Improving the understanding of on-site stormwater detention performances

ABSTRACT

On-site Stormwater Detention has been used around the world to reduce stormwater peak flow at lot scale. However, few studies have evaluated its performance as well as its hydrological and hydraulic parameters on a real scale. To evaluate these variables, two OSDs were monitored in Belo Horizonte/Brazil. Based on the analysis of monitoring data, it was observed that: (i) the OSDs average efficiencies in peak flow damping were higher than 50%; (ii) the storage volume per catchment area was close to 25 L/m²; (iii) the short tubes discharge coefficients were approximately 0.90 and; (iv) the shape of inflow hydrographs were similar to hyetographs. The use of the Unit Hydrograph Modified Rational Method properly represented the rain-runoff transformation. The findings could be used in OSD design to determine the inlet hydrograph, to pre-sizing the storage volume based on contribution area and to use the proper discharge coefficient value for outlet device.

KEYWORDS:

• Monitoring
• source control techniques
• urban drainage
• on-site stormwater detention

Acknowledgements

The authors thank the Universidade Federal de Minas Gerais, the Belo Horizonte Municipality, CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico (Chamada Universal – MCTI/CNPq Nº 14/2014), FAPEMIG – Fundação de Amparo à Pesquisa do Estado de Minas Gerais and CAPES – Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Finance Code 001) for their financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.