“These are the go-to practices for meeting regulatory requirements while adding aesthetic value.”
Edward Confair, PE, RLA, Engineering and Land Planning Associates, Inc.
What are they?
Small landscape practices are garden-like systems designed to capture, store, and infiltrate stormwater on a small scale, often in yards or parking lots, next to buildings, in the right-of-way, or in other locations where space is constrained. They offer flexibility in terms of overall site design and may in some cases offer the opportunity to increase the site’s developable area by locating stormwater management areas in the same footprint as planned landscape areas. Pollutants are removed by settling and filtration through plants, soil, and in some cases stone layers. These systems may be connected to sewer systems through an overflow structure or an underdrain, but usually are designed to infiltrate the collected stormwater runoff within a short period after the storm has ended. Some shallow ponding (six inches or less) may briefly occur on the surface during that time. In addition to reducing the volume of stormwater runoff, small landscape practices remove pollutants and improve water quality. Mulch and soil can trap certain contaminants, while soil microorganisms and plants reduce organic pollutants like nitrogen and phosphorus. When planted with native grasses and shrubs, these systems can provide micro-habitats for birds and other pollinators like bees and butterflies.
When are they used?
Small landscape practices can be designed to create visual appeal and enhance passive recreational opportunities in your development project. They are flexible in terms of site design and are often located in public-facing or high traffic areas and are often planted with a dense and colorful plant palette to maximize visual appeal.
What are some key considerations?
- Planting design as well as location and structural elements dictate appearance, which can range from meadow-like to ultra-formal with structured landscaped beds.
- These types of practices tend to be susceptible to sedimentation from roads and parking areas, and should not be designed to manage very large drainage areas.
The following small landscape practices are described in further detail in this section:
- Bioretention Basin
- Rain Garden
- Curb Bumpout
- Vegetative Filter Strip
- Grass Swale
- Downspout Planter
- Tree Trench / Tree Box
Further information on green infrastructure design standards can be found in the NJ BMP Manual.