Since the Environmental Protection Agency, and in turn state and local regulators, have gone all in on green infrastructure (GI) and low impact development (LID) concepts a seemingly regrettable consequence has emerged. Topics specific to the broader adoption and implementation of GI have monopolized our collective dialog on stormwater management of late. The predominantly positive press and barrage of GI heavy conference agendas seemingly suggest that if we apply GI far and wide then water quality impairments caused by urban runoff will soon be a thing of the past. GI provides stormwater practitioners with invaluable tools to aid in the stormwater fight, but many site specific challenges can’t be surmounted with GI solutions alone. To that end, should we be concerned that overemphasis on GI is discouraging innovation?
GI is routinely labeled as a cheaper, more effective and easier to maintain alternative to traditional gray infrastructure. Experience is revealing that sometimes that’s true, other times only partly true and in some cases GI is not the best or even a feasible solution. This knowledge has spawned yet another stormwater buzzword, smart gray infrastructure. The gist being to make smart investments in gray infrastructure where GI alone does not address impairments. The need for complimentary green and gray strategies is particularly high in urban areas where limited space, compacted or contaminated soils and existing infrastructure make GI deployment most challenging. Additionally, GI is often poorly suited for addressing large storms and the flooding they can produce. Knowing that gray solutions remain crucial stormwater tools should fuel a collective desire to deploy innovative solutions that maximize water quality benefits at the lowest possible life cycle cost.
Historically, innovation in stormwater has emerged from both the public and the private sector. It is not uncommon for the academic community to partner with the private sector to broadly deploy a promising innovation. It has been equally common for the private sector to work with the academic community to validate the performance of their in-house research through third party evaluation. With much of the academic community now focused squarely on GI research, those partnerships are becoming less common. In the private sector, where an entire industry was born in the wake of NPDES Phase II implementation, investment in R&D is made less appealing by regulations that put innovative solutions at the back of the BMP line regardless of how well they perform.
Expanded deployment and understanding of GI is a sensible goal, but GI isn’t going to fully address adverse stormwater impacts on every site. Accordingly, we should also be encouraging innovation in smart gray infrastructure by establishing flexible regulations that clearly define water quality goals and allow for the use of the BMPs that best address them given the site specific constraints in place. Encouraging innovation also means providing a path for new solutions to be evaluated and accepted as viable tools whether they’re green, gray, blue or brown.