Don Duong Reservoir: Effectively controlling floods, providing abundant water for agriculture production

Don Duong reservoir of Da Nhim hydropower plant is a strategic multi-purpose hydropower reservoir, both generating electricity, supplying water for the downstream area and controlling floods on the upstream Dong Nai River.

Located on the upstream Dong Nai river system, Don Duong reservoir belongs to Da Nhim hydropower plant of Da Nhim - Ham Thuan - Da Mi Hydropower Joint Stock Company. Don Duong reservoir receives water from the Da Nhim River and the Kronglet River, which originates from Lac Duong District, Lam Dong Province.

Don Duong reservoir has a large catchment area (775 km2) but a quite small storage capacity (165 million m3), therefore the water level of the reservoir rises quickly in the flood season. According to the inter-reservoir operation procedure for Dong Nai river basin, the flood season in Don Duong reservoir starts from August 1 to December 31 every year. Floods often appear on Don Duong reservoir in the last months of the year, when the upstream Dong Nai River comes into the main rainy season. The safe and efficient operation of Don Duong reservoir so as to mitigate adverse impacts on the downstream area in the flood season poses many challenges for Da Nhim - Ham Thuan - Da Mi Hydropower Joint Stock Company.

In 2020, there were 4 floods to Don Duong reservoir.

The water level of Don Duong reservoir reached a height of 1,036.9 m at 5:00 p.m. on 13 September 2021

Typically, flood No. 1 appeared at 2 o'clock on 11 October 2020 with the maximum flood volume of 277 m3/s, the maximum discharge flow of 25m3/s, reducing the flood peak by 90.97%. Or flood No. 4 appeared at 6 o'clock on November 29, 2020 with the maximum flood volume of 687 m3/s, the maximum discharge flow of 500 m3/s, reducing the flood peak by 27.22%.

Thanks to good coordination with the local authorities and the National Load Dispatch Center (A0) during the reservoir operation, generating unit dispatching and exploitation, the discharge flow regulated through the spillway of Don Duong reservoir is always lower than the flood inflow, contributing to minimizing damage to the downstream area.

Annually the company actively works with the Department of Agriculture and Rural Development and related agencies to agree on the water supply volume for Ninh Thuan province from time to time to achieve the highest efficiency in power generation and water supply for the downstream area.

At this time, Don Duong reservoir has entered the flood season of 2021 with the dual task of both supplying water to run generators and participating in flood reduction, contributing to mitigating negative impacts on the downstream area. Previously, the company carried out an inspection of the operating status of equipment and key structures such as dams, water intake gates, discharge gates, etc. Along with that, the company has collaborated with relevant authorities to inspect the current downstream water flow condition to ensure safety when discharging floods.

From 9:00 to 17:00 on 17 September 2021: Da Nhim - Ham Thuan - Da Mi Hydropower Joint Stock Company will discharge water through the Don Duong spillway to inspect the spillway structure and equipment, and clear blockages if any in the downstream flow with a discharge flow from 25 m3/s to 50 m3/s. On September 10, 2021, the company informed the water discharge to the Steering Committee for Disaster Prevention, Search and Rescue of Lam Dong Province, the local authorities of Don Duong District, Duc Trong District and relevant agencies.

  • 13/09/2021 12:50
  • 143