Trees vs. Arlington streams, by Gary Anthes

June 27, 2020

These pictures show the damage to Arlington streams – including the trails and trees alongside the streams – from excess stormwater runoff. These particular photographs were made along Gulf Branch between Military Road and the George Washington Memorial Parkway overpass, but similar scenes can be found along Pimmit Run, Donaldson Run, and other streams in Arlington County.

The pictures were taken just after the torrential rains that fell July 8, 2019. So, it might be tempting to say, well, what do you expect in a 100-year storm? But much of the damage shown here was made months and years earlier. In fact, every time it rains even moderately, the stream banks wash away a bit more. For almost 40 years I have walked my dogs along Gulf Branch Trail, a path constructed a long time ago by Arlington Parks & Recreation. I don’t remember much damage decades ago, and certainly the damage is accelerating now.

Tree loss is both a cause and an effect of the stormwater runoff problem. As trees (and permeable land) are removed elsewhere, storm water increases and does more damage to stream environments, causing the destruction of still more trees. The exact causes of this cycle are complex, and the solutions still more complex (and controversial). Peter Rousselot of Arlingtonians for Our Sustainable Future nicely summarizes these issues here: and here:

In places the Gulf Branch Trail has entirely washed away and been replaced by ad hoc tracks made by intrepid hikers around dangerous spots. Much of the trail is muddy, rough, and dangerous. After the July storm I met an elderly lady retreating from a point at which she felt unsafe to continue. She seemed disappointed that she couldn’t follow her younger and more nimble family members on their journey downstream.

That made me sad, as does the plight of our trees.