TY - JOUR

T1 - Physically based modeling of stormwater pipe leakage in an urban catchment

AU - Peche, Aaron

AU - Graf, Thomas

AU - Fuchs, Lothar

AU - Neuweiler, Insa

N1 - Funding information: We want to thank the associate editor and the three anonymous reviewers for investing the time to give a thorough and productive feedback. The feedback helped inprove the manuscript significantly. We thank Bora Shehu for providing precipitation data, and Yibo Zhu, Robert Sämann and Simon Berkhahn for discussion. The research is being conducted within the BMBF funded research project EVUS (EVUS – Real-Time Prediction of Pluvial Floods and Induced Water Contamination in Urban Areas) [BMBF, 03G0846A].

PY - 2019/6

Y1 - 2019/6

N2 - In urban stormwater pipe networks, pipe leakage may lead to reduction of groundwater recharge, to significant reduction of groundwater levels, and to subsurface contamination. In the present study, stormwater pipe leakage is simulated in a case study representing an urban catchment using the coupled groundwater-pipe network flow model OGS-HE. This model includes pipe flow, variably saturated subsurface flow and exchange fluxes to and from leaky pipes. The study area is a typical northern German urban catchment with a stormwater pipe network which is located partly below and above groundwater. The successful calibration of a groundwater model is shown. Based on the calibrated groundwater model, stormwater pipe leakage for pipe networks of different ages and different pipe defect sizes is investigated for dry-weather flow conditions and rainfall conditions. It is shown that standard defects with a size of 10-4 m2 per m pipe can result in a groundwater infiltration into the leaky pipe network, which is in the order of annual groundwater recharge. The same standard defect size leads to a reduction of local groundwater levels by several meters. Rain events of increasing return period reduce groundwater infiltration into leaky pipes and increase stormwater exfiltration from leaky pipes, while the temporal distribution of a rain event has no effect on stormwater leakage.

AB - In urban stormwater pipe networks, pipe leakage may lead to reduction of groundwater recharge, to significant reduction of groundwater levels, and to subsurface contamination. In the present study, stormwater pipe leakage is simulated in a case study representing an urban catchment using the coupled groundwater-pipe network flow model OGS-HE. This model includes pipe flow, variably saturated subsurface flow and exchange fluxes to and from leaky pipes. The study area is a typical northern German urban catchment with a stormwater pipe network which is located partly below and above groundwater. The successful calibration of a groundwater model is shown. Based on the calibrated groundwater model, stormwater pipe leakage for pipe networks of different ages and different pipe defect sizes is investigated for dry-weather flow conditions and rainfall conditions. It is shown that standard defects with a size of 10-4 m2 per m pipe can result in a groundwater infiltration into the leaky pipe network, which is in the order of annual groundwater recharge. The same standard defect size leads to a reduction of local groundwater levels by several meters. Rain events of increasing return period reduce groundwater infiltration into leaky pipes and increase stormwater exfiltration from leaky pipes, while the temporal distribution of a rain event has no effect on stormwater leakage.

KW - Catchment scale

KW - HYSTEM-EXTRAN

KW - OpenGeoSys

KW - Stormwater pipe leakage

KW - Urban groundwater

UR - http://www.scopus.com/inward/record.url?scp=85063979552&partnerID=8YFLogxK

U2 - 10.1016/j.jhydrol.2019.03.016

DO - 10.1016/j.jhydrol.2019.03.016

M3 - Article

AN - SCOPUS:85063979552

VL - 573

SP - 778

EP - 793

JO - Journal of hydrology

JF - Journal of hydrology

SN - 0022-1694

ER -