The JDW Sustainable Landscape Program establishes a performance-driven standard for residential sites where water movement, soil stability, and long-term landscape function govern design and construction. The program prioritizes controlled runoff, predictable infiltration, erosion resistance, and durable transitions between built and planted systems.
Unmanaged water movement leads to soil loss, shoreline degradation, and structural stress. This standard mitigates those risks through integrated grading, drainage, planting, and soil systems designed to function across repeated wet–dry cycles.
Each project begins with a comprehensive site and water read to determine how water currently enters, concentrates, and exits the property.
Assessment includes:
Slope direction and grade changes
Roof runoff volumes and discharge points
Hardscape flow paths and driveway runoff
Upslope inflow from adjacent properties
Soil texture, permeability, and compaction
Concentration points along structures, fences, and grade breaks
Existing discharge locations including storm connections and waterfront edges
This assessment establishes target flow paths and identifies areas requiring interception, infiltration, or structural control.
Water routing is selected based on site constraints and downstream sensitivity, using a tiered approach.
Surface Shaping and Swales
Where feasible, runoff is managed through grading and swale formation.
Typical specifications:
Longitudinal slopes of 1–4%
Broad, shallow profiles to reduce flow velocity
Compacted subgrade shaped to maintain positive drainage
Vegetated finish using deep-rooted native species
Swales are aligned to move water away from structures and toward infiltration zones or stable discharge points.
Subsurface Drainage Systems
Where surface shaping alone cannot control runoff, subsurface drainage is installed along identified flow paths.
Typical components:
4”–6” perforated PVC or SDR-35 pipe
Washed aggregate drainage fields (ASTM No. 57 stone)
Non-woven geotextile fabric separating native soils from stone
Cleanouts at changes in direction or grade
Subsurface systems intercept water before it destabilizes slopes or reaches foundations and route it toward controlled discharge areas.
Infiltration is integrated into routing where soil and slope conditions support predictable absorption.
Runoff mitigation methods include:
Routing water through planted depressions and swales
Passing flow through amended soil zones composed of:
50–60% coarse sand
20–30% organic compost
10–20% native topsoil
Surface mulch layers at 2–3” depth to trap sediment and slow flow
Routing subsurface discharge through vegetated areas prior to final outlet
These systems reduce sediment transport, filter nutrients, and lower peak runoff velocity before water reaches downstream systems or waterfront edges.
On water-adjacent properties, retaining structures are used to stabilize grade transitions and protect shorelines from erosion.
Typical retaining wall systems include:
Segmental concrete block walls with geogrid reinforcement sized for retained height
Natural stone or stone veneer over a reinforced structural core
Footings placed below frost depth and bearing on compacted subgrade
Free-draining backfill composed of washed aggregate
Integrated drainage behind the wall using a perforated pipe wrapped in geotextile
Runoff is intercepted upslope of retaining walls and routed through drainage systems and planted infiltration zones to prevent direct discharge over wall faces and reduce shoreline scouring.
Soil systems are built to support infiltration, root development, and long-term stability.
Typical soil compositions include:
Infiltration and swale zones:
50–60% coarse sand, 20–30% compost, 10–20% native soil
Planting beds (upland):
Native sandy soil amended with 20–25% organic compost by volume
Shoreline and slope zones:
Native sandy soil blended with compost and stabilized with deep-rooted vegetation
Soil amendments are mechanically blended to a uniform depth to avoid layering and perched water conditions.
Planting work uses native Maryland species selected for sandy soils, water tolerance, and erosion resistance.
Stormwater and Swale Planting
Soft Rush (Juncus effusus)
Fox Sedge (Carex vulpinoidea)
Switchgrass (Panicum virgatum)
Blue Flag Iris (Iris versicolor)
Erosion Control and Slopes
Little Bluestem (Schizachyrium scoparium)
River Oats (Chasmanthium latifolium)
Prairie Cordgrass (Spartina pectinata)
Shrubs for Structure and Stabilization
Silky Dogwood (Cornus amomum)
Buttonbush (Cephalanthus occidentalis)
Inkberry (Ilex glabra)
Bayberry (Morella pensylvanica)
Groundcover and Soil Protection
Pennsylvania Sedge (Carex pensylvanica)
Green and Gold (Chrysogonum virginianum)
Wild Strawberry (Fragaria virginiana)
Partridgeberry (Mitchella repens)
Defined transitions prevent material migration and maintain long-term clarity between systems.
Typical edge methods:
Steel or aluminum edging at turf interfaces
Mow strips or hardscape transitions in high-use areas
Compacted trench edges in low-impact zones
Mechanical division reduces maintenance burden and preserves layout integrity.
Maintenance practices emphasize soil health and physical control methods:
Hand pulling and mechanical edging as primary weed control
Limited pre-emergent use where pressure persists
No routine synthetic fertilizer application unless site conditions indicate deficiency
Projects completed under this program demonstrate:
Controlled runoff and reduced erosion
Stable grade transitions near structures and shorelines
Improved soil resilience under wet–dry cycles
Reduced sediment and nutrient movement toward waterways
Lower long-term maintenance requirements
System performance varies based on soil composition, slope geometry, and upstream runoff conditions. Ongoing maintenance is required to preserve function.