Penang’s 3 key dams Effective Capacity
1. Mengkuang Dam 86.40 bllion litres
2. Teluk Bahang Dam 18.24 billion litres
3. Air Itam Dam 2.16 billion litres

The Mengkuang Dam has been expanded to meet Penang’s water supply needs during annual dry seasons in the 21st Century.

On 14.12.1985, the Yang DiPertua Negeri (Governor) of Penang, TYT Tun Datuk Dr. Haji Awang bin Hassan, officially opened the “original” Mengkuang Dam. About 35 years ago, its maximum effective capacity was 22.0 billion litres.

The Mengkuang Dam Expansion Project (MDEP) is undertaken by the Malaysian Federal Government as part of its commitments to Penang for migrating to the National Water Services Restructuring Initiative (NWSRI) in 2011.

Works commenced from 2011. Phase 1 of the MDEP saw the construction of a new dam with a crest length of 2km and a maximum height of 56.6m; as well as the raising of the original dam structure by 11m and other associated works.

The two dams were subsequently “joined” to form one significantly larger body of water with a maximum surface area of 3.4 sq. km (as compared to 1.74 sq. km previously). Today, the maximum effective capacity of the dam is 86.40 billion litres.

On 26.10.2020, the Federal Government officially handed back the expanded Mengkuang Dam to the Penang State Government.

Funded by a RM1.2 billion Federal grant, the full work scope of the MDEP comprises 4 key phases:

Phases Status (as at 26.10.2020)
1 Expansion of the Mengkuang Dam’s effective capacity from 22.0 billion litres to 86.40 billion litres and associated works. Completed (10.4.2017)
2A Upgrading of the Mak Sulong Pumping Station, to increase raw water pumping capacity from Sungai Kulim, from 200 million litres per day (MLD) to 400 MLD. Completed (28.9.2017)
2B Laying of 7km of a 1.6m diameter raw water pipeline from the Mak Sulong Pumping Station to the Sungai Dua Canal. This new pipeline will upgrade the raw water drawdown capacity of the dam from 300 MLD to 600 MLD. Final stage of land acquisition. The Ministry of Environment and Water (KASA)’s water supply section to implement this project in 2021.
2C Construction of the 440 MLD Lahar Yooi Pumping Station to enable rapid filling and refilling of the dam by pumping water from a second raw water resource: Sungai Muda. Included in the Feasibility Study to construct a new barrage at Rantau Panjang for consideration by the Federal Government.

MDEP: Function & Rationale

The Mengkuang Dam is the core component of the “Mengkuang Pumped Water Storage Scheme”. The “pumped storage” aspect differentiates the Mengkuang Dam from the other key dams in Penang.

Unlike the Air Itam Dam and Teluk Bahang Dam which primarily store raw water from nearby water catchment areas, the Mengkuang Dam is built to primarily store raw water pumped from Sungai Muda and Sungai Kulim during the wet seasons.

During dry seasons, the raw water stored in the Mengkuang Dam is released when the levels of Sungai Muda (at Penang’s Lahar Tiang Intake) is low.

Water released from this dam during dry seasons is channelled, via Sungai Dua Canal at Lahar Yooi, to the Sungai Dua Water Treatment Plant (WTP), Penang’s most important WTP. The Sungai Dua WTP produces more than 80% of the treated water that is supplied throughout Penang daily.

In the past two decades, water consumption in Penang had increased by 57.3%, from 536 million litres per day (MLD) in 1999 to 843 MLD in 2019. Looking ahead, water consumption in Penang is projected to reach 1,884 MLD by 2050.

Accordingly, the primary rationale for the MDEP is to upgrade the capacity and performance of the Mengkuang Dam to meet Penang’s water supply needs in the 21st Century. The objectives are to expand the dam to store more water, by pumping excess water into the dam during the wet seasons, thereby mitigating floods, and the release of more water from the dam during dry seasons.

As such, the Penang State Government and Perbadanan Bekalan Air Pulau Pinang Sdn Bhd (PBAPP) are seeking the kind cooperation of the Federal Government to complete the MDEP in entirety, as promised.