Introduction

One of the primary environmental challenges of new developments is the increase in impervious surfaces, which, when it rains, leads to more polluted stormwater runoff. Clean water is essential for human health, ecosystems, and sustainable cities — and when rain falls on streets, sidewalks, and rooftops, it picks up contaminants and carries them directly into rivers, lakes, and oceans, usually with no filtration or treatment.

Traditional stormwater management systems focus on quickly moving water away through pipes and drains. While this prevents localized flooding, it does nothing to improve water quality. Instead, polluted stormwater enters natural water bodies unchecked, leading to a host of environmental and public health problems.

This is where green infrastructure solutions can help, offering a more sustainable approach with at-source stormwater management.

Stormwater and Polluted Watersheds

In most North American cities, stormwater management is typically an exercise in quick-whisk removal: gray infrastructure takes the runoff away from site as fast as possible. The rainwater hits the impervious surfaces (where it picks up contaminants), is ushered into the storm drain, and is transported — often untreated — directly into nearby rivers, lakes, or oceans.

This system does nothing to clean the water before it reaches our natural waterways. Instead, it transports pollutants directly into watersheds, including oils, grease, heavy metals, fertilizers, pesticides, bacteria, plastic and litter, sediment, and more. In cities with combined sewer systems (CSOs), the problem is even worse. During heavy rain, stormwater and sewage share the same pipes. When the system overflows, raw sewage is discharged into rivers and lakes, creating serious public health hazards.

Unchecked stormwater pollution has widespread consequences for the environment, public health, and urban resilience, including:

• Declining Water Quality: Excess nutrients (nitrogen and phosphorus) fuel harmful algal blooms, depleting oxygen and killing fish. Heavy metals and chemicals accumulate, making water unsafe for consumption and recreation. Sediment clouds waterways, reducing sunlight penetration and damaging aquatic plant life.
• Public Health Risks: Bacteria and viruses in stormwater runoff can lead to waterborne illnesses in drinking supplies and recreational areas. Microplastics from urban runoff enter the food chain, with unknown long-term effects on human health.
• Increased Flooding and Habitat Destruction Fast-moving runoff erodes streambanks, destroying aquatic ecosystems. High volumes of stormwater overwhelm drainage systems, leading to urban flooding. Wetlands and natural floodplains are lost, reducing their ability to absorb excess water.

If we continue relying solely on gray infrastructure, these problems will only worsen as climate change increases rainfall intensity and urban populations grow.

How Green Infrastructure Can Help

Nature-based stormwater solutions can slow, absorb, and filter stormwater before it reaches waterways. Instead of rushing pollutants into rivers and lakes, green infrastructure manages water at the source, reducing pollution and flood risks.

Soil, plants, and microbe naturally break down contaminants. Vegetation also performs evapotranspiration, absorbing and releasing water (which reduces runoff). And these trees and plants likewise help mitigate urban heat islands and store carbon.

Some of the most effective green infrastructure stormwater solutions include:

• Bioswales and Raingardens: Using plants to filter pollutants
• Silva Cell: Essentially an underground raingarden that uses tree planting soil for stormwater management
• Permeable Pavement: Rainwater soaks through where it falls
• Green Roofs: Absorbs rainwater, reducing runoff from buildings

By integrating these strategies into urban planning, cities can reduce water pollution while enhancing biodiversity, cooling urban areas, and creating more resilient infrastructure.

Marino Cell for Water Quality Improvement

DeepRoot’s latest innovation, Marino Cell, is an exciting development in stormwater management: a modular, high-strength system that stores, filters, and infiltrates stormwater at the source. How does Marino Cell help reduce stormwater pollution?

• Enhances Infiltration: Allows stormwater to soak into the ground, reducing runoff
• Prevents Pollutant Transport: Filters out contaminants before they reach waterways
• Works Alongside Other GI: Complements Silva Cells, bioswales, and other sustainable stormwater solutions

Marino Cell can also be installed nearly anywhere; this means we can manage stormwater in places that were never possible before.

Conclusion

Water pollution from stormwater runoff is a serious but solvable problem. Traditional stormwater systems focus on moving water quickly, but at the cost of water quality. Green infrastructure solutions like bioswales, permeable pavement, and Silva Cells help slow, absorb, and clean runoff at its source, reducing the burden on watersheds.

Marino Cell adds another layer of effectiveness, providing high-strength, underground stormwater management that not only prevents flooding but also improves water quality. By adopting sustainable, nature-based solutions, we can protect our waterways, build climate-resilient cities, and create healthier environments for future generations.

As cities plan for the future, the shift to green infrastructure must be a priority. Engineers, planners, and policymakers should integrate Marino Cell and other sustainable solutions into urban projects to ensure cleaner waterways and healthier communities.