Common problem, creative solution
Attractive, yes. But the main role of this dry streambed is to funnel rainwater runoff from neighboring properties into the streetside storm drain.
In 1993, Barbara and Gordon Robinson asked me to design the landscape for their new home. The site included a drainage area that collected surface water from several adjacent properties in a depression, or swale, across the rear property line, then directed it along the side of the house to a storm sewer at the street. On new homesites nearby, efficient concrete flumes had been constructed to carry the effluent as swiftly as possible. But Barbara, a dedicated gardener, was unwilling to sacrifice plants for plumbing.
An initial plan to install a French drain buried beneath a pea-gravel path was discarded when the gravel rolled downstream in the first storm. I suggested a dry stream—a shallow swale lined with stone substantial enough to withstand a serious downpour. Large chunks of stone or concrete, termed rip-rap, are sometimes dumped on creek embankments to slow the speed of storm water and to prevent erosion. In a garden, the careful placement of water-worn stone, or river slicks, along a swale is more aesthetically pleasing and also provides an ideal place for plants.
Creating a dry stream that simulates a natural waterway is a job for a genuine craftsman, one who possesses the skill of an engineer and the eye of an artist. I suggested my clients meet with Rodney Clemons and Thomas Rice, whose work with stone in Japanese gardens and in naturalistic water features I had admired for years. After seeing the site, the team assured us they could construct an attractive and functional dry stream within the drainage easement, despite its rather narrow 10-foot average width.
The Robinsons’ builder had correctly set the grade of the site so that, with some fine-tuning by Rodney and Thomas, there was positive flow from a high point behind the residence to the street in front. Runoff is collected along the rear property line, in a shallow swale hidden in a buffer of densely planted evergreens. Wax myrtle (Myrica cerifera) and ‘Nellie R. Stevens’ holly (Ilex ‘Nellie R. Stevens’) are workhorse shrubs that screen this area effectively.
Before starting, Rodney and Thomas carefully laid out all the stone for the project on the adjacent vacant lot. They placed the first large boulders where the swale comes into view at the corner of the property. Then, like fitting together the pieces of an enormous puzzle, they positioned individual stones of various sizes and contours in a serpentine configuration along the side of the house.