Why Cities Need to Share Stormwater Data

Urban stormwater, the rainfall that runs off of streets, buildings, and parking lots, is one of the major threats to the health of rivers, lakes, and coastal areas in the United States. When the rain hits these roads in cities, it sweeps toxins like gasoline and oil into our waterways, where they harm plants, fish, and other aquatic life. When we eat fish, we ingest these toxins. Additionally, since rainwater can’t soak into concrete sidewalks and streets, it rushes off quickly, overrunning water drains and causing flooding. Although federal rules like the Clean Water Act require water quality monitoring, local decisions about managing stormwater often lead to a surprising problem. Many cities collect data on stormwater control measures (SCMs), but this data can be inconsistent and is not always shared with the public. This research article highlights why this issue is significant, and it demonstrates how inconsistent terminology and statistics can hinder progress. It explains how sharing stormwater data across cities could improve stormwater management.

Stormwater control measures are physical systems, such as rain gardens and stormwater holding ponds, that are designed to manage flooding, improve water quality by filtering out pollutants, and lessen impacts on natural waterways. These are valuable systems for cities dealing with urbanization and climate change. Although many cities utilize stormwater control systems, there is no standard way to record their names or their impact. Different cities use many different terms for the same technology, making it difficult to compare their methods of stormwater control. For example, in a study across 23 US cities, the researchers found 378 distinct SCM terms, even though many systems had relatively the same function. Some of the same names were used in a few cities, but most cities had unique terminology. This variation is important because stormwater issues, such as the amount of runoff and water quality, are what researchers and engineers need to understand if they want to improve or design new stormwater systems. This can be difficult when what one city calls a “rain garden” another calls a “bioretention.”

If cities standardized these stormwater control systems, there could be a lot of improvements in these systems. For starters, cities can learn from each other's SCMs: they can avoid repeating the same mistakes and compare strategies to see what works best. With more consistent data, they can improve research and analyze what SCMs work best in different situations, such as climate, urban density, etc. These facts can lead to better urban planning, where stormwater controls can be built based on what would be optimal and not a mere guess. Today, many cities keep these records locked away, and some don't even keep completed inventories at all. Instead of sharing this data and sharing it as a resource, it unfortunately remains isolated.

The authors argue that instead of trying to standardize the names of SCM technology, cities should instead try to standardize the function and purpose of the technology. This would include terms like detention, infiltration, and pollutant removal for stormwater systems. These terms can be just as, if not more, useful than labelling each system. This is because it allows for more flexibility in how each system is built while still maintaining a sense of familiarity.

The message of this article is simple: stormwater management isn’t just about developing solutions, but it’s also about how we document, share, and learn from these solutions. By keeping uniform records of stormwater controls, cities can create more effective systems. The sharing of information can lead to better planning across the nation, especially for smaller cities that do not have as many resources to evaluate their own stormwater measures.

About the research:

Choat, B., Pulido, A., Bhaskar, A.S., Hale, R.L., Zhang, H.X., Meixner, T., McPhillips, L., Hopkins, K., Cherrier, J., and C. Cheng. 2022. A Cross-City Comparison to Understand Selection of Stormwater Controls in United States Cities. Journal of Sustainable Water in the Built Environment, in press.