The Green Highway Partnership (GHP) was started in 2006 through leadership from U.S. Environmental Protection Agency Region 3 and others who understood the value of green practices focusing on mitigating environmental impacts in transportation corridors. The four areas of focus by the GHP include watershed driven stormwater management; recycling, reuse and renewable materials; conservation and ecosystem management; and lifecycle energy of highways.
Fast forward to today, and we now have a greater understanding of projected future precipitation patterns, and more significantly, more appreciation of the significant risks posed by flood events. However, many DOTs and other transportation agencies across the country have yet to formalize design standards that account for climate change impacts. Planning for climate change is one thing but to design and construct projects that account for these dynamics is another.
Developing dialogue
The driver for many existing stormwater-oriented projects in the transportation right-of-way is water quality oriented with the immediate goal of meeting an MS4 permit or TMDL requirement. While climate change and the anticipated impacts on precipitation patterns were recognized as legitimate concerns, hydrologic and hydraulic analysis and associated stormwater management designs did not account for these impacts as details were not yet developed.
Along with updated design standards, there is a need for a dialogue within the stormwater sector on what “success” means in the context of resilience in the face of climate change. If this answer is simply to increase the size of conveyance and treatment systems, we will be missing the mark. Solutions in the future will require nuance and tough choices that consider which areas we may allow to be inundated for what period time and at what frequency. Budgets are already limited in efforts to address existing needs, so over-building as a default to account for future needs may be seen as a luxury today that we cannot afford for tomorrow’s benefit
Searching for solutions
We will have to understand how innovations, such as continuously monitored automated control (CMAC) systems, can be utilized in a way that can be adapted in the future to accommodate new precipitation regimes. We will have to identify “sacrifice zones” where inundation will be permitted, and we will have to consider equity impacts as well as financial impacts. We will have to consider how single projects can be designed to provide multiple benefits that include not only water quality treatment and water quantity management but social and ecosystem benefits as well.
In the transportation sector, there is an opportunity to implement a significant number of these multi-beneficial projects through funding provided in the Bipartisan Infrastructure Law. A significant increase in funding for resiliency projects has
been enabled through the Promoting Resilient Operations for Transformative, Efficient, and Cost- Saving Transportation (PROTECT) Program. The program was established to increase system resilience from climate events. Funding for this program was authorized at $8.7 billion over five years with these funds disbursed through both competitive grants and formula-based allocations to states. The first round of funding from this program was kicked off via competitive grants this past summer.
As the recent Water Environment Federation (WEF) MS4 Needs Assessment Survey findings highlight, the stormwater sector is starting to enter into a phase of asset replacement, as the first generation of many stormwater projects are at or near the end of their design life. It is imperative upon us, as stormwater practitioners, to not just replace these stormwater assets in an in-kind context but look to integrate resilience as well as water quality treatment into these facilities. Our sector can add value to our communities in a multi-purpose fashion, which should always be our goal when possible.
