Development of an Experimentally-Derived Clogging Prediction Method for Stormwater Infiltration Systems

(2004 – 2007)
Nilimini Siriwardene

Stormwater infiltration systems are recognised as a useful technique to meet stormwater management objectives of peak discharge control, pollutant removal and runoff volume reduction. This thesis examined their greatest limitation, clogging, by exploring one dimensional (1D) and two dimensional (2D) vertical flows through laboratory experiments, developing a clogging model and applying results for Australian cities.

Experimental data enabled an in-depth understanding of the transport of sediment particles in vertical flows through an infiltration system and the physical clogging process. The experiment was conducted on a gravel filter and soil beneath, testing constant and fluctuating water levels with different sediment flow concentrations. For 1D vertical flow experiments, it was discovered that a clogging layer developed between gravel and soil irrespective of flow regimes, but that the development of the clogging layer was slower if the water level was kept at a constant level. Verification of the model (in Aberdeen, Scotland), based on investigation of independent data sets, was successful. In 2D experiments it was found that the clogging layer developed at the base as well as the lower part of side walls, in contrast to common assumptions. Application of the 1D model to 2D fluctuating water level data gave good results. Long-term performance of various sizes of infiltration systems were studied for Australian climates by extrapolating findings of the 2D study. The thesis provided insights into clogging within stormwater infiltration systems, providing a useful tool for prediction.

Click here to read the abstract of this PhD – PDF (0.3MB)

Project Partner:
This research was supported by an ARC Discovery Grant.

Supervisors:
Prof Ana Deletic and Prof Tim Fletcher

Publication:
Siriwardene N.R. (2007) Development of an Experimentally-Derived Clogging Prediction Method for Stormwater Infiltration Systems. PhD Thesis, Department of Civil Engineering, Monash University.

Other Publications (link)

Link:
Non-Vegetated Filtration Systems/BiofiltersWSUD Technologies