According to the Binh Thuan Irrigation Works Exploitation Company, upstream areas of the Song Quao, Song Khan, Suoi Da, and Ba Bau reservoirs have continuously received rain in recent days. Heavy rain is forecast to continue, which could rapidly increase water inflow to the reservoirs.

The water discharge aims to create additional empty capacity in the reservoirs to accommodate floodwaters, reducing the need for large discharges during continuous heavy rain. However, river and stream levels downstream of the reservoirs may rise during this regulation period, so downstream residents need to monitor warnings.

All four reservoirs are expected to begin water regulation from 4 p.m. today. The affected areas include regions in Phan Thiet, Ham Thuan Nam, and Ham Thuan Bac, located along the Ca Ty River, Cai River, and estuary areas.

Downstream flood warning station at Song Quao reservoir. Photo: Tu Huynh

At Song Quao reservoir in Ham Thuan Bac Commune, the initial discharge rate will be 10-50 m³/s, which may then increase to 50-100 m³/s, depending on the reservoir's inflow and downstream conditions. Before opening spillways or increasing the discharge rate, the management unit will inform the local authorities of Ham Thuan, Ham Thang, and Phu Thuy to warn residents.

Ba Bau reservoir in Ham Thach Commune had a water level of 41,5 m on the morning of 23/9, which is 0,5 m below its normal operating level. The management unit plans to open up to two additional spillway gates, increasing the total number of open gates to a maximum of five. At the current water level, the spillway discharge rate is approximately 112 m³/s and could reach about 150 m³/s when the reservoir reaches elevation 42 m (water surface elevation relative to a benchmark, not reservoir depth).

Suoi Da reservoir in Hong Son Commune will be regulated with an initial discharge rate of 3-5 m³/s, which may later increase to 5-20 m³/s. Song Khan reservoir in Ham Thuan Bac Commune will regulate at 2-20 m³/s, depending on reservoir inflow and downstream conditions.

The Binh Thuan Irrigation Works Exploitation Company requested local authorities to announce the water regulation and guide downstream residents to take proactive preventive measures.

Many areas in Lam Dong have experienced heavy to very heavy rain in recent days. Authorities warned of flash flood risks on small rivers and streams; landslides on slopes, mountain passes, embankments, and localized flooding in low-lying areas and urban centers.

Tu Huynh