It does not really look like one, but Bukhtarminsk Reservoir (Bukhtarminskoye vodokhranilishchye) is not only the largest reservoir in Kazakhstan but among the largest of its kind in the world. Only a small slice of land was lost when the Irtysh was diverted to this water basin, 340 kilometres long, 25 kilometres wide and up to 68 metres deep. A valley with rocky subsoil was filled up, resulting in a clean, natural-looking lake.
Formed by damming the Irtysh River to the east of Ust Kamenogorsk, the long Z-shaped Bukhtarma Reservoir, constructed in the 1960s, has a total length of around 600km, and a surface area of 5,490km2, making it the fifth-largest reservoir in the world by surface area. A multi-purpose reservoir, it supports a power plant of 675MW, has a storage capacity of 49.8km3, and accounts for a quarter of Kazakhstan's total freshwater fish production. Sturgeon, sterlet and carp are among the species found here. The local authorities are trying to promote the development of fishing tourism, particularly around Lake Zaisan, a large freshwater lake in the eastern part of the region, fed by the waters of the Black Irtysh from China, and in turn feeding into the main Irtysh. Lake Zaisan found itself incorporated into the Bukhtarma Reservoir, as the southeasternmost component of that body of water, its level rising some 6m in the process.
For the citizens of Ust-Kamenogorsk, the construction of the Bukhtarma Reservoir meant the possibility of lakeside beach resorts within reach of the city. There are several holiday bases, most of which are open only during the summer season, offering sand and a range of watersports.
Popular places include the bays of Ayuda and Altai, the more remote location where the Bukhtarma River flows into the reservoir, and most of all Blue Bay (Goluboy zaliv). This is on the northern shore of the lake not far from the road to Zyryanovsk, just beyond the hamlet of Bukhtarma, where there are small cottages and resthomes for rent. Booking through a travel agency is recommended, since Blue Bay is in great demand during the holiday season, although off-season there is often nobody there at all. Temperatures are good for swimming until early September. Buses from Oskemen to Blue Bay are cheap and take two hours, but a more enjoyable way to get there is to take to the river on a raketa-a reconstructed Soviet hydrofoil, which in summer shuttles between Oskemen and the reservoir. They shoot upstream to the lock at Serebryanka, where the dam is bypassed.
A water-borne experience can be had by crossing on one of the boats that ferry people and vehicles from shore to shore, reducing travel time between Oskemen and the far northeast reaches of the region. In most places the western shore is flat and bare, and to the south of the Kurshum ferry there are even desert dunes. The eastern shore is lined with hills, and on the northernmost bays the forests reach down to the shore, offering a wonderful contrast with the clear, blue water in autumn. One can drive around the entire lake, and the road often remains close to the water along the east shore, before heading into hills filled with groves of silver birch. In spring and summer the road is lined with bright-yellow flowers, the rolling green hills punctuated with ploughed fields of black earth, showing how mineral-rich the soil is. Villages in the Altai foothills are filled with modest but well-built houses, with steep-sided roofs (to shed the heavy falls of snow that shroud the land in winter) and bright-blue window shutters-a common theme throughout Kazakhstan, ut particularly attractive here, surrounded by such a vivid display of nature's colours. The road heads east away from the reservoir and eventually crosses the hilly heights, revealing a sweeping panorama of the broad Narym River Valley and the line of 3,000-4,500 metre Altai peaks that hide Markakol Lake and the Chinese border beyond.