Decreasing water quality affecting Putrajaya Lake and Wetlands

However, many may not know that in addition to being a recreational spot, the largest manmade lake in the tropical region has been recognised by UNESCO as an Ecohydrology Demonstration Site, as well as an example of integrated lake basin management under the International Hydrological Programme (IHP).

Ecohydrology is an interdisciplinary field studying the interactions between water an ecosystems.

The integrated water catchment concept at the Putrajaya Lake and Wetlands has earned it a Stage 2 classification under the IHP, making it one of the only seven operation demonstrations sites of the programme.

It is also the only lake in Southeast Asia to hold the position since its selection in 2010.

The lake basins are subjected to four stages of classification. Stage Four is the most basic, called the Emerging Projects; Stage Three is the Evolving Projects, a basin that has yet to become operational; Stage Two is the Operational Projects, an established basin which may become a World Demonstration Basin in due course and Stage One is the Global Reference Project, a basin that demonstrates the best practice in the UNESCO-IHP Ecohydrology Programme.

THE CHALLENGES

However, after seven years at Stage Two, the Putrajaya Lake and Wetlands is struggling to protect its water quality from the effects of pollution.

The problem could compromise its position as UNESCO's ecohydrological demonstration site and delay its chances to become a Global Reference Demo Site, which is a Stage One demonstration site under UNESCO's ecohydrology programme.

At the moment, only three other sites in the world are at Stage One. Two are in Poland and one in Portugal, with all three treated as live laboratories showcasing the balance between water and the ecosystem.

Of the eight issues raise at global demonstration sites, it has been identified that the only issue plaguing the Putrajaya Lake and Wetlands was pollution and decrease of water quality, said the supervisor of the UNESCO ecohydrology demonstration site, Dr Rahmah Elfithri.

The senior lecturer at Universiti Kebangsaan Malaysia's (UKM) Institute for Environment and Development (LESTARI) said that the problem was manmade as man were the main contributor to the destruction of present ecosystems.

If the lake's ecosystem was not preserved or rehabilitated, there was a high possibility that the lake would be further plagued by more issues, such as those experienced by other demonstration sites, she said.

Such issues include excessive water intake, invasive species, loss of habitat, intensive land use around the site, flood, drought and the inability to retain vegetation.

"Most of the pollution are due to human activities and it takes its toll on the water quality at the lake. The increase in pollution is parallel with the population and tourist increase," she told Bernama recently.

The Putrajaya Lake and Wetlands used to be the only lake in Malaysia which quality was at Class One. This means that it was safe enough to even drink straight from.

However, today, the water quality at the lake has gone down to Class Two.

Despite the decrease in water quality, it could still function as a recreational area. However, Rahmah was worried that the situation would worsen.

LESTARI, which has been studying the situation at the Putrajaya Lake and Wetlands from the beginning of its participation in the UNESCO programme, found that the most prominent form of pollution were the rubbish littering the lakesides.

The volume of rubbish would multiply every time an event involving a number of participants or visitors were held in the area.

In the early days in the programme, this was not the case. However, in recent years, the problem has exacerbated with drinking bottles and food wastes left indiscriminately around the site, she revealed.

"This problem is due to the attitude of visitors. They could be tourists or locals, but they leave rubbish everywhere, even though there are garbage bins around. There is a low level of awareness and responsibility," she said.

The change in the colour of the lakewater was also evident with it looking murkier by the lakesides, which is a favourite spot among tourists.

When the lake was first opened to the public, its water was crystal clear. Today, parts of it are so murky that it ranged from dark brown to black, she said.

"The main contributors of the turbidity are the recreational and business activities that are often held here, such as water sports programmes.

"What makes it worse is that the food leftovers left by eateries and waste from nearby construction are carried by the runoff into the lake, further polluting it," she said.

Rahmah said that water quality was also affected by the quality of the water source, which was the polluted Sungai Chua and Sungai Bisa.

If the water in both lakes becomes further polluted, the ability of the wetlands to filter the water before it enters the lakes would decrease.

"If we could decrease the level of pollution from the water source before it enters the wetlands, then only a little treatment would be needed. Otherwise, we would need more," she said.

In addition to that, the aging piping and irrigation systems in Putrajaya buildings and infrastructure (now over 15 years old) are also becoming more susceptible to damage and leaks.

This indirectly leads to waste and effluents being channelled straight into the lake.

However, further research is needed to determine the amount of pollution caused by the issue.

"This is where LESTARI comes in. We need to be proactive and take preemptive measures to ensure the quality of water and ecosystems in the lake and wetlands are rehabilitated and preserved," she said.

THE EFFORT BY PERBADANAN PUTRAJAYA

It is not easy to manage a 600-ha lake and wetlands in the middle of a city. The ecosystem of a manmade lake like the Putrajaya Lake and Wetlands requires regular maintenance.

Interestingly, the water here is treated using an environmentally-friendly method.

Before the water from Sungai Chua and Sungai Bisa enters the lake, it passes through a series of wetland cells that have been built just before the lake.

This 400-hectare lake area is where the natural filtration process takes place, as the species of water plants there act as a "kidney" to eliminate pollutants such as nitrogen and phosphorus.

In addition to improving water quality, the wetlands also preserve the ecological balance in the area.

Perbadanan Putrajaya, the body in charge of the Putrajaya Lake and Wetlands, admitted that the problem of pollution existed but described it as isolated and restricted to certain inlets only.

"It does not affect the whole lake. Such incidences are usually detected at the early stages and dealt with from the root source," said Normaliza Noordin, the Head Assistant Director of the Management of Ecohydrology of the Environmental, Lake and Wetlands Division of Perbadanan Putrajaya.

She explained that the water quality sampling for the physiochemical parameters were done monthly, biennially and annually at 17 locations in Putrajaya.

MAKE CLEANLINESS A PRIORITY

She said that rubbish and floatsam found in the lake were cleared continually to preserve the cleanliness of the lake.

Everyday, no less than 14 workers would conduct thorough cleaning works at the Putrajaya Lake. Eight of them would be in the lake in four boats while another six would work around the lakesides.

What remains a challenge is getting the community onboard in maintaining the cleanliness and water quality as awareness was still lacking.

"There needs to be a change in the way we handle food waste, wash waste, used fats and oils and rubbish. We cannot simply dispose of them in a public irrigation system, as it would then be channelled to a lake.

"A full commitment from all quarters can help with the sustainable management of the Putrajaya Lake and Wetlands, which benefits can be enjoyed by us as well as the future generations."