Optimising the distribution system of existing scarce water supply in a mountain indigenous community

Figures & data

Figure 1. Schematic of the water supply system of Bontoc, Mountain Province.

Table 1. Discharge from water sources (L/s).

Source	Minimum discharge	Maximum discharge	Mean discharge
Sullong Water Source	4.7	51.8	20.6
Balabag Water Source	5.47	109	41.96
Gakhan Water Source (under development)	10.37	53.4	30.77

Figure 2. Consumption patterns per category.

Table 2. Water demand per category.

Category	Types of demand	Quantity (L/day)
1	Residential water consumption	115
2	Commercial water consumption	2718
3	Government institution water consumption	4644
4	Hospital water consumption	57,167

Figure 3. Distribution network base map as of 2021.

Figure 4. Control panels A and B.

Table 3. Current water service hours.

Number of manifolds	am		pm	Number of taps supplied
2	4.00–6.00			46
8	6.00–8.00			161
1	6.00–10.00			50
3	6.00–11.00			75
1	6.00	to	4.00	2
5	8.00–10.00			48
4	10.00	to	12.00	86
4	11.00	to	1.00	83
15			1.00–4.00	383
3			4.00–6.00	6
7			6.00–10.00	138
8	6.00–10.00	and	10.00–4.00am	313
1	12.00	to	11.59	14
1	12.00	to	11.59	1

Table 4. Manifolds and population per barangay.

Barangay	Number of manifolds	Number of taps connected
Bontoc Ili	13	359
Caluttit	14	269
Poblacion	19	497
Samoki	16	240
Illegal taps	N/A^a	41
Total	62	1406

^aIllegal taps are connected on main lines.

Table 5. Tank dimensions.

Tank	Volume (m^3)	Actual capacity (m^3)	Height (m)	Calculated diameter (m)	Elevation (m amsl)	Initial level (m)
Balabag Tank 1	22.5	19.8	2.2	3.38	1858	1.1
Balabag Tank 2	21.43	21.13	2.32	3.43	927	1.16
Sullong Tank	23.4	22.5	2.5	3.39	1001	1.25

Table 6. Pipe diameter and lengths.

Pipe nominal diameter		Total length (m)
inches	mm
½	15	1914
¾	20	1984
1	25	3880
2	50	5970
5	125	14,626
6	150	1593

Figure 5. Framework of the study.

Figure 6. Process of GIS data conversion to EPANET.

Figure 7. Waterworks distribution system elements imported into EPANET.

Figure 8. Contour plot.

Figure 9. Elevation and pipe diameters.

Figure 10. Pressure and velocity during peak demand.

Table 7. Optimised number of taps to be supplied using Equation (1).

Tank	Discharge (Dm) in L/s	Service Time (Tt) in h	Household water demand (WDh) in L/day	Mean number of household members (HNm)	Number of optimised taps to be supplied (Tn)
Balabag Tank 1	14	24	115	6	1753
Sullong Tank	6	24	115	6	751

Table 8. Calculated warning discharges for water supply variation.

Tank	Tank capacity (Ctank)	Main pipe discharge (D)	Total service time (Tt)	Warning discharge to lower water service time	Warning discharge to add water service time
Balabag Tank 1	14 m^3	14 L/s	24 h	13.97 L/s	14.08 L/s
Sullong Tank	10 m^3	6 L/s	24 h	9.98 L/s	10.06 L/s

Figure 11. Schematic diagram of water service time distribution.

Figure 12. Time difference in the water service schedule between the existing and optimised values.

Data availability statement

The data that support the findings of this study are available from the corresponding author, E.B. Magwilang, upon reasonable request.