The Design Of Potable Water Supply System For Institutional Setting
[A CASE STUDY OF KWARA STATE POLYTECHNIC PERMANENT SITE]

CHAPTER THREE
3. METHODOLOGY  
The design of potable water supply system for institutional setting (a case study of Kwara State Polytechnic Permanent site)was carried out using the following research methods:
1.    Sourcing the plan layout of Kwara State Polytechnic Permanent Site from works department and using it to deduce the Pipe layout
2.    Sourcing the population to determine the water demand for the design year of Kwara State Polytechnic Permanent Site which consists of administrative blocks, hostel, convenient room, mini mart and so on.
3.    Designing the water distribution system using HARDY CROSS METHOD for water distribution network design.
3.1 PLAN LAYOUT
The layout of the campus site, topography etc. greatly affected the layout and design of the distribution system. The existing population expected future population, commercial and industrial present and future water requirements all were considered in the layout and design of the distribution system. The main work in the distribution system design was to determine the sizes of the distribution pipes which will be capable to carry the required quantity of water at the desired pressure.  
For the efficient design of distribution system the following steps were followed:  
1.    Surveys and maps ofKwara State Polytechnic Ilorin: 
Reconnaissance survey: this is the preliminary research such as visitation to Kwara State Polytechnic permanent site for the acquisition of data and information regarding the topography, the layout of structures, position of roads, streets, lanes, commercial locality, etc.
2.    Tentative layout: 
Showing position of treatment plant distribution, mains distribution, balancing reservoir, hydrants etc. were located.  
3.2 Population
Kwara State Polytechnic Ilorin Permanent Site campus
1.    Population density: 30,000 inhabitant
2.    Change in population: It is negligible as students are being admitted while some are being graduated
The design area is divided into parts for easy design and calculations.
3.3 Design of pipe lines:  
It consists of the following norms-  
1.    Discharge in pipe lines: Based on the density of population and other requirements, the pipes will be designed for maximum demand. 
2.    Calculation of pipe diameters: 
Flow velocity remains in pipes between 0.6 m/sec to 3 m/sec. The head loss was calculated using Hardy Cross Method.
The AWWA’s Manual of Water Supply Practices (M-31) states that the recommended design is to have the major load center located between the pumping station and an elevated storage tank of sufficient capacity. This system is the most cost-effective design from a capital cost and operating cost standpoint. All those individuals that are involved in the planning, designing, and evaluating community water systems need to keep this concept in mind. It is not a rule but it is a good practical guide.
3.3.1    Design Parameters:
    The design of a network system is based on the certain features that affect the shape and size of pipes constituting the distribution network. Some of these influencing factors are:
1.    Topography of the study area
2.    Population (Current & Forecasted as given above)
3.    Distribution of land into zones
4.    Water demand in Each Zones

Where:
Kis resistance co-efficient
F is co-efficient of friction
L is length of the pipe
D diameter of the pipes