Khlong Lat Pho

The Lat Pho Canal was originally a small and shallow canal of 10-15 meter width and 1-2 meter depth. The 600 meter long canal was excavated to shortcut the river at the Bang Kracho meander neck in Song Khanong Sub-district in Phra Pradaeng District, reducing the journey for small boats with 19 kilometers. Unfortunately, because the Chao Phraya is tide-affected, the canal introduced saline water into the upper river, damaging marine and river-bank life. In 1784 a dam was built across the small canal to halt salt water intrusion which seeped into the irrigation system that fed the orchards established here.
On 7 November 1995 (a massive flood year) a Royal decision started the planning of the Khlong Lat Pho Dredging and Improvement Project together with the construction of flood gates. The project was aimed at accelerating the drainage of excess flood of the Chao Phraya River in its meander belt section named "Bang Krachao" of 18 kilometer length in Samut Prakan Province. To shorten the distance of the river flow and accelerate the flow to the Gulf of Siam, an existing shortcut canal of 600 meter length was dredged to a depth of 7 meters and widened from its 15 meters width to 65 meters width in order to alleviated the flood over Bangkok area. Four flood gates of 14-meter width and 9.55-meter height were installed.
On 24 November 2010 King Bhumibol Adulyadej (reign 1946-2016), accompanied by Her Royal Highness Princess Maha Chakri Sirindhorn, travelled by boat to Khlong Lat Pho to preside over the inauguration of the two bridges and the floodgates of this short-cut canal. During flood peak season, the river flow from the North is so strong that the flood can be drained to the sea even in high tide duration, which enables 24 hour gate opening. The efficiency of the drainage of the Chao Phraya river increased by 10-15% without damaging the remaining eco-system of Phra Pradaeng District. [Ref: Royal Irrigation Department of Thailand website and National News Bureau of Thailand website - 30 October 2016; Van Beeck, Steve - Chao Phya in Transition - page 39]

Ayutthaya Historical Research