Simulation of a Water Distribution Network with Key Performance Indicators for Spatio-Temporal Analysis and Operation of Highly Stressed Water Infrastructure

Abstract

An annual and lumped water balance assessment of a water distribution network is recommended by the International Water Association as a first step and prerequisite for improving the performance of the network by minimizing real/physical water losses, burst incidents, water theft, nonrevenue water, and energy consumption, among others. The current work suggests a modeling approach for developing the water balance of a network spatio-temporarily, in hour time-scale and neighborhood granularity. It exploits already established key performance indicators and introduces some new ones to highlight the potential in improving the management of a water distribution network when having a detailed spatio-temporal supervision, especially when the spatial and temporal conditions are variable. The methodology is applied in a seasonally touristic and hilly case study. Additionally, a pressure management scheme is applied to further exploit the potential of such a toolkit. For the investigated case study, the town of Skiathos, the annual real losses are estimated equal to 50.9–52.2% of the system input volume, while apparent losses are estimated to be about 5.6–6.6%. Losses depict intense seasonal variability. Real losses range from 38.8–39.6% in summer months to 63.3–64.7% in winter months, while apparent losses range from 8.4–9.3% in summer to 1.3–2.5% in winter. Annual water theft is estimated to be at least 3.6% of system input volume. Spatial variability, which is linked to the elevation and the different urban land uses is proven to play a significant role in the neighborhoods’ water balances and various key performance indicators are suggested and applied for the pressure control scheme. The annual potential savings due to the applied scheme rise up to 51,300 m3 for leakage and 53,730 m3 for pressure-driven demand.

Insights on the Water–Energy–Food Nexus

“…Specifically, the residual service lives of decommissioned water tanks should be assessed [22] to better manage water supply systems. As drinking water supply systems are vulnerable both spatially and temporally, it is important to use key performance indicators (such as leakage reduction, pressure-driven demand reduction and energy and economic savings) [23] for the improvement of water distribution system management. High operating pressure is responsible for high leakage rates, while low operating pressure increases water age.…”

“…Key performance indicators to be used for the improvement of water distribution system management with detailed spatio-temporal supervision are introduced in [23]. The results showed that losses depict intense seasonal variability, while spatial variability, which is linked to the elevation and the different urban land uses, is proven to play a significant role in the neighborhoods' water balances.…”

Water resources planning under climate and economic changes in Skiathos island, Aegean

“…The model attempts to show the possible evolution of water demand, so the demand-driven pressures were included in the simulation, i.e., billed authorized consumption (as metered from WUS) and apparent losses (theft and metering inaccuracies). The components of the IWA water balance table specifically for the case of Skiathos were recently described by Kofinas et al (2020), so the respective seasonal estimations were used in the model per quarter (as percentage increment of consumption): 5.57% for January-March, 8.8% for April-June, 17.05% for July-September and 23.61% for October-December. The real losses are also very high, but since there were no available data on the physical water availability, in order to simulate the hydrological water balance (i.e., the actual supply pressures), the analysis discusses the demand (human-driven) side.…”

“…The main settlement is the city of Skiathos (4,992 habitants), served by a pipeline network, suffering from losses and leakages (around 60% in total). The annual real losses are approximately 51%, the annual apparent losses 6%, and the annual water theft is at least 3.6% of the system input volume, according to Kofinas et al (2020).…”

The Impact of Possible Mercury Source-Point Contamination in the Coastal Area of Skiathos Island

“…The permanent residents are about 6000, while the island population grows rapidly during the tourist season lasting from April to early October [21]. The water demand presents high seasonal variability peaking in August when water pumping shows an increase often exceeding 130% of the winter minimum, indicating a link between touristic activity and the water demand [22]. The entire island water network is served by one drilled well, supported by a smaller well when required, which results in serious water supply issues for the island.…”