Levelling longitudinal barriers allows re-establishing fluvial dynamics and ecological continuity. The aim is to restore the slope and longitudinal profile of the river, to restore natural water flows, to allow for the solid transport (sediment) to take place, toﾠ diversify flows (depth, substrate, speed), diversify habitats and related flora and fauna.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
Basins and ponds store surface run-off.ﾠ Detention basins are free from water in dry weather flow conditions but ponds (e.g., retention ponds, flood storage reservoirs, shallow impoundments) contain water in dry weather, and are designed to hold more when it rains.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission
AGR stores large quantities of water in underground aquifers to increase the quantity of groundwater in times of shortage.ﾠ It results in a lowering of run-off from surrounding land, and in an enhanced natural condition of aquifers and water availability.ﾠ The natural cleaning process of water percolating through the soils when entering the AGR improves water quality. Mechanisms used to undertake the recharge should be highlighted. In this respect one can envisage:(i) surface structures to facilitate/augment recharge (such as soakways and infiltration basins);(ii) subsurface indirect recharge - artificial recharge is undertaken through wells drilled within the unsaturated zone;(iii) subsurface direct recharge - artificial recharge is undertaken through wells reaching the saturated zone. The regulatory approach to be adopted for each of the above three mechanisms could differ considerably, due to the fact that the level of natural protection to groundwater is vastly different for each of the mechanisms
To ease the overall functioning of the river, some hydrographical network elements could be reconnected, including the so-called hydraulic annexes. This will allow for improvement of lateral connectivity, diversifying flows and habitats, but also cleaning the secondary arms that play a key role for retention in high water periods.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission