Articles / June 4, 2024

Water Works: A Smarter Approach to Stormwater Management

If you’ve been immersed in the world of urban stormwater management for long, you’ve probably noticed the persistent gap between our water-quality standards and practical capabilities to control stormwater pollution. It’s been more than five decades since the Clean Water Act articulated the goal of protecting and restoring the beneficial uses of our nation’s waters, and it’s been more than three decades since permitting authority for nonpoint pollution was added.

As municipal stormwater permits are updated, many are incorporating enforceable total maximum daily load (TMDL)-based water quality standards. Yet, as stormwater program managers strive to meet these obligations, they often run up against funding, staffing and information constraints that can make measurable progress elusive. At the individual project level, engineers and landscape architects often are frustrated by local permitting requirements that seem arbitrary, unnecessarily complex and prioritize conformity over creativity. Against this backdrop, the integration of smart technology with traditional infrastructure offers a beacon of hope.

Better Models

Within the municipal stormwater management community, technology-enabled opportunities for efficiency and cost reduction abound. Fundamental to the success of any program is the ability to measure and model systems accurately. Satellite-based remote sensing—complemented by LiDAR, drones and ground-based surveys—provides critical information for watershed modeling, including land cover and topography mapping and stormwater infrastructure details. Networks of simple sensors measuring important variables such as water level, flow rate and water-quality parameters provide the data needed to calibrate digital twins—virtual replicas of real-world systems.

These digital twins then can be analyzed to optimize asset management efficiency and plan for deployment of new stormwater control measures that maximize the benefit of precious capital improvement funds.

With advances in cloud computing power and data storage, running and analyzing thousands of retrofit scenarios to identify the optimal balance of cost and performance can be done quickly and without committing to long-term ownership of computing resources. With ongoing integration of real-world feedback and harnessing of machine learning capabilities, forecasting hydraulic and water quality responses to rain events improves through time.

Automated Management

Real-time adaptive management becomes possible when sensor and communication networks are mated with data analytics and management software that can run control algorithms to actuate valves, pumps and other powered infrastructure. Such active control strategies may optimize performance of existing infrastructure to minimize or even eliminate the need for new capital improvements.

For example, actively managing the volume of existing stormwater storage systems in response to forecasted weather events can significantly increase infiltration or rainwater harvest volumes while minimizing flood risk. Integration of stormwater infrastructure with wastewater and water supply systems is likely to require this level of technology integration and will be very familiar to partners working on those pieces of the “One Water” puzzle.

Municipal stormwater programs also can extend requirements to private land developers that will improve the resolution of their models and MS4 performance. For example, they can require as-built site information in a format that can be integrated with their GIS or hydrology and hydraulics models. They also can require integration of sensors into stormwater control measures that will collect and share operational information, including maintenance indicators. This sensor information can be used to improve accountability for proper operation and maintenance without requiring dedicated field-inspection crews. Municipal stormwater programs also can use social media and targeted advertising to educate the public as well as use digital platforms to gather data from citizen science efforts.

Exciting Times for Innovators

Land development project managers, whether in the public or private sector, are increasingly motivated to find innovative approaches that can shrink the size, cost and ongoing operational expense of stormwater-management infrastructure. From small-scale innovations such as smart irrigation systems and maintenance indicators to larger systems integrating real-time controls, adoption will accelerate as savings are demonstrated.

The fusion of technology with traditional stormwater management practices can usher in a new era of efficiency, accountability and innovation. Faced with a growing list of pollutants of emerging concern, climate change impacts, increased urbanization and aging infrastructure, it’s clear that municipalities, engineers and developers need new tools. Fortunately, advances in remote sensing capabilities, machine learning, battery efficiency, computing power and data storage, sensor cost reduction and real-time control systems are all moving forward simultaneously.