- Center for Neighborhood Technology’s Green Values Calculator™ is a tool for quickly comparing the performance, costs, and some benefits of green infrastructure practices to those of conventional stormwater management practices. The calculator takes users 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 then choosing from a range of green infrastructure best management practices to find the combination that meets the runoff volume reduction goal in a cost-effective way.
- It includes the ability to calculate the costs of stormwater management before and after undeveloped land is converted to another use.
- The calculator provides construction, annual maintenance and lifecycle cost comparisons to manage a specified volume of stormwater for green infrastructure and conventional scenarios. The calculator also estimates some of the non-hydrologic benefits of using green infrastructure.