Small retention is the ability to store water in small natural reservoirs (ponds, oxbow lakes) and artificial reservoirs (fishponds, excavations, small dam reservoirs) with capacities of several thousand cubic meters, the storage of water within the river network or drainage ditches, and the increase of the soil’s water capacity through agrotechnical measures.
The primary role of small retention is not to store water resources directly suitable for economic use, but rather to change habitat moisture conditions, raise the groundwater level, and modify the microclimate.
An increase in catchment surface retention—mainly of open waters and the river or drainage ditch network—can be achieved through:
- restoration of small dam reservoirs, mid-forest and mid-field ponds, and stream networks,
- construction of new reservoirs of various types,
- increasing the retention capacity of existing reservoirs through additional damming,
- construction of low weirs on natural watercourses, canals, and ditches,
- protection of wetlands, peat bogs, and cessation of drainage of these areas.
Within the framework of small retention, the primary damming structures used on rivers and drainage ditches are sluices, weirs, and steps. In past engineering practice, these damming structures were mainly made of wood or concrete; today, they can also be successfully built from plastics.
