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Home > Basin > Mekong > Assessing the Water Demand Implications of Development Plans in Central Viet Nam

How do you promote better management of water from a reservoir that provides services to two independently managed, and rapidly growing, provinces? One CPWF Innovation Fund Project, entitled ‘Building Provincial Capacity to Understand the Water Demand Implications of Socio-Economic Development Plans in Central Viet Nam’ set out to answer that question.

The Yali Reservoir in Central Viet Nam is located in both Kom Tum and Gia Lai provinces, along the Sesan River, a sub-basin of the Mekong River basin. The Yali Falls Dam itself is approximately 70 kilometers upstream of the border with Cambodia.

Water allocation decisions in these two provinces are currently made independently from one another. As a result, each provincial authority prepares and adopts industrial sector master plans as well as socio-economic development plans for their respective provinces without assessing the impacts of these plans on water demand in their own province, and without knowledge of the impacts of the other province’s water demand. Planning is thus undertaken in each province without knowledge of whether or not there will in fact be enough water in the sub-basin to support the implementation of both sets of plans.

Due in large part to the region’s relative water abundance, this approach has not yet encountered very significant difficulties. However, moving to a context of increasing water scarcity (as illustrated by the 1 in 100 year drought experienced in the Yali Reservoir region in 2009-2010), decision-makers have recognized that the availability of water in the sub-basin may in fact become a constraining factor to the development of the region. There is, therefore, an urgent need to account for the impacts of socio-economic development plans on water demand.

Contributing to this initiative, a project team lead by Viet Nam’s Central Institute for Economic Management (CIEM) developed a methodological approach as well as an Excel-based software to account for the impacts of sector master plans and socio-economic development plans on water demand in the Sesan River sub-basin. The project focused on the area upstream of the Yali Reservoir in the Kom Tum and Gia Lai provinces.

Water from Yali Reservoir provides numerous services to the surrounding provinces, all of which needed to be accounted for in this assessment. The methodology uses standard water consumption coefficients in the domestic sector (with different coefficients applied to rural and urban households), agriculture (with crop specific water requirements applied to rice, corn, sugarcane, pepper, coffee, tea, cashewnut, rubber and cassava as well as for cattle, pig, and poultry production), and industrial sectors (handicraft and industrial zones), including hydropower production. In addition, different water coefficients were use for summer and winter crops in the agriculture sector. Sectors development master plans as well socio-economic development plans (which include population as well as gross domestic product projections) were then transformed into forecasted water demand.

Using existing development plans, it was shown in the course of this activity that water demand for Gia Lai province could increase by 17% by 2020 and 20% by 2030 compared with to the level of the year 2020. Similarly, water demand in Kon Tum province could by 63% and 78% respectively over the same period. If the sub-basin were to once again experience water scarcity as severely as experienced in 2009-2010, it is clear that such water demand could not be easily fulfilled.

This exercise has thus clearly highlighted to policy-makers and sector managers in both provinces that:

  1. Development plans can be and should be transformed into water demand projections; and
  2. There is a strong need for the coordination of water management across provinces of the sub-basin.

It is hoped that the software platform developed by the project team will continue to be updated with new information as sector master plans and socio-economic development plans are adopted.