Fergana Valley has formed under conjunction of rivers Naryn and Karadarya, which flow into valley in its beginning on the east and create Syrdarya River. Significant part of Syrdarya River tributaries and small rivers (says) - above thirty - currently are not reaching Syrdarya River and its main tributaries, because their water is allocated for irrigation. The largest mountain rivers are the following one: Padshaata, Gavasay, Kasansay, Karaungur, Kugart, Ak-Bura, Aravansay, Isfayramsay, Shakhimardan, Sokh, Isfara, Khojabakirgan and others flowing from Fergana and Turkestan ranges.

Syrdarya River forms about 70% of total flow of Fergana Valley water resources, the rest rivers and says form flow within 30%. Surface water inflow to Fergana Valley from flow formation zone constitutes basic amount of Syrdarya River basin water resources.

Table 1. Syrdarya River surface flow and Fergana Valley share in total flow formation (km3/year)

Nevertheless Fergana Valley never could use this flow, because river and downstream lands had own share of total flow. Maximal total valley consumption was 18.8 bln. m³ including irreversible 8.4 km³.

Fergana Valley water sources character feature  is that they are mainly transboundary between countries and oblasts and crossing states borders supply with water several administrative oblasts of each state: Naryn River - Fergana and Namangan oblasts, Karadarya River - Andijan, Jalalabad, and Osh oblasts, Syrdarya River - Fergana, Namangan, and Sogd oblasts.

Majority of small rivers is transboundary and provides water delivery to irrigated lands and several oblasts (rayons) of several states.

Data on water diversions and water supply volumes from water sources over Fergana Valley states are given in table 2 on 2000. It shows that:

·         total water diversion to valley area is 14565,9 mln. m³;

·         from pointed volume Uzbekistan share is 69,7 %, Kyrgyzstan – 18,4 % and Tajikistan – 11,8 %.

Table 2. Total volume of actual water diversion, water supply and water disposal in general over Fergana Valley and specific states at level 2000.

Main canals crossing Fergana Valley area are interstate and regional:

·        Big Fergana canal (BFC) delivers water to irrigated lands of Fergana, Namangan and Andijan oblasts of Uzbekistan and Sogd oblast of Tajikistan;

·         Big Andijan Canal (BAC) provides water delivery on territory of Fergana, Namangan and Andijan oblasts of Uzbekistan;

·         South Fergana Canal (SFC) supplies with water irrigated lands of Fergana and Andijan oblasts of Uzbekistan;

·         North Fergana Canal (NFC) delivers water to irrigated lands of Namangan oblast of Uzbekistan and Sogd oblast of Tajikistan;

·         Big Namangan Canal (BNC) provides water supply to irrigated lands of Namangan oblast of Uzbekistan and Djalalabad oblast of Kyrgyzstan.

Water volumes delivered by main canals to oblasts of some states over Fergana Valley provides with water their irrigated lands unevenly.

In table 1.7 data characterizing water diversion and supply volumes are given over above pointed canals within states and oblasts:

·        BFC provides water allocation between Uzbekistan and Tajikistan in proportion 90,5 % - on the first and 9,5 % - on the second;

·        BAC and SFC totally supply with water in amount 100 % oblasts of Uzbekistan;

·        NFC allocates water in proportion 92,2 % for Uzbekistan (Namangan oblast) and 7,2 % for Tajikistan (Sogd oblast).