The International Steam Pages

Penang Hills and Trails - PBA Rain Gauges

This is one of a series of pages on walking the hills of Penang, click here for the index. There is a map at the bottom of the page.

I have prepared some pages on 'water' in the context of Penang's hills, covering rain gauges, catchment areas and some of the lesser known dams and reservoirs. I must stress that what is presented is unofficial and empirical, derived almost entirely from what I have found as I have explored. Unfortunately, while the various bodies which are involved are quite good at erecting signs (which are then left to rust) they are poor at public communication. You can search the web in vain for any official information and on the one occasion I tried to approach the PBA directly, it was like communicating with a brick wall.

See also:

March 2024

Revised advice about access to the Fettes Aqueducts (10th March 2024)

January 2024

I have added a picture taken at Teluk Bahang Dam (27th January 2024)

January 2023

I have added a couple of pictures taken at Sungai Pinang Water Treatment Works (11th January 2023)

January 2020

A typical pair has appeared next to the car park at the Air Itam Dam, they have no number on them. Thanks to Peter van der Lans for the tip off. The modern one is powered off the mains supply as opposed to the usual battery. I now understand that most PBA installations now have (unnumbered) rain gauges of the non-traditional design. Necessarily these are not accessible on a casual basis.

July 2019 / January 2020 / February 2020 / August 2020 / September 2020 Update

Following the Great Storm of November 2017, the PBA seems to have instigated a programme to reactivate and upgrade rain gauges. This particularly affects the low number (1-10) first generation rain gauges. Peter van der Lans has told me that RG 2, 3, 4, 9 and 10 now have second generation rain gauges, from my own observations RG 6 and 7 also. I assume that 5 and 8 will have had the same treatment but I cannot confirm it. RG 5 is known to still be on Western Hill inside the secure area, I assume it would have fallen out of use like the others in the area but will also have been upgraded.

Peter tells me that the RG 20 'box' was empty in January 2020, I believe the accessible RG 16 is working but I have no recent information on RG 17-19 in the same area.

Of the four 'Laksamana RG (11 - 14), I found 13 to be an empty box and 14 without a battery in February 2020. Given that 11 was long abandoned and never modernised and 12 is even more inaccessible, I doubt they have been revived. By August 2020, 11, 12 and 14 had been revived but 13 was still out of use (Source, Peter van der Lans).

Those Teluk Bahang RG I have seen (21, 22, 23, 25, 26 and 27) in the last year appeared serviceable.

The Air Itam Dam rain gauges (28 - 35) seem to be in use.

In other words there is a limit to their enthusiasm and they prioritised those which are in the public eye, those that are easy to read and those that relate to the dams at Air Itam and Teluk Bahang.

The locations of RG 1 and RG 5 have been confirmed, neither is accessible to a casual visitor, locations are below (13th September 2020).

PBA (Perbadanan Bekalan Air) is the body charged with the public water supply in Penang. They have significant dams at Air Itam, Teluk Bahang and Mengkuang (in Seberang Prai) together with smaller dams and reservoirs elsewhere. They operate the Fettes aqueduct behind Batu Ferringhi and a system of interconnected pipelines. In fact, I have read that this supplies barely 20% of Penang's needs, the rest coming from the Muda river which mainly runs through neighbouring Kedah but at its lowest end forms the border with Penang - from where the water is taken. Amazingly, Penang has both the cheapest water in the country (thanks to a massive subsidy) and the highest per capita consumption, no doubt the two are related and it's clearly not sustainable.

They are also responsible for maintaining the integrity of water catchment areas, hikers will be familiar with their (often decaying) warning notices which are to be found mainly in the upland areas of the north of the island. Associated with this is the maintenance of a collection of rain gauges (RG) which are for the most part positioned at higher points in the principal catchment areas. Many of the ridge paths and others used by hikers were established to service them and a number of these gauges were historically noted in passing in my hike reports. RG 1 to 11 are well out of use, usually left as historical curiosities, others (RG 12 to 35) have been replaced with modern electronic logging equipment which needs visiting once a month or so to retrieve data. However, in many cases these too are now disused as the kit has proved unreliable in Penang's climate. Most are on quite well used paths but in some cases paths which would otherwise see almost no use have had to be kept open at least in part. PBA has a master list, but to date, I have been unable to access it; I have though seen a map of unknown vintage (marked 'uncontrolled') which shows approximate locations. It correlates well with the gauges I have visited except for RG 9 which is plain wrong although some are definitely slightly misplaced (eg RG 22 and 23 which are actually higher up towards Bukit Laksamana). I now know that RG 7 is also misplaced.

Helpfully, each bears a number and as most are grouped logically by area it was possible to anticipate where missing ones might be found. The list below shows known locations and the original source of my information (GM = Guillaume Martin, LM = 'Larry Malay', PL = Peter van der Lans). Click the links for each number for my report on visiting them, almost complete as of March 2016. I should add that previously about 10 of them were also reported in Forest Ang's "Selected Nature Trails of Penang Island" book.

It's been a real pleasure 'collecting' the rain gauges, in several cases it has brought me to areas where I had not thought to hike before. Almost all lie on 'jungle' paths and as such it is very much hiking without a view compared our more familiar areas in the south of the island.

RG Reported by Catchment Area
 1 Anon Waterfall Beside the reservoir in the Botanic Gardens, 526'24.79"N, 10017'6.43"E.
 2 GM " Above the Botanic Gardens, near the waterfall
 3 GM " Above the Botanic Gardens on the path to Western Hill / former Crag Hotel
 4 GM " Above the Botanic Gardens on the path to Western Hill / former Crag Hotel, above RG 3
 5 Anon " On Western Hill inside the current security area, 525'36.89"N, 10015'5.76"E
 6 GM " On Summit Road between Bukit Bendera and Tiger Hill.
 7 PL " Off Summit Road near Tiger Hill.
 8 RD " Next to Richmond Bungalow on the main part of Penang Hill
 9 GM " Above the Botanic Gardens on the path to Western Hill / former Crag Hotel, above RG 4. Incorrectly marked on the PBA map.
10 GM " On Bukit Cendana
11 GM Batu Ferringhi East of Bukit Laksamana on the Teluk Bahang to Western Hill path, below 12 (abandoned)
12 GM " East of Bukit Laksamana on the Teluk Bahang to Western Hill path just below the summit.
13 GM " North of Bukit Laksamana on the Teluk Bahang to Western Hill path, above 14
14 GM " North of Bukit Laksamana on the Teluk Bahang to Western Hill path
15 GM " On the path from the Batu Ferringhi Dam towards Bukit Laksamana, below RG 21
16 LM " Near the point where the two halves of the aqueduct join above Batu Ferringhi
17 GM/LM " On the eastern path from the lower end of the upper Fettes aqueduct to Western Hill, Bukit Cempedak
18 GM/LM " On the eastern path from the lower end of the upper Fettes aqueduct to Western Hill, above RG 17
19 GM/LM " On the eastern path from the lower end of the upper Fettes aqueduct to Western Hill, above RG 18
20 GM " On the western path from the upper end of the upper Fettes aqueduct to Western Hill
21 GM Teluk Bahang On the path from the Batu Ferringhi Dam towards Bukit Laksamana, above RG 15 and below RG 14
22 PL " Below Bukit Laksamana on the trail to / from the Tropical Fruit Farm
23 PL " Below Bukit Laksamana on the trail to / from the Tropical Fruit Farm, below RG 22
24 RD " On a hill above Pantai Acheh village, south of RG 25
25 RD " Between RG 24 and RG 26, at the south end of the ridge path down from Bukit Batu Itam
26 GM " At the summit of Bukit Batu Itam west of Teluk Bahang Dam, south of RG 27
27 GM " On the path from the United Hokkien Cemetery, Teluk Bahang to Bukit Batu Itam west of Teluk Bahang Dam
28 GM Air Itam Dam On the path from Air Itam Dam to Tiger Hill Ridge, below RG 29 (moved some way downhill in 2017)
29 GM " On Tiger Hill Ridge, above RG 28  (moved 1km south along the ridge in 2017)
30 RD " On Tiger Hill Ridge, above the path near the 5 way junction
31 PL " On Bukit Elvira between the two easterly peaks (moved south, now at 523'30.62"N,10014'31.17"E)
32 PL " At a farm above the Bao Tian Gong temple, just below the forest edge on the south side of Bukit Elvira (moved to the access road below the farm, 522'54.43"N,10014'42.72"E
33 RD " Next to the road to the Bukit Penara masts above 34.
34 RD " Off the road to the Bukit Penara masts, just before the path to the 1200 Step temple.
35 RD " Next to the road west from Air Itam Dam to the '5 way junction' on Tiger Hill Ridge
? RD Batu Ferringhi Railings only on Carla's Peak above Mount Pleasure Resort, between Tanjung Bunga and Batu Ferringhi, possibly the missing RG 1 but unlikely as I believe this to be the one at the Air Itam Reservoir. This will have served the Sungai Siru catchment area.
Unnumbered Not shown on the PBA map, in a secure area at the Air Itam Reservoir.

The map shows the approximate locations of those RG I have visited together with my estimation of the various catchment areas. According to the web there are 8 gazetted water catchment areas but I have not been able to find details. Since first drawing the map, blue signs have started to appear on the hills, which name the catchment area concerned, I have made additions to the map below as a result. It is still incomplete, the area to the west of the Batu Ferringhi dam has signs for 'Anak Sungai 3V Side Stream'. I believe there will be other (small) catchment areas on the main hill above the Air Itam Dam.

I am far from convinced by some of the signs, for instance 'Sungai Kelian' is rendered as 'Sungai Klean' which perpetuates a mistake on a PBA map. The sign which bears 'Sungai Tengah' should, I believe read 'Sungai Kecil'. As for the signs that read 'Gilemard', words just fail me. On older maps, the area around what I call the Laksamana stream above Titi Kerawang was known as the Laksamana Catchment Area, but I have yet to see any blue signs there because I have not visited since they were erected.

WF = Waterfall
TB = Teluk Bahang
AI = Air Itam
BF A = Batu Ferringhi, upper aqueduct
BF B = Batu Ferringhi, lower aqueduct
SP = Sungai Pinang
SKl = Sungai Kelian
SS = Sungai Siru
SK = Sungai Kecil
AST = Anak Sungai Tat

I have not included paths but these will be shown at the bottom of the reports linked above. I have not added the RGs to those maps as not everyone will be interested. Note that this is still my original map and some have moved but it would hardly show at this scale.

Rob and Yuehong Dickinson