Making the Case for Green Versus Gray…and Trees Too!
Adopting green infrastructure practices – particularly as part of an integrated system – almost always will save on construction costs and maintenance over the long term. So how can you prove it?
For an overview of the various methods for measuring flow reduction associated with green infrastructure, see this recent draft paper from the Center for Watershed Protection, prepared in 2017 for the US Forest Service. The project demonstrates how existing hydrologic models can be modified to accommodate green infrastructure and trees, and assesses other methods to measure the functions, benefits and economics of green infrastructure.
Less Technical, Still Useful
Below we’ve listed some case studies which include cost analyses for gray versus green practices. And we urge you to tinker a bit with some of the calculators; they may be just what you need to show your colleagues why green infrastructure makes sense [and dollars]. Among the most useful, and user-friendly:
- Green Values®: National Stormwater Management Calculator
- A Similar Calculator Designed Specifically for Chicago BMP Requirements
- For a relatively recent review of green infrastructure modeling software, check out EPA’s recent review of available products. Note: most don’t include trees as green infrastructure. Minnesota’s Pollution Control Agency prepared an annotated summary of tools for use by stormwater managers in their state. Minnesota is also one of the handful of states that have adopted tree-specific BMPs in their stormwater management manual.
Click here for a list of alternative approaches to estimating the costs and benefits of green and grey infrastructure.
Types of Economic Analysis to Inform Policy Decisions
|Capital Cost Assessment||
|Life-Cycle Cost and/or Benefit Component||
|Fiscal Impact Analysis||
|Quantitative Ranking Based on Self-Described Non-Monetized Benefits and External Costs||