Ayutthaya Alerted to 10 cm Rise in Chao Phraya River
The National Water Resources Office warned that water levels in the Chao Phraya and Mae Nam Noi rivers near Ayutthaya could rise about 10 cm today as inflows from the Ping and Nan rivers decrease. The rise is expected before the water moves downstream to Pathum Thani, Nonthaburi, Bangkok and Samut Prakan, but officials say existing flood defenses can handle it and no significant impact is anticipated. They added that reservoir levels are stable and water releases are being managed to prevent flooding.
The National Water Resources Office (ONWR) reported on October 4, 2026, that the Ping and Nan rivers’ inflow into the Chao Phraya basin is decreasing. At 09:00 that day, the flow at Nakhon Sawan was about 2,119 cubic meters per second while the release rate remained at 2,500 cubic meters per second. Downstream, the Sakeng River still carries a large volume, but its flow is expected to drop in two to three days, allowing steady discharge. The Pasak Jolasid Dam has equal inflow and outflow, currently releasing about 450 cubic meters per second, which results in a discharge of 655 cubic meters per second at the Phra Ram 6 regulator in Ayutthaya. Despite this, areas along the Chao Phraya and Mae Nam Noi rivers in Ayutthaya may see water levels rise about 10 cm today as water from the Chao Phraya Dam arrives. ONWR said this water will continue to Pathum Thani, Nonthaburi, Bangkok and Samut Prakan, but existing embankments are high enough to prevent impact, though low‑lying or unprotected spots could be affected. Reservoirs in the west, including Vajiralongkorn Dam, can still hold about 83 million cubic meters, discharging 40 million cubic meters daily while receiving roughly 45 million cubic meters, keeping levels stable. Srinagarind Dam is at 95.55 % capacity with room for over 700 million cubic meters, and the Mae Klong River’s downstream storage exceeds 1,100 cubic meters, allowing floodwater to return to the river, though tidal influences may delay the process. The Meteorological Department predicts heavy rain in Kaeng Krachan, Phetchaburi, which may increase releases from Kaeng Krachan Dam; provincial officials and the Irrigation Department have set up an information center. In the east, Chachoengsao Province and Ongkharak District are seeing increased inflows, and the Rangsit South irrigation project, coordinated with the Bangkok Metropolitan Administration, is helping to discharge water. Overall, forecasted rain from October 5‑8 is not expected to significantly raise water levels in the Chao Phraya or Mae Klong reservoirs, and the situation remains manageable.
