How Stormwater Detention & Retention Tanks Safeguard Our Communities

Every flood tells a story of unpreparedness: inundated homes, submerged roads, overwhelmed hospitals, and communities left to pick up the pieces. Stormwater runoff—the water that flows over roads, rooftops, and parking lots during heavy rainfall—has become an increasingly urgent challenge, exacerbated by urbanization, aging infrastructure, and climate change.

Unchecked runoff not only causes flooding but also carries pollutants like oil and chemicals into waterways, erodes landscapes, and endangers infrastructure. The consequences are more than financial; they’re deeply human—lives disrupted, businesses ruined, and ecosystems damaged. We cannot understate the need for efficient stormwater management.

Stormwater detention tanks offer a critical solution. By temporarily storing excess rainwater and releasing it gradually, they reduce flooding, protect public infrastructure, and improve water quality. In this guide, we’ll explore why these systems, combined with stormwater retention tanks, are essential, how they work, and why investing in stormwater management is no longer optional—it’s a necessity.

The Growing Urgency of Stormwater Management

Stormwater management failures in the United States have been catastrophic, exposing the vulnerability of aging infrastructure and the devastating cost of inaction. Here are just a few examples:

• Hurricane Ida (2021): Record rainfall overwhelmed New York City's stormwater systems, flooding subway stations and homes, causing 92 deaths and $75 billion in damages.
• Hurricane Harvey (2017): With 60 inches of rainfall, Harvey caused $125 billion in damage, destroying roads, bridges, and homes in Texas.
• Ellicott City Floods (2016 & 2018): Intense rainfall overwhelmed the town's stormwater infrastructure twice in two years, causing millions in damages and the loss of lives.

These events are not anomalies; they are interconnected. Climate change is intensifying storms, increasing rainfall, and pushing our outdated stormwater systems to the brink. The American Society of Civil Engineers estimates an $8 billion annual funding gap for stormwater infrastructure as of 2021 with a cumulative grade of C- on American infrastructure.

We can no longer afford to wait. Stormwater management solutions like retention and detention tanks must become a top priority for resilient cities and sustainable communities.

Stormwater Detention Vs. Retention Tanks

Retention and detention tanks are pretty similar to stormwater retention and detention ponds. One holds water (wet system) while the other drains it off (dry system).

What are Stormwater Retention Tanks?

Stormwater retention tanks are storage systems designed to collect and permanently hold stormwater runoff. Unlike detention tanks, retention tanks do not release water back into the drainage system. Instead, the captured water is either absorbed into the ground to recharge aquifers or reused for non-potable purposes like irrigation.

How They Work

• Collection: Stormwater is funneled into the tank from impervious surfaces like roads, roofs, and parking lots.
• Storage: Water is stored indefinitely, reducing runoff volume and preventing immediate discharge into waterways.
• Reuse or Infiltration: Retained water is either used for irrigation, cleaning, or industrial applications, or allowed to seep into the ground to replenish groundwater supplies.

Why Stormwater Retention Tanks Matter

Retention tanks offer unique benefits:

• Water Conservation: Stormwater retention tanks capture and store rainwater for reuse, reducing demand on municipal water supplies.
• Groundwater Recharge: By allowing water to infiltrate the soil, stormwater retention tanks help replenish aquifers, sustaining long-term water resources.
• Pollution Prevention: Retaining stormwater prevents contaminated runoff from reaching rivers and lakes, protecting aquatic ecosystems.
• Urban Sustainability: Retention tanks support sustainable urban development by turning stormwater from a liability into a resource.

Stormwater retention tanks are a vital component of stormwater management systems, especially in areas focused on water reuse and conservation.

What are Stormwater Detention Tanks?

Stormwater detention tanks are underground or above-ground systems designed to temporarily store stormwater during heavy rainfall and release it slowly back into the drainage system.

How They Work

• Collection: Runoff from roads, roofs, and other surfaces is diverted into the tank.
• Storage: Water is held temporarily to reduce the immediate burden on stormwater systems.
• Controlled Release: Water is discharged at a controlled rate, preventing downstream flooding.

By managing runoff in this way, stormwater detention tanks protect communities from the immediate impacts of storms while helping to preserve natural ecosystems.

Why Stormwater Detention Tanks Matter

The benefits of stormwater detention tanks go far beyond flood management:

Flood Mitigation

Flooding disrupts lives, damages property, and strains public resources. Stormwater detention tanks provide a buffer, giving stormwater systems time to handle excess water without being overwhelmed.

Improved Water Quality

Stormwater runoff carries pollutants like oil, chemicals, and trash into local waterways. Belowground and aboveground stormwater detention tanks act as a first line of defense, capturing and treating runoff before it can contaminate rivers and lakes.

Protecting Public Infrastructure

From roads to bridges, stormwater can devastate public infrastructure. Hurricane Harvey, for example, caused sinkholes and bank erosion in Houston, damaging critical infrastructure. Detention tanks alleviate these pressures, extending the lifespan of roads, utilities, and buildings.

Erosion Control

Unchecked water flow erodes landscapes and streambanks, destroying ecosystems and destabilizing soil. Stormwater detention tanks reduce water velocity, protecting both natural habitats and human-made environments.

Space Efficiency

Unlike retention ponds or basins, detention tanks require less space and can be installed underground, making them ideal for urban areas where land is scarce.

Adaptability to Climate Change

As extreme weather becomes more frequent, detention tanks offer a scalable solution to handle increased runoff. Their design can be adapted for both residential and industrial stormwater management needs.

The Hidden Costs of Inaction

When stormwater systems fail, the social and environmental consequences ripple through communities:

• Displacement of Vulnerable Populations: Flooding disproportionately affects low-income families who often live in flood-prone areas and lack resources for recovery.
• Waterborne Illnesses: Contaminated floodwaters spread diseases, endangering public health.
• Environmental Damage: Flooding causes erosion, destroys ecosystems, and pollutes water sources, creating long-term ecological harm.
• Economic Losses: The U.S. has experienced billions of dollars in flood-related damages annually, much of it preventable with better stormwater management systems.

Investing in stormwater best management practices isn’t just about infrastructure—it’s about safeguarding human lives and the environment.

Why Detention Tanks Outperform Traditional Stormwater Management Solutions

Traditional "gray" infrastructure like pipes and culverts was never designed to handle the extreme weather we face today. These systems funnel water quickly into rivers, often exacerbating flooding downstream.

Stormwater detention tanks offer a more adaptive and controlled modern solution:

• They control flow rates, preventing downstream flooding.
• They can be integrated with green infrastructure, such as rain gardens or permeable pavements, to further enhance sustainability.
• Unlike retention ponds, they optimize space by being installed underground, leaving valuable surface areas for parks, buildings, or roads.

A Case for Green Infrastructure Integration

Green infrastructure—like permeable pavements, rain gardens, and green roofs—complements stormwater detention tanks by reducing the volume of runoff entering the system. When used together, these solutions:

• Reduce urban heat islands.
• Improve air quality.
• Enhance biodiversity in urban environments.

Cities that combine green infrastructure with detention tanks, such as Brush Park in Detroit, achieve better outcomes, balancing urban growth with environmental stewardship.

Case Studies: Real-World Applications of Stormwater Detention Tanks

• Jacksonville IKEA, Florida: A stormwater detention system with 259,000 cubic feet of storage managed runoff efficiently, protecting valuable retail space from flooding.
• Cowes, Phillip Island, Australia: On-site detention (OSD) tanks reduced flooding and improved water quality in a densely populated area.
• Ellicott City, Maryland: Developers incorporated underground detention tanks to prevent future floods after the town experienced two catastrophic events in 2016 and 2018.

These examples highlight the adaptability and effectiveness of detention tanks in urban, residential, and commercial settings.

Social and Environmental Impact of Failed Stormwater Management

The consequences of failed stormwater management are deeply human. Families lose homes, workers lose jobs, and ecosystems are forever altered.

• Hurricane Maria (2017): Puerto Rico’s total loss of power and catastrophic infrastructure damage left communities in crisis for months, highlighting the importance of resilient systems.
• Detroit Floods (2021): Thousands of homes were damaged, and public infrastructure was left underwater. Many affected residents were low-income families with limited resources to recover.

What Can We Do?

• Invest in Modern Solutions: Detention tanks, retention tanks, and green infrastructure should be prioritized in urban planning.
• Close the Funding Gap: The $8 billion annual shortfall for stormwater infrastructure must be addressed through federal and state initiatives.
• Educate Communities: Public awareness campaigns can help individuals take steps to reduce runoff, such as installing rain barrels or maintaining green spaces.
• Incorporate Climate Projections: Stormwater systems must be designed to withstand the future intensity of storms, not just today’s challenges.

Tank Depot’s Call Out: The Time to Act is Now

Stormwater management is no longer just an engineering issue—it’s a human one. Behind every failed system are stories of families displaced, businesses shuttered, and ecosystems destroyed. The events of the last 15 years have shown us what happens when we underinvest in infrastructure: billions of dollars in damages, lives lost, and communities left to rebuild.

Stormwater detention tanks represent a lifeline. They’re cost-effective, scalable, and adaptable to urban and rural settings alike. When paired with green infrastructure, they provide a roadmap for sustainable, resilient cities.

At Tank Depot, we’re committed to helping you protect your community. Our comprehensive range of stormwater management solutions—from detention tanks to advanced filtration systems—empowers you to meet the challenges of a changing climate head-on.

Let’s create a safer future together. Contact us today to explore the best stormwater solutions for your needs.