Quantification of energy losses at a surcharging manhole

Hydraulic models of sewer systems are commonly used to predict the risk of urban looding. However, suitable calibration datasets in lood conditions are scarce. The quantiication of energy losses within manhole structures is a current source of uncertainty within such models. To address this gap, a scaled physical manhole model is used to quantify hydraulic energy losses during surcharging and non-surcharging conditions. Two diferent novel conigurations were tested; (1) With and without the presence of a manhole lid; (2) With and without the presence of a shallow low on the surface. Results showed that total head losses were found to increase in surcharging conditions. The presence of the lid also marginally increased total head losses. The datasets are used to assess the performance of a numerical urban lood model (SIPSON) and comparisons highlighted that SIPSON tends to overestimate energy losses in surcharging conditions.