To increase the efficiency of waterworks to accommodate changing needs in the future, the Metropolitan Waterworks Authority entrusted TEAM GROUP to study, design and analyze

Khlong Prapa on the western side so that it can transmit raw water at a flow rate exceeding 60 cubic meters per second. The tasks included survey and design, cost estimation, tender document

preparation, and generating detailed design of the canal for accommodating raw water flow rates exceeding 45 cubic meters per second and 60 cubic meters per second. The project was

divided into two phases as follows:

The lower part of Khlong Prapa on the western side (Phase 1: Tha Chin River–Maha Sawat Water Treatment Plant). This is a 35-kilometer-long trapezoidal earth canal designed to move raw water at a maximum rate of 45 cubic meters per second. Raw water in the retention basin in front of Bang Len Raw Water Pumping Station will be pumped and moved through the lower part of the canal to the Maha Sawat Water Treatment Plant’s retention basin at the level specified for the raw water pump to work.

The upper part of Khlong Prapa on the western side (Phase 2: Tha Chin River–Mae Klong Dam). This section consists of a 5.06-kilometer-long U-shaped canal, a 39.70-kilometerlong trapezoidal concrete-lined canal, an earth canal that stretches for 25.48 kilometers to reach the Tha Chin River, and a 455-meterlong elevated flume. It was designed to move raw water at a maximum rate of 45 cubic meters per second. Via gravitation, raw water from Mae Klong Dam flows along 72 kilometers of the upper part of the canal before crossing beneath the Tha Chin River to the upstream retention basin of Bang Len Raw Water Pumping Station.