Assessment of LID practices for restoring pre-development runoff regime in an urbanized catchment in southern Finland

Abstract

This study quantifies the effects of common stormwater management techniques on urban runoff generation. Simulated flow rates for different low impact development (LID) scenarios were compared with observed flow rates during different urban construction phases in a catchment (12.3 ha) that was developed from natural forest to residential area over a monitoring period of five years. The Stormwater Management Model (SWMM) was calibrated and validated against the observed flow rates in the fully developed catchment conditions, and it was then applied to parameterize the LID measures and produce scenarios of their hydrological impacts. The results from the LID scenarios were compared with the observed flow rates in the pre-development and the partially developed catchment conditions. The results show that LID controls reduce urban runoff towards the flow conditions in the partially developed catchment, but the reduction effect diminishes during large rainfall events. The hydrographs with LID are still clearly different from the observed pre-development levels. Although the full restoration of pre-development flow conditions was not feasible, a combination of several measures controlling both volumes and retention times of storm runoff appeared to be effective for managing the stormwater runoff and mitigating the negative impacts of urban development.

Future Scenarios Modeling of Urban Stormwater Management Response to Impacts of Climate Change and Urbanization

“…Ahiablame and Shakya reported that LID measures can be used to attenuate flood risks in an urban watershed . Guan et al reported that LID measures appeared to be effective in controlling flow quantity and water quality of runoff and mitigating the negative impacts of rapid urbanization …”

Simulation of the cumulative hydrological response to green infrastructure

“…Guan et al . [] reported total runoff volume reduction in the range of 24.5%–78.3% for various hypothetical low impact development practices placed on an urban catchment. Walsh et al .…”

“…Green infrastructure is designed to mitigate storm water impacts, and its success at doing so has been reported in multiple studies [e.g., Roseen et al ., ; Damodaram and Zechman , ; Askarizadeh et al ., ; Guan et al ., ; Winston et al ., ]. Although the effectiveness of storm water management practices has been assessed for different climates and designs, there is a limited knowledge base for how these solutions impact, separately or jointly, catchment‐scale hydrology [ Bell et al ., ].…”

“…For example, Guan et al . [] showed that the combination of several green technologies led to changes in the runoff regime in a 12.3 ha medium‐density residential area in Finland; however, these practices were not able to fully restore predevelopment hydrological conditions. Their model was calibrated with data from six events using existing conditions only (no green infrastructure).…”

Storm runoff response to rainfall pattern, magnitude and urbanization in a developing urban catchment

“…The EPA SWMM was selected to perform the hydrological analysis in the studied urban catchment. SWMM is a widely used urban hydrological model for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas (Denault et al, 2006;Jang et al, 2007;Meierdiercks et al, 2010;Krebs et al, 2014;Guan et al, 2015a;Guan et al, 2015b). SWMM describes the urban catchment as a drainage network and a set of subcatchments connected to the network.…”