Perses is a software program designed to stochastically evaluate the reliability of water distribution networks into the future under changing environmental conditions, repair scenarios, and preventative maintenance scenarios. Pipe and pump reliability analyses considering environmental conditions are used to develop an exposure-based hardware failure assessment. Consequential water outages are modeled using distribution network data and EPANET software.
Distribution network data including demands; pipe types, locations, and elevations; tank and reservoir levels; pump locations and curves. This information will output relevant results based on criticalities and hydraulic properties of the specific network.
Ages of pumps and pipes
Cooling reduction of temperature rise of motors and electronics
Historical and future temperatures based on an ensemble of
Global Climate Models
Heat degradation equations
Ranges of parameters in degradation equations
Perses projects pump and pipe failures over time and under different climate scenarios, along with the demand node outages which occur due to the locations of the component failures and hydraulics of the network.
Perses also helps explore failure outcomes under different repair time and preventative maintenance scenarios.
The likely percentage change in failures from projections can inform capital improvement and maintenance planning.
By 2099 under hotter futures characterized by General Circulation Models, there is projected to be 5-8% more pump failures, 13-50% more iron pipe failures, and 5-21% more PVC pipe failures (RCP 4.5-8.5) than a baseline recent historical temperature profile. Service outages, which constitute inadequate pressure for domestic and commercial use, are projected to increase by up to 3% above the baseline by 2099.
To evaluate how well preventative maintenance and fast repair times could mitigate outages, we compare the percent of additional outages from climate change that were offset from implementing three independent possible adaptation strategies: (1) improved preventative maintenance at 50% above mid-levels, (2) improved repair times at 50% above mid-levels (i.e., 88 and 8 hours respectively), and (3) both improved preventative maintenance and repair times 50% above mid-levels.
An exploration of the mitigation potential of adaptation strategies within the model shows that improved preventative maintenance and repair times are capable of offsetting 100% of the additional failures from climate change and that improvements in repair times offset the most outages.
Learn more about how Perses can help identify effective strategies for offsetting future failures.