Introduction:

Department of Irrigation and Drainage (DID) Malaysia has appointed REDAC to carry out a “Rehabilitation of Ex-Mining Ponds and Existing Wetland for Integrated Storm water Facilities” at DID Mechanical Section, Ipoh. In line with the implementation of the new urban drainage manual known as Manual Saliran Mesra Alam (MSMA), the Study will be a showcase for development of ex-mining ponds as storm water facilities in Perak and throughout Malaysia. The study is a pilot project that rehabilitates the ex-mining pond into multi-functional uses, which include recreational, water reuse and storm water retention purposes.

Background:

The study area consists of DID Mechanical Section covering an area of 88 acres. The area is located on Lot 40367 River Kinta, Kinta District. The study area is situated on a former ex-mining land which consists of sandy soil and largely sparsely vegetated. The main feature of the site is the two ex-mining ponds (Figure 1) which are located in the vicinity of the buildings. There are also swampy areas (Figure 2) which stretched along the eastern border of the site and some parts of the swampy area may extend outside the study area. Drainage system in the Study area is based on rapid disposal approach which disposes the surface runoff to the roadside concrete drain prior to discharging into River Kinta via the pump station located near by. The surface runoff from the open area flows into the two main ex-mining ponds which are connected to the River Kinta by earth drain.

The ex-mining pond and the existing wetland (swampy areas) shall be rehabilitated and restored into ecological ponds with multi-functional uses. The planning and design into the restoration and rehabilitation of the ecological ponds shall be based on the MSMA and fulfill the requirement of water quantity and quality control.

Existing Ex-Mining Pond 1		Existing Ex-Mining Pond 2
Figure 1 Ex-Mining Ponds				Figure 2 Several Common Wetland Species in the Project Area

Figure 3 Layout of Integrated Stormwater Facilities at DID Mechanical Section, Ipoh

Objectives of Study:

The objectives of this Study as are stated as below:

• To set-up an example and showcase of ex-mining pond rehabilitation and restoration as storm water facilities in Malaysia.
• To study the existing hydraulic and hydrologic characteristics of existing ponds and the surrounding drainage system.
• To evaluate the effectiveness of the proposed rehabilitation and restoration works
• To establish the data collection system to monitor the hydraulic, hydrology and water quality parameters in the study area.
• To carry out the cost benefit analysis for the proposed system.
• To establish the guideline for rehabilitation and restoration of ex-mining pond for storm water and recreational purposes.

Conceptual Design:

The main components of the proposed integrated storm water facilities (Figure 3) include Ex-mining pond 1 designed as a regional pond to control both water quantity and quality from the study site and the surrounding areas. The conveyance system is made of an engineered waterway with features those of natural rivers. Storm water runoff from the botanical garden is conveyed to the engineered waterway via swale. Further treatment of storm water runoff is provided through a constructed wetland connected to the Ex-Mining Pond 1 via the engineered waterway. The existing wetland will treat runoff from the nearby surrounding areas located outside of the study area. The Ex-Mining Pond 2 is designed as a community pond to control both water quantity and quality from the study site only. An automatic tidal gate is provided at the downstream end before the runoff is discharged to River Kinta.

Conclusions:

The design of the project is based on MSMA by providing a series of treatment train for both storm water quantity and quality control. The construction of the proposed storm water facilities will provide an excellent example of storm water management components for other locations throughout Malaysia.

Acknowledgements:

REDAC would like to thank DID Malaysia for continuing support by providing the contract research for the study.