Figure legends

Figure 1. Root intrusion through cracks and joints of sewer pipes as examples of sewer infiltration passage (Urbana Champaign Sanitary District, 2012)
Figure 2. Rainfall and sewer flow data (a) rainfall record from ISWS (b) sewer flow data from USGS sewage monitoring site in the period of April 17–August 3, 2009
Figure 3. Impulse response functions from the roof connection, sump pump, and leaky lateral models with the representative rainfall expressed as flow discharge per unit contribution area
Figure 4. Long term RDII responses of roof connection, sump pump, and leaky lateral using exceedance probability of three RDII responses per unit area in log scale in the period of April 17–July 16, 2009
Figure 5. Three RTK triangular hydrographs from 30 different model runs
Figure 6. Box plots of RTK solutions
Figure 7. Calibrated IRF and the best RTK results in the (a) calibration period (May 9, 2009 to June 7, 2009) and the (b) validation period (June 9, 2009 to July 8, 2009)
Figure 8. Residual plots of IRF and RTK methods for (a) calibration period and (b) validation period