Design and Simulation of a Water Distribution System of a Residential Area using EPANET

UNIversity of the philippines - dilimanDesign and Simulation of a Water Distribution System of a Residential Area using EPANETCE 112: Water Resources EngineeringLicerio, Arthel Rae T.2010-32196

Submitted to:Prof. Peter Paul Castro

May 26, 2015

I. IntroductionDeveloping and planning an efficient water distribution system is important for communities. Water has a lot of use whether it is commercial, industrial, agricultural or domestic. It is essential to a citys growth and it depends on how efficient water can be delivered. In simulating a water distribution system, the EPANET is the most commonly used tool. EPANET is a public-domain modelling software developed by the Environmental Protection Agency of the United States in 1993. EPANET is a research tool that improves understanding of the movement and fate of drinking-water constituents within distribution systems (EPANET). In this study, a water distribution system must be designed. It specifically aims to: Design a water distribution system for a residential area. The residential area shall be a subdivision consisting of 800 households and having a nearby river as a water source. Simulate the water distribution of the area using EPANET. Determine the pressure in the nodes and the velocity in the pipes of the design and check whether it satisfies code provisions.

II. MethodologyFor the modelling and simulation, EPANET 2.0 will be used. It will track the flow of water, the velocity in pipes, the pressure at each nodes and height of water in tanks. The layout of the subdivision was first developed in the software as can be seen below.

Figure 1. Layout of the SubdivisionThe schematics of the subdivision show one reservoir, one pump, 18 water tanks and 288 end nodes. Each node represents 3 houses/households. There are 18 streets in the subdivision. This system is idealized as the system 3 on Figure 2. The total households is changed to 864 households, the increase was due only to symmetry and aesthetics. A street (above water mains) is approx. 1000 feet. The demand for each node (3 households) was determined to be 8.0 x 10-4 cubic feet per second. This was obtained from the average day demand and converting it to proper units.

Figure 2. System 3 for each nodeSince the reservoir is assumed to be on the same elevation as the nodes and pipes, a pump used to deliver the water. The pump curve was only assumed and based on examples in the references and can be seen on Figure 4. The pipe diameters are 8 and 12 inches. The smaller pipes are the pipes going to the demand node and the larger ones are for the water mains. The roughness for each pipe was set to 100. The tanks were elevated to 50 ft and placed on each end of the street with an initial level of 10 ft and diameter of 50 ftAfter setting up all the details, the system was analyzed. The simulation duration was for 24 hours using the demand pattern on Figure 3. EPANET was able to determine the demand and pressure in the junctions/nodes and tanks, and the velocity in each pipe.The area for this study is only hypothetical and thus, the following assumptions were made: The area is approximately 10.45 hectares (450 ft x 2500 ft). Each household consists of 4 persons based on studies (Rufino, 2013) The design is based on the provisions of Peterborough Utilities Commission The average day demand is 450 liters per capita per day Hazen-Williams Equation will be used for solving The demand pattern (ranging from 0.7-1.65) can be seen on Figure 3 below:

Figure 3. Researched Demand Pattern

The pump curve is also shown below as computed in EPANET and based on research:

Figure 4. Pump Curve used in the designIII. ResultsThe analysis yielded the pressure at each node and tank and the velocity in the pipes for a duration of 24 hours. The figures below show the flow of water and pressure at time periods (Day 1) 12:00 AM, 8:00 AM, 11:00 PM and (Day 2) 12:00 AM.

Figure 6. Pressure at the Nodes, Day 2 12:00 AM

Figure 7. Pressure at the Nodes, Day 1 12:00 AM

Figure 8. Pressure at the Nodes, Day 1 8:00 AM

Figure 9. Pressure at the Nodes, Day 1 11:00 PM

Figure 10. Velocity at the Pipes, Day 1 12:00 AM

Figure 11. Velocity at the Pipes, Day 1 8:00 AM

Figure 12. Velocity at the Pipes, Day 1 11:00 PM

Figure 13. Velocity at the Pipes, Day 2 12:00 AM

The following tables below show the determined values by EPANET. The chosen nodes (for they have the highest and lowest values) and link are specified in the layout below.

Figure 14. Location of links and nodes indicated by the tables

Table 1. Time Series Table for Nodes

Time Node JU41Node JU341Node JU1Node JU9

Head Pressure Head Pressure Head Pressure Head Pressure

Hours ft psi ft psi ft psi ft psi

0:0066.428.77602667.2129.126026

1:0067.4529.2360.012668.1829.5460.0326.01

2:0068.4729.6760.0726.0369.1329.9560.0926.04

3:0069.4530.0960.1326.0670.0530.3560.1626.07

4:0070.4130.5160.2126.0970.9530.7460.2526.11

5:0071.3330.9160.326.1371.8231.1260.3526.15

6:0072.2131.2960.426.1772.6531.4860.4526.19

7:0073.0631.6660.526.2273.4631.8360.5626.24

8:0081.1935.1860.6226.2781.1935.1860.6926.3

9:0081.8535.4760.7526.3281.8535.4760.8426.36

10:0082.5535.7760.926.3982.5535.776126.43

11:0083.1836.0461.0726.4683.1836.0461.1926.51

12:0088.5338.3661.2626.5488.5338.3661.426.61

13:0089.1138.6161.4726.6389.1138.6161.6226.7

14:0089.6538.8561.6926.7389.6538.8561.8626.81

15:0093.6640.5861.9326.8393.6640.5862.1426.92

16:0093.8340.6662.1826.9493.8340.6662.4127.04

17:0094.3340.8762.4427.0694.3340.8762.727.17

18:0094.8741.1162.7227.1894.8741.116327.3

19:0095.3541.3163.0227.3195.3541.3163.3327.44

20:0098.4842.6763.3727.4698.4842.6763.7627.63

21:0098.8242.8263.7327.6298.8242.8264.1527.8

22:0099.2943.0264.1127.7899.2943.0264.5627.98

23:0099.5843.1564.5127.9599.5843.1564.9828.16

24:00:00102.3244.3464.9928.16102.3244.3465.6728.45

Table 2. Time Series Table for Pipes

Time Link PI1Link PI26Link PI8Link PI458

Flow Velocity Headloss Flow Velocity Headloss Flow Velocity Headloss Flow Velocity Headloss

Hours CFS fps ft/Kft CFS fps ft/Kft CFS fps ft/Kft CFS fps ft/Kft

0:00-2.383.034.640.921.180.810.030.0400.020.020

1:00-2.443.114.890.871.110.730.080.10.010.040.050

2:00-2.513.195.130.831.050.660.090.120.010.050.060

3:00-2.563.275.350.7810.60.110.140.020.060.070

4:00-2.623.335.550.740.950.540.130.160.020.060.080.01

5:00-2.673.45.750.70.90.490.140.180.020.070.090.01

6:00-2.713.455.930.670.850.440.150.190.030.080.10.01

7:00-2.753.516.10.630.810.40.160.210.030.080.10.01

8:00-3.714.7310.610.020.0300.180.230.040.090.120.01

9:00-3.694.710.50.020.0200.20.250.050.10.120.01

10:00-3.684.6810.420.010.0200.210.270.050.10.130.01

11:00-3.664.6610.320.010.0100.220.280.060.110.140.02

12:00-3.454.49.280.010.0200.240.310.070.120.160.02

13:00-3.444.379.190.010.0100.260.330.080.130.160.02

14:00-3.424.359.090.010.0100.270.350.080.140.170.02

15:00-3.254.148.280.010.0200.30.380.10.150.190.03

16:00-3.234.118.20.020.0200.320.40.110.160.20.03

17:00-3.214.098.120.020.0200.330.430.120.170.210.03

18:00-3.24.078.040.010.0200.350.450.130.170.220.04

19:00-3.184.057.970.010.0100.360.460.140.180.230.04

20:00-3.053.887.360.010.0100.410.530.180.210.260.05

21:00-3.033.867.290.010.0100.430.550.20.220.270.05

22:00-3.013.847.210.010.0100.450.570.210.220.280.06

23:00-33.827.140.010.0100.460.580.220.230.290.06

24:00-2.883.666.610.010.0100.550.70.310.280.350.09

IV. ConclusionThe simulation yielded the probable pressure and velocity of the designed water distribution system. The highest pressure reached was less than 50 psi and the highest velocity reached in the pipes was 4.7 fps. In the provisions in designing a water distribution system of a subdivision, the velocity must not exceed 5 fps and the pressure in each demand node must be less than 100 psi. The design was altered to meet these conditions. The pump curve was adjusted to lower head from the original 300 head to 100 head. This shows the dependency of the whole system on the type of pump used for the reservoir. Pressure reducing valves were no longer added to the system since the pressure in the demand nodes is much lesser than the design pressure required. Overall, the pressure in all the demand nodes is acceptable although the pressure at farthest from the reservoir is almost half of that from the nearest. Also, the velocity for each pipe is safe and will not be too fast and dangerous. The design of fire hydrant and other public water services were not included in this simulation. The design is simply for the residential use of water in a subdivision except for the storage tanks at each end of the street to provide for emergency water use in case high demand and low available water source. V. References1. EPANET Users Manual2. Watercare Services Limited Water and Wastewater Code of Practice for Land Development and Subdivision3. Rufino, Cesar. Consumption Pattern of Poor Households in Metro Manila A Microeconomic Evaluation pp. 15. 2013. Manila, Philippines4. Water Subdivision and Development Requirements by the Peterborough Utilities Commission