This modern landscape architecture design establishes a “green line” that filters site runoff and creates a clear boundary between formal lawn spaces and a natural wetland buffer.

During the first 14 years the clients lived in their home, they witnessed the water quality of nearby ponds diminish and the beauty of larger waterways vanish. Extensive research revealed that polluted runoff from developed areas was having a detrimental impact on the environment. The modern landscape architecture solution features native plants complemented by buff-pigmented concrete, Tigerwood, brown flagstone and aluminum edging. It uses a single, bold design element, a green line, to filter site runoff and create a clear boundary between formal lawn spaces and the wild beauty of surrounding wetland ponds. This landscape design won an ASLA Minnesota Honor Award and a grant from the City of Plymouth, Minnesota for its beauty, innovation and ecological contribution to its neighborhood.

An existing boulder encircled by dry-stacked brown flagstone is transformed into a natural sculpture. The circular, sunken patio is made of pigmented concrete and dry-set flagstone. The two benches near this patio are constructed of FSC-certified Tigerwood.
Modern landscape architecture
featuring a green line for site runoff
Research began with a review of aerial maps. It revealed that runoff from the paved and turf areas of commercial and multi-family residential developments to the north was negatively affecting water quality. The particulate count in pondwater was increasing and water quality declining.
The materials palette consists of rich, brown flagstone, buff-pigmented concrete, Tigerwood, aluminum edging and native plants. Each programmatic space is defined by a circle to create areas of interest that also function as part of the site’s stormwater treatment system. Each planting zone showcases a monoculture of plants with bold colors and pronounced leaf patterns.

A custom-designed, contemporary chiminea fabricated from powder-coated aluminum mounted to a concrete pad transforms the sunken patio into a fire circle.
This infrastructure plan maps the site’s subwatersheds to quantify total water volume and show how runoff travels across the landscape. Light blue lines illustrate how roof runoff is directed into pipes that lead to the green line.
The roots of the Common Rush (Juncus Effusus) planted along the green line filter pollution out of surface water, which is further purified as it travels downward through open, angular rock wrapped in a geofabric cloth. A perforated pipe runs through the middle of this five-foot-deep trench. All downspouts are connected to hardline, plumbed pipe that plugs into this biofiltration system.
Seating is provided by the concrete bench on the perimeter of the fire circle and the Tigerwood benches, which are illuminated at night.
The formal, contemporary landscape provides outdoor spaces for entertaining, dining, and play.
To assure that the edges of distinctly different site elements line up cleanly, the Tigerwood deck is set into a recessed area of the concrete. An aluminum edging separates the turf from the mulched area that is planted with Feather Reed Grass. A Trumpet Vine climbs up the post toward a Tigerwood trellis.
The chocolate flagstone used throughout the site is quarried in Colorado where the homeowners were born.