Pre-reservoirs: A Sustainable Solution For Eroding Beaches/deltas Of Dammed Rivers
Free (open access)
179 - 188
A. Toumazis, K. Kyrou, N. Iacovou, J. Sophos, S. Zervos & G. Anastasakis
Dams have as their main objective the storage of storm water. The arrest of sediments in the reservoirs is an indirect impact of the water storage. The trapping of sediments in the reservoirs reduces the storage capacity of the dam and arrests the sediment supply to the river mouth/delta. This starvation of sediment supply to the coastal environment results in the termination of the development of the river delta. Depending on the coastal hydrodynamics, recess of the delta and erosion of the coastline are initiated. This problem is acute in Cyprus, where almost all rivers have been dammed and erosion of the beaches is experienced in numerous areas. A sustainable solution has been developed which addresses the restoration of the sediment cycle and at the same time it minimises the risk of pollution to the water stored in the reservoir and of pollution of the sediments deposited on the beach. The construction of a small dam, called pre-reservoir, within the main dam reservoir causes the temporary storage of the impounding water and the deposition of sediments within its reservoir. The stored water is allowed to drain to the main reservoir, if the water is of acceptable quality, whilst the collected sediments are evacuated once a year. After segregation, suitable sediments are transported to the beach. This system achieves sustainable management of sediments currently trapped in dams, restoration of sediment supply to the coastal environment and assurance of water quality of the dams. Keywords: dams, sediments, erosion, river delta, coastal management, Cyprus, pre-reservoir, water quality.
dams, sediments, erosion, river delta, coastal management, Cyprus, pre-reservoir, water quality.