the purpose of large-scale farmland irrigation in the downstream Uzbekistan, Turkmenistan, and Kazakhstan. Farmland irrigation in downstream countries highly depends on water reservoirs in the upstream Kyrgyzstan and Tajikistan. Although the upstream Kyrgyzstan and Tajikistan have an energy shortage, they can import petroleum, natural gas, and coal for heating from Uzbekistan, Kazakhstan, and Russia.

### Division of labor was determined and centralized management of water resources was implemented {#Sec8}

During the early stage of the former Soviet Union, the principle of "division of labor" was set up in Central Asia, striving to develop Central Asia into a single agricultural production base. For example, Uzbekistan and Kazakhstan are major cotton production bases, whereas Kyrgyzstan is an agricultural production base and the major power generation base. Although such division of labor causedAsian countries became independent, the fiercest water fight in Central Asia was between upstream and downstream countries of the Aral Sea. Countries began to pay close attention to the allocation of water resources of the Amu Darya and the Syr Darya and corresponding tributaries. Meanwhile, the intertwined energy and water problems complicated the transnational issues in Central Asia.

### The water resource allocation problem was not solved effectively due to the absence of an agreed instruction center {#Sec10}

After the collapse of the Soviet Union, although the previous water conservancy facilities and water allocation system were retained, Central Asian countries have gained sovereignty and have their respective national interests. Resources (including water recourses) became their own properties. Currently, the combination of Soviet central planning and fractious independent states has created