Simulating equity in intermittent water supply using pressure sustaining valve in EPANET 2.2

ABSTRACT

Intermittent water supply (IWS) system refers to a system of water supply that delivers water to consumers for a fixed period (2 hours, 3 hours, 4 hours, etc.), which is less than 24 hours a day. Literature shows that the issue of inequity has been a major concern in IWS. In this study, an attempt has been made to simulate a new way of operation of IWS by including volume of nodal demand, such that, the flow becomes uncontrolled volume-driven pressure dependent. The novel methodology presented makes use of a pressure sustaining valve (PSV), which rearranges the flow within the network, thus improving the equity in IWS. Further, the study aims to quantify the equity in IWS by formulating two different approaches: uncontrolled pressure-dependent analysis (UC-PDA) and uncontrolled volume-driven pressure-dependent analysis (UC-VDPDA). Both approaches have been applied to three different water distribution networks. Results show that UC-VDPDA provides a more equitable supply in terms of getting a fair share of water to the consumers.

KEYWORDS:

• Intermittent water supply
• uncontrolled pressure-dependent analysis
• uncontrolled volume-driven pressure-dependent analysis
• water distribution networks
• equity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Some or all data, models or codes that support the findings of the study are available from the corresponding author upon reasonable request.

Important Notation

AP	=	Artificial pipe
AR	=	Artificial reservoir
AT	=	Artificial tank
CV	=	Check valve
DDA	=	Demand-driven analysis
DN	=	Demand node
FN	=	Fictitious node
IWS	=	Intermittent water supply
PDA	=	Pressure-dependent analysis
PSV	=	Pressure-sustaining valve
$Q_j$	=	Demand at node j
$Q_j^{a}vai$	=	Actual available outflow at node j
$Q_j^{r}eq$	=	Required demand at node j
SN	=	Source node
UC-PDA	=	Uncontrolled pressure-dependent analysis
UC-VDPDA	=	Uncontrolled volume-driven pressure-dependent analysis
VDA	=	Volume-driven analysis