THE NEVA PROJECT: SITE 3

Geography of the Izhora basin

The small Izhora River joins the Neva from the south, 34 km. from the mouth of the Neva. The ancient settlement of Ust-Izhora (“Mouth of the Izhora”) occupies the high left bank of the Izhora overlooking the conjunction of the two rivers. On the right bank of the Izhora, somewhat upstream, stands the town of Kolpino, an old settlement that now serves as an administrative center of one suburban district of St.-Petersburg.
The river Izhora originates from a spring in the village of Skvoritsy, 11 km. northwest of the town of Gatchina. Like the Neva, it is a short river, measuring 76 km. in total length.
The Izhora watershed is about 81 km. in length, an average of 16 km. in width, with a total drainage area of 1260 sq. km. (see table). Most of this area is on the Izhorsky Plateau, a relatively flat terrain with occasional hills no more than 5 or 10 m. high. Administratively, the watershed impinges on three districts of the Leningrad Region and the Kolpinsky district of. St. Petersburg.
There are 495 rivers and other waterways in the hydrographic system of the Izhora, 489 of which are less than 10 km. in length. The total length of all rivers in the Izhora system is 646 km.

The Izhora watershed contains no lakes, but there are some artificial reservoirs in the eastern part of it. The most significant of these is the Kolpinsky reservoir (volume is 3.6 million cubic meters, length=6.5 km, width=200-300 m, depth from 1 up to 8 m).
Upstream, the Izhora mainly draws its water from natural springs. In its middle reaches, the river relies less on groundwater resources and more on snow melt and, to a lesser degree, rain water. The river has a sustainable underground water supply in both summer and winter, so it never dries up or freezes through.
The average water flow in the Izhora is 0,67 m3/sec, with a range from 0.025 to 2.98 m3/sec, and the mean discharge of its water into the Neva is 4.76 m3/sec. The average slope of the river bed is small (1.23 %). The lowest part of the Izhora, near its mouth, is completely influenced by fluctuations in the Neva’s water level.

Ust-Izhora geography

References and links

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