Erratic Weather Brings Rain and Heat; Phayao Reservoir Water Level Drops Sharply as Dead Fish Float Ashore Amid Foul Odors

Phayao province is experiencing severe weather fluctuations with alternating rain and intense heat, causing water levels at Gwan Phayao reservoir to plummet dramatically. Dead fish, including snakehead and tilapia, are floating across the reservoir's surface and emitting a foul stench.

On May 1, 2025, authorities reported that weather conditions in Phayao remain highly unstable, with rain and scorching sunshine alternating rapidly and causing swift environmental changes. Gwan Phayao, a critical natural water source for the province, has seen its water level drop alarmingly. Current measurements show the water level at 390.35 meters with only 14.934 million cubic meters remaining—noticeably lower than the historical average for this period. The situation is causing serious concern among local fishermen and residents who depend on the reservoir for drinking water and agricultural irrigation.

Meanwhile, numerous dead fish have been discovered floating along various sections of the reservoir, including snakeheads, tilapia, and native species, creating a pervasive foul odor throughout the area. Authorities have begun urgent recovery efforts to bury the carcasses and prevent public health problems.

Experts attribute this phenomenon primarily to extreme weather volatility, which causes rapid water temperature fluctuations. Combined with falling water levels, this leads to a sharp decline in dissolved oxygen, causing fish to suffocate and die en masse. This pattern has become increasingly frequent over recent years, particularly during seasonal transitions.

If the crisis continues, it could have widespread ecological consequences for Gwan Phayao—a vital ecosystem and major natural tourism destination that generates substantial income for the region. Local residents are urging government agencies to take immediate action before the fish kill crisis worsens.