Disturbances of the downstream revetment of the votkinsk hydroelectric station that occurred during operation

Conclusions

• 1. Operation of the structures of the Votkinsk hydrostation occurs under condition different from those proposed in the design: there is no backwater from the reservoir of the Lower Kama hydrostation, as a consequence of transformation of the Kama channel the lower pool levels are 1 m below the design levels.

• 2. As the experience of operating the Votkinsk hydrostation with considerable daily variations of the load and, accordingly, with considerable fluctuations of the lower pool level shows, the unprotected stretches in the lower pool in the zone of variable levels are subjected to erosion. They have to be protected during operation. The earlier works on revetting the eroded stretches are performed, the smaller the expenditures they require.

• 3. At hydrostations operating under conditions analogous to those of the Votkinsk hydrostation it is necessary to conduct hydraulic studies in the lower pool and to measure the flow velocities for the purpose of eliminating erosion as well as for the correct selection of the variant of revetting the downstream stretches.

• 4. For further safe operation of the Votkinsk hydrostation it is necessary to carry out in 1996–1998 revetting of the downstream slope of earth dam No. 1 and works on preventing scour behind the toe wall of the apron of the hydrostation in accordance with the design of Lengidroproekt.