Top 5 Stormwater Management Techniques

Stormwater management is becoming an integral part in new construction, and is incorporated into the design of the building and its surrounding areas. Low Impact Development, (L.I.D.) practices contribute significantly to reducing stormwater runoff.  Here are 5 Stormwater Management Techniques to use when designing a L.I.D. adapted from San Diego’s Stormwater management manual.

The key techniques focus on making more pervious areas, and directing runoff from impervious areas into pervious ones.

1. Optimize site layout

   • Utilize topography to optimize the site layout and reduce the need for grading.
   • Identify soils with high infiltration capacity and, if possible, locate storm water treatment facilities in these locations
   • Preserve significant trees, especially native trees and shrubs, and identify locations for planting additional native or drought tolerant and large shrubs.

2. Minimize impervious surfaces

   • Construct walkways, trails, patios, overflow parking lots, alleys and other low-traffic areas with permeable surfaces. Such permeable surfaces could include pervious concrete, porous asphalt, unit pavers, or load-bearing geogrids like Ecoraster.
   • Minimize the use of impervious surfaces in the landscape design.
   • Increase building density (number of stories above or below ground) through design of compact and taller structures.

3. Disperse runoff to adjacent landscape areas

   • Drain rooftops into adjacent landscaping areas.
   • Drain impervious parking lots, sidewalks, walkways, trails, and patios into adjacent landscaping areas.
   • Use depressed landscaping areas, vegetated buffers, and bioretention areas as amenities and focal points within the site and landscaping design.

4. Design and Implementation of Pervious Surfaces

   • Consider the implementation of permeable pavements into the site design. Identify locations where permeable pavements, such as Ecoraster, unit pavers, pervious concrete, or pervious asphalt could be substituted for impervious concrete or asphalt paving.
   • Use permeable paving in parking lots and fire access routes (ensure load bearing capacity of permeable paving is adequate.
   • Landscape the permeable walkways and parking lots with vegetation to increase the aesthetic appeal, and increase water infiltration.

5. Construction Considerations

   • Minimize the compaction of soil when heavy machinery is used on the construction site.
   • Use of temporary roads, such as Ecoraster provide a stable surface for heavy machinery while displacing the load onto a wide area, preventing the soil compaction and rutting that usually occurs at construction sites.
   • Implement soil amendments. Landscape topsoil improvements play a significant role in maintaining plan and lawn health