ABSTRACT
Construction of underground dams and reservoirs in karst is relatively new in dam engineering and engineering karstology. Experiments, design and construction of underground dams started in the second half of the 20th century. Every karst aquifer will have distinctive hydrogeological features, so that a model concept for underground damming must consider a significant number of variables: the lithology, geological structure, the base of karstification, the location of base flow conduits, the number of discharge points, their discharge capacity, hydraulic characteristics such as volumes of sedimentation, possible connections with adjacent karst aquifers, the physical accessibility of large karst channels, possible influence on upstream areas (e.g., inadvertent back-flooding), the influence on local seismic balances, on water quality, on the ecosystem, plus many secondary influences.
In the Chinese karst from the late 1950s until the beginning of 21st century many underground dams and reservoirs with storage capacities from several hundred thousand to several million cubic meters were constructed.
Experience with underground dams in China and Europe is positive and due to less and less locations for surface dams the more attention should be focused to underground storage structures.
