Hulevesien varastoinnissa ja viivytyksessä hulevedet johdetaan suuriin säiliöihin, joista ne päästetään painovoimaisesti tai pumpulla pikkuhiljaa eteenpäin viemärijärjestelmiin tai purkupaikkaan.

Storm water tanks

Storm water tanks prevent floods caused by heavy rains

We cannot stop rain from falling, but it is possible to avoid floods caused by heavy rain. When storm water is stored and retained, water is fed into large tanks where it is gradually released by gravity or by pumping it into either the sewer system, or a discharge location. The volume of water remains under control, and floods are prevented.

During periods of heavy rain, the output connection begins to dam up and the water level in the tank rises. Water is collected in the tank in a controlled manner, and it can be gradually emptied into a discharge location. Water is suppressed by either a flow regulation chamber or pumping.

A retention tank is used for storm water when

  • the soil is too dense for storm water to infiltrate
  • extra storage capacity is required in addition to the existing storm water sewer
  • the groundwater is so high that storm water cannot infiltrate into the soil
Large sites

A durable system that is easy to maintain

Weholite storm water tanks consist of Weholite pipes, supplied in the desired length, and welded together either at the factory or the construction site. Installation is quick – all that is required on-site is to excavate the area, install the tank, and fill in the excavation. Storm water tanks are hermetically sealed, and they can be installed in groundwater areas or below the surface level of groundwater. The system is emptied by discharging into a gravity sewer or by pumping.


  • Enables rainwater to be monitored, purified and inspected
  • Suitable for retaining water, particularly in urban conditions where land area is very valuable: the space beneath asphalted areas can be used
  • Ability to build systems with very large storage capacities: tank diameters of up to 3 metres, lengths according to the client's needs
  • As opposed to pools, tanks can be installed out of sight and out of reach of children in order to guarantee safety.
Uponor storm water tank
Small properties

Retention tank for storm water on small properties

On construction projects it is important to design and implement the systems outside the building and the yard in such a way, that storm water does not cause problems for buildings or outdoor areas. Storm water requirements have changed in recent years. Several towns require runoff to be retained in urban areas before it can be fed into the municipal storm water drains. Uponor's retention tank is designed specifically for retaining runoff from the roofs and yard areas of small houses. Retention tanks slow the flow of storm water, and store water before it is fed into the municipal storm water drains.

Applications include small houses, semi-detached houses and small terraced houses. The tank's retention volume is 2,500 litres. The Uponor retention tank is a simple, reliable solution. The tank is low in height and can be installed below lawns or gardens.

Uponor supplies a wide range of solutions for managing storm water: pipes, chambers, infiltration cassettes, and tanks to complement the system.

Uponor Storm water retention tank
Collection of storm water

Rainwater collection tank

The Uponor rainwater collection tank enables you to store rainwater. This offers you a free, alternative source of water that you can use whenever you need it.

Thanks to the Uponor rainwater collection tank, you do not need to water your lawn, flowers and plants using drinking water. All you need, is a tank is installed underground, and all of the rainwater from the building's roof is fed into the tank. An overflow pipe ensures that the tank's water level never rises above the specified level. An added perk is, that you do not need to pay for sprinkler water, and you save on natural resources. Connect a pump to the tank to obtain your own – and, above all, free – source of water!
Uponor storm water tank for small properties

In addition to storm water tanks for large sites, we can custom-design:

  • Tailwater tanks
  • Chemical tanks
  • Overflow tanks
  • Septic tanks

We also custom-manufacture alkalisation plants, fire hydrants, slurry reception stations and more in accordance with design.

Contact us for more information or for a quote for a custom solution.

Weholite storm water tanks prevent floods

During heavy rain, floods and overloaded pipelines can be avoided using Weholite retention tanks. See Uponor's solution for managing large amounts of storm water.