Rainstore3 is a modular stackable underground water/liquid containment system. It is installed subsurface to be used as detention basins and retention harvesting systems. Made from 100% recycled plastic, units come preassembled for easy drop-in-installation.

Rainstore3 is a solution for stormwater retention and detention as well as other applications requiring liquid storage. Water will percolate through the ground or covering and can either run through Rainstrore3 at a controlled rate or be stored for later use. Common applications include:

• Underground Detention Basin
• Retention/Harvesting Systems
• Water/Rain Gardens
• Green Roofs
• Sports Field Drainage
• Downspout Catch Basins
• Utility Liquid Battery Storage

Please see our Rainstore3 Estimator for product cost.

Rainstore3, arrives pre-assembled, for easy installation. It is modular and stackable so can be installed in a wide range of depths, maximizing the capacity of water storage.

Stormwater management is anything designed to mitigate the adverse effects of stormwater such as flooding, mud, rutting, pooling and general lack of drainage. All Invisible Structures products are designed to address these issues.

Underground detention systems include any structure or vessel designed to store rainwater or other liquid beneath the surface of the ground. A primary function of the vessel is stormwater management. Rainwater can be captured and fed back into the Earth to replenish groundwater or collected and harvested for future use. Storing water underground provides additional security as well. Examples of underground detention systems include arched chambers and plastic modular systems such as Rainstore3.

Rainwater Collection Systems include any vessel, tank or other basin that is designed to collect and store excess rainwater. Examples of these are barrels, concrete storage tanks, arched chambers, detention basins and plastic modular systems – such as Rainstore3. Reasons to collect excess stormwater vary from flood prevention to harvesting for the purpose of reuse. The efficacy of these systems differ based on size and design.

Rain barrels and concrete storage tanks are limited in their capacity because of their impervious walls, whereas arched chambers, detention basins, and plastic modular systems have unlimited capacity. Arched chambers and plastic modular systems have the advantage of storing water underground, allowing for usable space such as parking lots or green spaces on top.

Only Rainstore3 is strong enough to support the weight of structures such as a parking garage or small building.

There are several reasons to use a rainwater collection system. In areas with heavy rainfall where drainage is an issue, these systems can help mitigate the problems caused by flooding. All climates, including arid, can benefit by capturing rainfall and harvesting the water for reuse. Reusing water can save money and provide environmental benefits.

Another advantage of underground rainwater collection systems, not designed for harvesting, is that they can replenish the groundwater. Water shortages and the decrease in our ground water are among the planet’s biggest environmental concerns today.

There are several different types of Rainwater Collection systems. These include rain barrels, concrete storage tanks, arch chambers, milkcrate systems, and other plastic modular systems – such as Rainstore3. These different systems vary in size, cost, ease of installation and water storage/void capacity.

Rain barrels are the least expensive and do not require professional installation. Their capacity is limited by the size of the barrel. Concrete storage tanks are moderate in cost, also limited by their tank size, and require professional installation.

Arch chambers require a sizable installation area and a considerable amount of gravel fill which can be expensive. The void space is 40 – 50%. Milkcrate systems are mid-range in price but require complex assembly, which can add to the cost of labor. Their capacity is unlimited.

Modular plastic storage systems tend to be the highest initial cost but installation is relatively simple. Their capacity is also unlimited. Another benefit to plastic modular systems is the high void capacity and strength – Rainstore3 exceeds H-20 loading.

Rainstore3 exceeds H-20 loading allowing it to support vehicular traffic, lightweight buildings or greenspace. Please see our H-20/Hs-20 Guide for more information.

Rainstore3 is 94% void space. A single unit holds almost 25 gallons, which means each cubic meter is capable of holding up to 250 gallons.

Rainwater collection systems are used for either water detention or water harvesting. Either method is an effective way to control stormwater for flood prevention. For reuse, water harvesting is required from an impervious vessel or storage basin. Harvested water can be used as gray water, for agricultural purposes or can be purified and used as potable water.

Water detention basins allow water to seep back into the ground recharging the ground water. The depletion of ground water has become one of the biggest environmental concerns our planet is facing.

All collection systems require some minimal maintenance in order to maintain optimal functionality.

The amount of rainwater which can be collected varies by the type and size of the collection system used. Rain barrels typically hold 50 – 55 gallons per barrel. A rainfall of ½” on a 1,000 sq. ft. roof will fill one barrel. Concrete and plastic storage tanks range in size from 250 gallons to 15,000 gallons.

Arch chambers, milkcrate and plastic modular systems are only limited by the length, width and depth of the area as well as the void space of the system. For example, arch chambers provide only 40 – 50% space for water whereas Rainstore3 provides 96%. Therefore, each 1 meter piece of Rainstore3 holds up to 25 gallons, even though it’s only 4” high. At the maximum depth of almost 8’, 24 units of stacked Rainstore3 can hold almost 600 gallons of water in a single stack.

Rainstore3 comes in preassembled custom height stacks that can be unloaded and dropped directly into the job site. Installation is fast and easy. For additional details please see the Rainstore3 Installation Guide.

Inlet and outlet pipes can be attached to Rainstore3 by forming a “boot” with the fabric or liner and securing it with a hose clamp.

A minimum of 12” of compacted road base and a geogrid layer is required above the Rainstore3 chambers.

Rainstore3 is wrapped in a geotextile fabric or PVC liner so soil and vegetation are unable to penetrate the chamber.

Adding maintenance ports during installation allows Rainstore3 to be inspected after the installation is complete. Please see the Rainstore3 Maintenance Guide for Details.

Silt buildup can be prevented by using proper pre-filtration, such as catch basins or sediment filters. Using Rainstore3 in conjunction with Grasspave2 or Gravelpave2 can eliminate the need for any filtration systems as the water would be filtered naturally through bioremediation.