Green Values - National Stormwater Management Calculator

The National Stormwater Management Calculator is one tool found in the “Green Values” Stormwater Toolbox developed by the Center for Neighborhood Technology. The National Green Values Calculator (GVC) is focused on stormwater run-off reduction, and is a tool for comparing the performance, costs, and benefits of green infrastructure, or Low Impact Development (LID), to conventional stormwater practices. The GVC is meant for a single site, or a campus of buildings contained on a single site.

The GVC is designed to take the user through a step-by-step process of 

  • determining the average precipitation at a site, 
  • choosing a stormwater runoff volume reduction goal, 
  • defining the impervious areas of the site under a conventional development scheme, and
  • choosing from a range of Green Infrastructure Best Management Practices. 


The Green Infrastructure practices included that can provide runoff reduction benefits are: 

Green Roof

Planter Boxes

Rain Garden

Cisterns/Rain Barrels

Native Vegetation 

Vegetation Filter Strips

Amended Soil

Roadside Swales


Swales in Parking Lot

Reduced Street Width

Permeable Pavement on Parking, Driveways and Alleys, and Sidewalks



Related Organizations:

  • Center for Neighborhood Technology


Resource Category:

Resource Types:

  • Tool (general)


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