Controlling rainwater discharge from a large-scale sports facility based on rain gauge data

In 2021, Opole completed an investment in the redevelopment of the areas around the Cieplak Hall and “Okrąglak”. The modernized hall has become part of the Opole Sports Park. The investment included a multifunctional field, a running track, mats for combat sports and a climbing wall. The outdoor redevelopment included the creation of a soccer field, a multipurpose field to be used as an ice rink in winter, a skate park and a playground.


Modernizing the area also includes constructing a new stormwater drainage network to drain the entire infrastructure and integrate it into the existing city infrastructure.


The technical conditions issued to the developer for this project required retention of rainwater and controlled discharge into the sewer system after rainfall ceased.


RETENCJAPL has supplied and commissioned equipment to control rainwater runoff as described in the technical conditions.



  • The requirements given to the task developer regarding the possibility of discharging rainwater into the city’s stormwater drainage system specified exactly when and how the retention tanks could be emptied. The document, issued by the City of Opole, required that in the case of a rainstorm with a duration of 15 minutes and an intensity of 150 l/s/ha, rainwater runoff should be limited to zero for at least 30 minutes. After this time, the allowed discharge is limited to 5 l/s from each hectare of drainage area.



  • LUFFT WS100 radar rain gauge and OTT netDL500 data logger were used to complete the task. The rain gauge used is a completely maintenance-free device, guaranteeing measurement with sufficient accuracy throughout the year. Measurement data from the rain gauge is processed by the recorder, which controls the operation of the gate valve after the occurrence of programmed conditions. In addition, all rainfall data is sent to the RainBrain app and available for analysis for the city’s stormwater drainage managers. 



  • Implementation of the provisions contained in the technical requirements regarding the detention time of rainwater after the occurrence of heavy rain was possible only through the installation of a rain gauge with a device analyzing the measurement data. Thanks to this approach, the investor is assured that the discharge of rainwater from the upgraded site is carried out in accordance with the recommendations of the City Council. Delaying the outflow of rainwater from the area of the sports facility allows optimal use of the capacity of the existing municipal sewage system without the need for its reconstruction. The maximum outflow from the upgraded catchment goes into the sewer system with a 30-minute delay, which prevents overloading and the occurrence of local flooding.