Geography of Kazakhstan the water in Kazakhstan is polluted by industrial effluents, pesticide and fertilizer residue, and, in some places, radioactive elements. The most visible damage has been to the Aral Sea, which as recently as the 1970s was larger than any of the Great Lakes of North America save Lake Superior. The sea began to shrink rapidly when sharply increased irrigation and other demands on the only significant tributaries, the Syr Darya and the Amu Darya (the latter reaching the Aral from neighboring Uzbekistan), all but eliminated inflow. During the Soviet Era, Kazakhstan received water from Tajikistan and Kyrgyzstan, and Uzbekistan, Turkmenistan,
Rivers of New Zealand scenic rivers. Over half of the electricity generated in New Zealand is hydroelectric power. Hydroelectric power stations have been constructed on many rivers which dam the river completely, or channel a portion of the water through the power station. There is large hydroelectric power scheme in the North Island and in the South Island where water is diverted between rivers using a system of canals that is used to maximise the electricity generation. River conservation is threatened by pollution inflows from point and non-point sources. In the past rivers had been used for pollution discharges from factories and municipal sewerage