streams, forests, and meadows. We are very grateful to all of our collaborators.
Our Stream-Buffer Partners from 2005 through 2009
(During the Fairfax County Stream-Buffer Program.)
In addition to our colleagues in the Fairfax County Stormwater Planning Division and Park Authority, we are grateful to the following organizations, schools, companies, and government agencies, whose staffs have participated in the buffer restoration program through 2009.
The Canterbury Woods Community Association,
Church of Latter Day Saints volunteers,
Fairfax Releaf,
Greater DC Cares,
Lands and Waters,
The National Wildlife Federation,
The Northern Virginia Conservation Trust,
Northern Virginia Interfaith Alliance volunteers,
The Potomac Conservancy,
Vienna Moms Club volunteers,
Annandale High School volunteers,
Lake Braddock Secondary School volunteers,
National Cathedral School volunteers,
The New Century College at George Mason University,
South County Secondary School volunteers,
AOL volunteers,
Fitness and Health volunteers,
HSBC Finance Corporation volunteers,
Network Solutions volunteers,
EPA volunteers,
The Northern Virginia Soil and Water Conservation District, and
The Virginia Department of Forestry
We also thank our many unaffiliated volunteers. Here and there throughout Fairfax County, little patches of riparian forest and meadow are once again beginning to enclose our streams—a legacy of our volunteers’ effort and generosity. We are very grateful to them all.