Underground Detention and Infiltration Systems

Engineers typically choose between metal, plastic, and concrete underground detention systems by evaluating the specific needs of the project, including required storage volume, available footprint, cover depth, loading conditions, groundwater elevation, site layout, maintenance access, installation requirements, service life goals, and total installed cost.

Each material has advantages depending on the application. Corrugated metal pipe systems can be a cost-effective option for medium-to-large storage volumes and can offer flexible layouts, large diameters, deep burial capabilities, and efficient access for inspection and maintenance. Plastic chambers may be considered where shallow cover, modular layouts, or smaller storage volumes are needed. Concrete underground detention systems can be a strong option for projects that require high capacity, long-term durability, and are compatibility with heavy loading conditions.

The best choice is not always the lowest material cost. Engineers should consider the full project impact, including excavation limits, stone requirements, installation time, accessibility, long-term maintenance, and lifecycle performance.

Contech can help engineers compare underground detention options based on site-specific conditions and project goals, so the selected system meets hydraulic, structural, constructability, maintenance, and budget requirements.

Stormwater detention systems need pretreatment to keep sediment, trash, debris, and other pollutants from entering the storage system. Without pretreatment, these materials can accumulate inside the detention system, reduce available storage volume, clog outlet controls or infiltration surfaces, and increase long-term maintenance costs.

Pretreatment captures pollutants upstream before they reach the detention system. This helps preserve storage capacity, protect system components, and keep the system functioning as designed. It also makes maintenance easier because trash, sediment, and debris are collected in one accessible location rather than being spread throughout the detention system.

This is especially important for underground detention and infiltration systems, where accumulated material can be more difficult to access and remove. By concentrating maintenance in a dedicated pretreatment structure, owners can simplify inspection, reduce cleanout complexity, and better protect the long-term performance of the detention system.

Contech can help engineers evaluate pretreatment options that fit the site, regulatory requirements, maintenance needs, and overall stormwater design.

Detaining stormwater underground helps manage runoff while preserving valuable surface space for parking, buildings, landscaping, pedestrian areas, or other site uses. This can be especially beneficial on commercial, industrial, institutional, and urban sites where land is limited and every square foot matters.

Underground detention systems can also improve site flexibility by allowing stormwater storage to be placed beneath paved areas, drive aisles, parking lots, or open space. This can help engineers meet stormwater requirements without dedicating large surface areas to ponds or basins.

Another benefit is reduced exposure at the surface. Underground systems can help minimize open-water safety concerns, reduce mosquito habitat, and limit the need for large fenced or landscaped detention areas. They can also support a cleaner, more usable site layout.

From a design standpoint, underground detention systems can be configured to meet site-specific storage, footprint, depth, loading, and outlet control requirements. When properly designed with access and pretreatment, they can also support long-term inspection and maintenance.

Contech can help engineers evaluate underground detention options based on required storage volume, available footprint, cover depth, groundwater conditions, traffic loading, maintenance access, and total installed cost.