When it rains or snows, the resulting runoff can collect pollutants including salts, fertilizers, chemicals, oils, and sediment, among other things. These contaminants have the potential to impair surface water and groundwater that receive the runoff. Communities in the United States face growing challenges to effective stormwater management as a result of aging infrastructure, increasing urbanization, changing climate, and shrinking budgets, among other factors. These changes have increasingly stressed existing “static” stormwater management systems, such as pipe networks and ponds, that are intended simply to convey storm flows to nearby receiving waters without regard to overall system conditions.
Dealing with these stressors requires innovative and resilient solutions such as real time control (RTC) or “dynamic” stormwater management systems. RTC systems are typically automated or semi-automated and involve the use of sophisticated dynamic models to operate stormwater controls in real time, such as modifying setpoints to open and close valves, or routing storm water differently under particular system conditions. The goal of an RTC system is to continuously regulate the flow in the various branches of a network based on real-time information related to system capacity and weather conditions, thus reducing the magnitude of outflows during storms and relieving other stresses on the system.
During a recent grant-funded project, an interdisciplinary team of Marquette law faculty, engineering faculty, and students from both disciplines studied dozens of examples involving RTC implementation in the United States and abroad. We also examined the literature detailing institutional barriers to RTC innovation. And we reviewed numerous legal decisions related to municipal liability for stormwater management (or mismanagement). Finally, we suggested a variety of strategies to combat these institutional and legal barriers to smooth the transition to RTC systems.
As an initial matter, we found that RTC systems have not been widely adopted. Some analysts have blamed historical resistance to innovation, especially among governmental system operators responsible for protecting public health and safety. Other factors that inhibit innovation include the risk-averse nature of water managers, the long life expectancy and significant complexity of most water systems, geographic and functional fragmentation, water pricing practices, absence of incentivizing regulations, and insufficient access to venture capital.
From this foundation, we distilled several institutional and legal barriers that prevent municipalities from embracing this innovative stormwater management systems. Key institutional barriers include regulatory fragmentation, workforce readiness, resistance to innovation, data management, cybersecurity, and cost. Municipalities considering RTC innovations must be ready to address those challenges.
On the legal side, two factors should concern a stormwater management system operator considering RTC: first, that by actively making decisions to control and route the flow of stormwater in its system, it increases the likelihood of liability for negligence or nuisance claims; and second, that the sheer amount of data collected by RTC networks effectively puts the municipality on notice of problems within its system, increasing the likelihood of legal liability connected with future claims.
In light of these concerns, our team performed a field study to evaluate how a detention pond augmented with an RTC valve at the outlet performed in terms of common stormwater design standards and regulatory criteria, including peak flow reduction and total suspended solids removal.
Some of the lessons learned in overcoming these barriers may be applicable to analogous situations involving other innovative technologies capable of improving public health and the environment.
Interested in learning more? The interdisciplinary project resulted in one publication in a law review (the Notre Dame Journal of Emerging Technology) and another in an engineering journal (the Journal of Sustainable Water in the Built Environment).
The project was funded through a grant from the National Science Foundation Industry/University Cooperative Research Center for Water Equipment and Policy