Because the river flows through Klang Valley, which is a heavily populated area of more than four million people, it is considerably polluted, because of deep siltation caused by human waste from informal settlers of the riverbank and even from some business establishments without septic tanks or sewage treatment plants and by soil carried by mudflows from mountains.

Heavy development has narrowed certain stretches of the river to the point that it resembles a large storm drain in some places.

Kuala Lumpur means "muddy estuary", and this definition almost applies to the modern time because of the siltation mentioned above.

The river begins in Ampang Jaya, Selangor, then turn down along Ampang–Kuala Lumpur Elevated Highway till the city centre.

[4] Other stretches downstream and upstream, such as between Abdullah Hukum/Mid Valley Megamall, and from Kampung Baru to Dato' Keramat were also straightened between independence and the 1980s.

In include diverting flood water from the Gombak River into a few stormwater ponds located in Batu, Jinjang and Kepong.

When regular drainage infrastructure is overwhelmed, vehicles are evacuated from the tunnel and the entire tube is used as a gigantic storm drain to prevent Kuala Lumpur from flooding.

The river's condition has been described as "between critical and bad" by Gareth Jones of Wessex Water, a UK-based company that is participating in the project.

Kamal Zaharin, the project mastermind, states that the plans include river cleaning, new source of drinking water, environmental protection, flood mitigation, commercial, tourism and land development activities.