**2. Methodology**

### *2.1. Study Area Description*

The study area for our current work is at the University of Kashmir, located in Hazratbal, Srinagar, Jammu and Kashmir, India. It is a residential campus comprising academic blocks, administrative blocks, hostels, a medical unit, a cafeteria, and staff quarters. It has a residential and floating population of 5324 and 1050, respectively, for the Naseem Bagh Campus and 8066 and 1720, respectively, for the Hazratbal Campus.

### *2.2. Methodological Approach*

A quantitative research approach was employed to arrive at the optimal design of the WDS for the University of Kashmir by using various software. A literature review related to the work was carried out, and the related standard books and codes were consulted. A preliminary survey of the study area was followed by a division of the study area into two parts, with separate WDNs for each of them (the Hazratbal campus and the Naseem Bagh campus). The water source for the networks is the groundwater reserve within the campus, which is pumped by intermittently operating pumps into the overhead water tanks.

### *2.3. Methods of Data Collection*

The quantitative data of the existing population at various academic blocks, hostels, family quarters, and administrative blocks was obtained. The maximum depth of water in the bore wells below ground level is 10 m. In addition, the campus plan of the study area was obtained. The data availability was facilitated by the engineering wing of the UOK. Elevation data was obtained using Google Earth Pro.

### *2.4. Methods of Analysis*

#### 2.4.1. Evaluation of the EPANET 2.2 Input Parameters

A dead-end type of distribution system was provided for both parts of the campus. The population forecast for the design period of 30 years, with a constant increase of 5% per decade in both residential as well as the floating population was carried out [15,16]. The values of ADD for both parts of the network were evaluated using water demand as 135 lpcd for the residential population and 45 lpcd for the floating population [17]. The MDD was evaluated using a peak factor of '1.8' [18], and a peak factor of '3' was used to calculate the MHD from the AHD [18]. Provisions to meet the fire demand were kept as per Indian standards [19]. The base demand multiplier equals the coincident draft in litres per person per minute (Table 1). Two different demand patterns were used for the network nodes: one for the hostels and quarters (p1), and the other for academic buildings

and administrative blocks (p2). The capacity of the storage tank was evaluated by the mass curve analysis for both parts of the network. The discharge to be provided by the pump was worked out by considering 12 h of pumping per day. The staging height of the tank above ground level was selected after iterations to successfully run the software and achieve standard pressure heads at the nodes. The economical diameter of the rising main was obtained using Dupit's expression. The pressure head developed by the pump has to be equal to the sum of the delivery head, suction head, and frictional head loss in the rising main. The input power required to run the pump equals ( ωQH/n), and the efficiency of the pump (n) was taken as 75%. Energy required for a 12-hour per-day operation of the pump was evaluated to arrive at the cost of the electrical energy at Rs 5 per unit per day. The design flow rate of the pump was equal to the MHD in litres per minute (Table 2). After entering the EPANET 2.2 input data [20] and successfully running the software, a hydraulic modeling of the networks was carried out. Simple controls (obtained after iterations to successfully run the software and achieve standard pressure heads at the nodes), as given in Table 3, were used to perform the hydraulic analysis.


**Table 1.** Demand calculations for WDS Parts I and II.

**Table 2.** Storage tank and pump characteristics.



**Table 3.** Simple control for WDS Parts (I, II).

2.4.2. Evaluation of the Technical Performance Indices (TPIs)

The behavior of the nodes and pipes of the WDS can be evaluated using the TPIs (technical performance indices), which are indicative of the performance of the network with respect to the hydraulic parameters such as pressure head and flow. Two types of TPIs are used: TPI pressure [14] and TPI velocity [14]. The TPI values range from 0 to 1, '0' for poor service, and '1' for efficient service. The TPI values for both parts of the network were evaluated and compared with the standard values as follows:

$$\text{TPI}\_{\text{pressure}} = \Sigma \text{ (Q}\_{\text{i}} \times \text{TPI}\_{\text{i}}\text{)}\Sigma \text{ Q}\_{\text{i}}\text{'} $$

where Qi = nodal demand and (i) iterates over all the nodes of the network.

TPIi = 0, Pi < Pmin = 1, Pmin < Pi < Pma = 1 − {(Pi − Pmax)/(Pmax − Pmin)}, Pmax < Pi < 100 = 0, Pi > 100

Here, Pi = prevailing pressure head at the node, Pmin = 17 m, Pmax = 70 m, and TPIi = TPI. For the node i:

$$\text{TPI}\_{\text{velocity}} = \Sigma(\mathbf{Q}\_{\text{j}} \times \text{TPI}\_{\text{j}}) \ell \Sigma \mathbf{Q}\_{\text{j}}.$$

where Qj = flow in pipe (j), and (j) iterates over all the pipes of the network.

TPIj = 0, Vi < Vmin = (Vi − Vmin)/(Vmean − Vmin), Vmin < Vi < Vmean = (Vi − Vmax)/(Vmean − Vmax), Vmean < Vi < Vmax = 0, Vi > Vmax

Here, Vi = prevailing flow velocity in pipe j, Vmin = 0.2 m/s, Vmax = 3 m/s, and TPIj = TPI for the pipe j, Vmean = (Vmin + Vmax)/2.

#### 2.4.3. Input Parameters for the Jal-Tantra Web System

The input data for nodes (elevations, base demand, and minimum pressures) and pipes (start nodes, end nodes, length, and roughness) is entered into the Jal-Tantra system. Commercially available pipe diameters and their cost per unit length according to the prevailing market rates are also provided. The input data is given in Tables 4 and 5.

### **Table 4.** General input data.


**Table 5.** Commercial pipe data.


2.4.4. Optimization of the Hydraulic Model
