Bioretention Urban Stormwater Management Low Impact Redevelopment Pennsylvania

Prepared by Mr. Brian Oram, PG

Best Management Practices BMPs in Pennsylvania
Redevelopment of Urban Areas and Low Impact Planning Development Rural Areas
Keep Rural Areas Rural

Bioretention/ Rain Garden
Source: http://www.dnr.state.wi.us/

Biorention Swales
http://www.co.monroe.in.us

Figure 1. Bioretention Units and Rain Water Gardens

Water Gardens and Bioretention Systems

Rain gardens are small-scale bioretention systems that be can be used as landscape features and small scale stormwater management systems for single-family homes, townhouse units, and some small commercial development. These units can not only provide a landscape feature for the site and reduce the need for irrigation, but can be used to provide stormwater depression storage and treatment near the point of generation. These systems can be integrated into the stormwater management system since the components can be optimized to maximize depression storage, pretreatment of the stormwater runoff, promote evapotranspiration, and facilitate groundwater recharge. The combination of these benefits can result in a decrease in the peak flow and total volume of runoff generated by a storm event. In addition, these features can be designed to provide a significant improvement in the quality of the stormwater runoff, see Figure 1.

These units can also be integrated into the design of parking lots and other large paved areas, see Figure 2. This system provides "green area" composed of either native vegetation or landscape materials that are suited to a significant variation in moisture and temperature.

Figure 2. Bioretention in Parking Lot- Design is not perfect, but improvements
are needed with respect to inlet structure and creating a forebay.
These systems may need to provide more control for oil/grease.
Source: http://www.co.monroe.in.us/stormwaterquality/bioretention.html

Figure 3. High Density - Bioretention System (St. Paul, Minnesota)
http://www.lid-stormwater.net/bioretention/biohighres_home.htm

Filter Strips and Swales

Filter strips and swales are either elongated bioretention systems or vegetated areas that are located in transition zones. These transitions zones help to reduce the rate of runoff by creating detention storage and promoting the infiltration of the stormwater. The effectiveness of the application to stormwater management is a function of the hydraulic design of the bioretention system.

Figure 4. In Seattle, -Graded Swales created using
an amended soil reduced stormwater volume by 97 %.
Source: http://www.psat.wa.gov/Publications/LID_studies/amended_soils.htm

These units or systems can be developed into curbside bioretention areas.

Green Roofs

Green roofs, also called "vegetated roof covers," "living roofs," or "eco-roofs," are thin layers of living plants that are installed on top of conventional roofs. Properly designed, they are stable, living ecosystems that replicate many of the processes found in nature. Green roofs can control stormwater runoff, erosion, and reduce pollution. This results in improved water quality in local streams. In addition, the systems can reduce heat loss, reduce the air condition costs, increase roof life, conserve energy, provide a sound barrier, provide habitat, and provide an unique aesthetic environment in an urban area.

Green Roof Systems
Roof Scapes
Green Roof.org

Use of Porous Pavement

Porous Pavers

Porous Asphalt / Standard Asphalt

Porous Pavement or porous paving structure may be excellent material for walkways, sidewalks, patios, along shoulders of roads and paved areas (curb and channel units), use as entrance areas to bioretention systems, driveways, and possibly as an alternative to conventional paving. The porous units could include: porous asphalt, pervious concrete, open-celled paving grids, open-graded aggregate, open-jointed paving blocks, plastic geocells, soft paving materials, and porous turf.

For more information of Porous pavement and pavers please visit,

Stormwater | Porous Asphalt
More on Porous Pavement.

Interesting Links

Low-Impact Development and Stormwater in Pennsylvania
Low Impact Development
Chester County Stormwater BMP Tour Guide

PACD- PA Handbook of Best Management Practices
Draft Soil Erosion and Sedimentation Control Manual for Agriculture
EPA - Non-Point Source
Villanova University Urban Stormwater Partnership
PADEP - Stormwater Resources
NJ Stormwater.org
F.X. Browne Inc - Stormwater Management
Stormwater Best Management Practices/Design - Pennsylvania
Protecting Water Quality in Urban Areas
Preventing Stormwater Runoff Problems Through Watershed Land Design
Urban Small Sites Best Management Practice (BMP) Manual
National Stormwater Best Management Practices Database
Runoff Management Models
Distance Training Courses for Engineers