Ecological and hydrological problems of water reservoirs on rivers of the Black Sea coast in the context of the increasing air temperature and emissions of greenhouse gases, the melting of glaciers, and the occurrence of floods and forest fires have been analysed in the given article. The article presents the results of field and theoretical studies of sedimentation processes in the large water reservoirs of Georgia focusing on their morphometric conditions during the warming period.

A groyne is a shore protection structure built perpendicular to the shoreline of the coast (or river), over the beach and into the shoreface (the area between the nearshore region and the inner continental shelf), to reduce longshore drift and trap sediments. A groyne field or system is a series of groynes acting together to protect a beach. Concret is often used as construction material. On the basis of analysis of wave suppression efficiency and stability on the slope of more than one hundred existing shaped massives the new type of coast protecting reinforced concrete blocks – so called “Hexablock” (“Hexablock” was called because of its 6 facets) characterized with higher wave suppression properties, interlocking capacity, stability on the slope and longer life time is proposed.