Putrajaya Lake and Wetland

The 400 hectares Putrajaya Lake was created by inundating the valleys of Sungai Chuau and Sungai Bisa. The construction was started in 1998 and fully completed in 2002. The lake has been primarily designed to enhance the aesthetic appeal of Putrajaya. It is also planned to be used for sport and recreation as well as a tourist attraction. Putrajaya wetland is the first man-made wetland in Malaysia and the largest constructed freshwater wetland in the tropics. It was began to construct in March 1997 and was completed in August 1998. The 197 hectare project resulted in transforming an oil palm site into wetland ecosystem with the helps of modern technology and stringent environmental management methods in design and construction.

The Wetland

Figure 1: Putrajaya constructed wetland

Figure 1: Putrajaya constructed wetland

The Putrajaya constructed wetland system comprises of five arms with 23 cells as described in Figure 1. All the arms (except of Upper Bisa) eventually discharge to the Central Wetland, which make the 24 cells in all, before the water flows down into the Putrajaya Lake. They straddle the water courses of Sungai Chuau, Sungai Bisa and three tributaries. A series of rockfilled weirs was constructed along the five arms of the wetland to divide the 24 cells. Although all the five arms are connected, they differ in size, depths, plant communities and pollutant loads that it is designed to handle.

The basic processes happening in the cell zones are illustrated in Figure 2. Typical longitudinal cross-section and typical layout of a wetland cell are shown in Figure 3 and Figure 4 respectively.

The design features a multi-cell multi-stage system with flood retention capability to maximize the space available for colonisation by water plants. The roles of the plants are to intercept pollutants and to provide a root zone where bacteria and microorganisms can flourish to assist in filtering and removing water pollutants.

The Putrajaya Wetland cells and its structural components are the keys to the functioning of the wetlands for cleansing the river water. They are important in maintaining the broader ‘functional capacity’ and objectives of the wetlands, which include providing a habitat for local fauna, primarily mammals, water birds, reptiles, amphibians, fish and invertebrates; hydrological modification (by providing flood detention area and reducing peak discharges and flow velocities) and recreation (the wetlands are used for both passive and active recreation, and parkland for aesthetic and recreational value).

Figure 2 : Various reactions happening in the wetland cells

Figure 2 : Various reactions happening in the wetland cells

Figure 3: Longitudinal section of a typical wetland cell showing the Zone of Intermittent Inundation (F2 and F1), Wetland Zone (Zone 1, 2 and 3) and the Open Pond

Figure 3: Longitudinal section of a typical wetland cell showing the Zone of Intermittent Inundation (F2 and F1), Wetland Zone (Zone 1, 2 and 3) and the Open Pond

 

Figure 4: Typical layout of a wetland cell

Figure 4: Typical layout of a wetland cell

The principle features of the wetland are shown below :

Principal features of Putrajaya Wetlands (Area in hectares)

Total Area

Planted Area

Open Water

Weirs & Islands

Zone of Intermittent Inundation

Maintenance Tracks

197.20

77.70

76.80

9.60

23.70

9.40

 

The Putrajaya Lake

The lake is at the southern part of the wetland. About 60% of the lake water flow from the wetland and the remaining 40% is the direct discharge from bordering promenade. The 20 m width promenade is the buffer feature along the lake shorelines. The water surface area of the whole lake is about 400 hectares. The total volume of the whole lake water is about 23.5 million cubic meters and the water depth is in the range of 3 to 14 meters. The lake has been planned to cater for multi-functional uses, including recreation, fishing, water sports and water transport. The lake and its foreshores also form Putrajaya’s most popular resource for informal recreation as a waterfront city.

The principle features of the lake are shown  below.

Principal features of Putrajaya Lake

Catchments Area

Water Level

Surface Area

Storage Volume

Average Depth

Average Catchments Inflow

Average Retention Time

50.90 KM2

RL 21.00 M

400 ha

(4 K M2 )

23.50 mil. M3

6.60 M

200 million liters

132 days