Rapid Assessment for Resilient Recovery and ... - GFDRR

For the western canal system of the Chao Phraya River, the current draining system
through the Chao Phraya River and Tha Chin River requires development of
north-south canals to promote the drainage to the sea through Thawee Watthana
Canal, Ratchamontri Canal and Bang Namjued Canal.
1.3 Pumping System to the Sea
Water pumping system in eastern coast of Samutprakarn has both the old system
connecting mainly to Chaiyanuchit Canal and the drainage system of Suvarnabhumi
Airport connecting to Samrong Canal. It is founded that the level of the canals has
decreased especially in the area northern of Bangna-Trad road causing the canals
to unable to feed water to the pumping system efficiently. The pumping system can
only work at less than 50 percent of its capacity. This requires improvement of the
existing pumping system and increase the number of storage pool before feeding to
the pumping system.
2. Expansion of the system by following the Royal Initiatives
2.1 Increase the draining capacity of the Raphiphat Canal to Klong Dan
and Bangpakong River
Raphiphat canal is an important canal as it diverses water from Pasak River and Lop
Buri River from joining the Chao Phraya River at Phra Nakhon Sri Ayuthaya District,
Phra Nakhon Sri Ayuthaya Province by using Rama VI Dam and Phra Narai Watergate
to separate water to the east side and drain to Raphiphat canal before transmitting
to the drainage system of Nakhon Nayok River and Bang Pakong River as well as
the Coastal Pumping System. Currently, the draining capacity is at 200 cubic meters/
second. This requires increasing the capacity to 300 – 400 cubic meters/ second.
The current capacity of Southern Raphiphat canal is 150 cubic meters/ second and
will require capacity increase to 250 – 300 cubic meters/ second.
2.2 Expand the outer ring road to be used as flood way
The Kanchanapisek outer ring road on the east side has side areas that could be
developed into flood way for draining water to the pumping system at Klong Da,
Suvarnabhumi drainage canal, and the east and west seacoast. It is recommended
that the road should be expanded to be used as flood way and for commuting during
normal time, or could be further developed by installing drainage pipe underground.
2.3 Rehabilitate and develop “Monkey Cheek” in Bueng Boraphet and
Bueng Si Fai
The lower part of the northern region has large swamps and bogs, such as Bueng
Boraphet and Bueng Si Fai which are natural “monkey cheek” for water retention.
Currently, these areas have been deteriorated (for example, Bueng Boraphet is
clogged with about more than 1.5 milion tons of dregs per year). These water
retention areas need to be rehabilitated and connected to rivers as well as develop
and conserve in a balance way.
2.4 Develop 2 in 1 waterway, that is for transmitting and draining,
such as Chai Nat – Pasak canal, Phra Pimon Canal and Phraya
Bunlue canal
3. Establish National Knowledge Bank for Cooperative Water
Management
“The Water Management Network of Thailand” under Royal Initiatives starts
operating since 1999. The network collects data and link network on water resource
and Thailand climate together in order for responsible agencies to utilize the data
for management decision making during normal time and for monitoring and warn-
A-32 THAI FLOOD 2011 RAPID ASSESSMENT FOR RESILIENT RECOVERY AND RECONSTRUCTION PLANNING