design of 6th well pump

Hello Indu, 

You can model the bore well as reservoir with water elevation of well as Reservoir elevation so that would become your HGL. 

Here is information about modeling well and submersible pump for your reference. 

Modeling a submersible pump

How do you want to model this submersible pump as constant speed pump or variable speed pump?

How to consider the drawdown of well and decide pump curve based on that is explained below, please go through it. 

Accounting for well drawdown

You can model flow control valves as FCV elements as usual. 

Hello Indu,

How is this entire system setup? Usually a single bore well is associated with a small submersible pump. In your system I am guessing that each bore well has its own pump. Is that correct?

If that assumption is correct, then are those pumps connecting to a common header? Is your 6th bore well is series of the other 5 bore wells?

As Sushma suggested you can simply consider the bore well as a reservoir element and the elevation set as per the water level in the bore well. However, please consider the draw down into the elevation you are using to get a realistic estimate.

indu appan said:

Also  combination of bores results in different head loss in the system. How can I go about it?

Can you elaborate on this? Is this because the bores are in series connected to a common header or are the pumps in parallel? 

To model your 6th bore well pump you would have to consider the following;

1. Pump head and flow at 6th bore well incorporating the well draw down

2. System head curve considering the combination of pumps you are using. See this article for reference: Understanding System Head Curves

3. Accounting for the maximum headloss conditions

It would help us understand your query if you can share some schematic on how the system is setup and what you are trying to achieve.