Water is essential to life on Earth.  The world over, living things flock to water – to lakes, to rivers, to streams, to oceans.  Humans are no exception.  Our ancestors, in searching for appropriate settlement locations, always settled near a source of water.  Although today, through modern technologies, humans need not live on the banks of a river, we would be remiss to forget how integral waterways are to the sustenance of happy, healthy societies.

With that in mind, let’s consider Loudoun’s streams.  There are roughly 1,500 miles of perennial streams flowing through our county, coursing through our forests and behind our homes.  These streams flow into Loudoun’s reservoirs, into the Potomac River, and into the Chesapeake Bay; their waters ultimately provide nearly 300,000 Loudoun residents with drinking water.  They are part of a complex riparian ecosystem that is home to a wide variety of salamanders, fish, insects, birds, trees, and mammals.  These are the streams where our children caught their first fish and learned how frogs develop.  Our streams are a natural resource, a place to fish and to hike, to connect to the land, and to enjoy nature year-round.  And they’re being degraded.

According to a 2009 assessment by the county, 78% of Loudoun’s 1,500 miles of perennial streams are classified as either “stressed” or “severely stressed.”[i] The cause?  A number of factors, but principally bank erosion and runoff contaminated by sediments, excess nutrients, and animal waste.

Take a look at the following streams…  Which one looks healthier?

This one?

Or this one?

The most obvious difference between these two streams is the presence or absence of a “riparian buffer” – a strip of vegetation abutting the stream on either side.  These buffers act as a sponge for silt, animal waste, and excess nutrients, and slow the flow of water from land to stream, preventing contamination, sedimentation, and bank erosion.  In study after study, riparian buffers have been shown to be the most effective means of reducing the levels of sediment and nutrients that enter streams directly via runoff from the surrounding land.

Take a look at the chart below from a 1995 study of riparian buffers.[ii]

Percent reduction = 100 x (Input – Output) / Input

As you can see, the size and type of buffer greatly impact its effectiveness: wider buffers, with more – and more complex – vegetation better protect streams by reducing the loads of sediments and nutrients (i.e. nitrogen and phosphorus) that make it to the water.

Our streams are one of our greatest resources.  They are a community treasure worth safeguarding, as the health and happiness of our county depends on the quality and quantity of water flowing in our streams.   We of the Clean Streams Coalition firmly believe that the implementation and preservation of riparian buffers is absolutely necessary to the protection of Loudoun’s streams.

Want more information?  The following links provide excellent explanations of the benefits of riparian buffers in our community.


[ii] from Lowrence, R., et al, Water Quality Functions of Riparian Forest Buffer Systems in the Chesapeake Bay Watershed, 1995.