Natural bank stabilisation

Definition

In the past, various activities were undertaken to straighten rivers, such as the stabilisation of river banks with concrete or other types of retention walls.ᅠ Such actions limited riversメ natural movements, leading to degradation of the river, increased water flow, increased erosion and decreased biodiversity.ᅠ Natural bank stabilisation reverses such activities, allowing rivers to move more freely.ᅠ Where bank stabilisation is nevertheless necessary, such as in residential areas, natural materials such as roots or gravel can be used.ᅠ Natural materials are preferable as they allow water to infiltrate into the bank.ᅠ They also provide better living conditions for aquatic fauna.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission

Hydraulic annexes

Definition

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

Levelling of dams/ longitudinal barriers

Definition

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

Artificial groundwater recharge (AGR)

Definition

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

Bank

Definition

The sloping side of any hollow in the ground, especially when bordering a river. (Source: CED)

Gabion

Definition

A gabion (from Italian gabbione meaning "big cage"; from Italian gabbia and Latin cavea meaning "cage") is a cage, cylinder, or box filled with rocks, concrete, or sometimes sand and soil for use in civil engineering, road building, and military applications.

Lake restoration

Definition

Lakes are by definition water retention facilities; they store water (for flood control) and provide water for many purposes such as water supply, irrigation, fisheries, tourism, etc.ᅠ In addition, they serve as sinks for carbon storage and provide important habitats for numerous species of plants and animals, including waders.ᅠ In the past, lakes have sometimes been drained to free the land for agriculture purposes, or have simply not been maintained and have silted up.ᅠ Restoring lakes is re-introducing them where they have been in former times or revitalising them.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission

Biophysical parameter

Definition

A biophysical parameter is a measurable characteristic that can help in defining a particular system. It can cover individual substances, groups of substances or be defined by its measurement method like turbidity or the mesurement of oxygen consumption like BOD5 or COD. It is generally expressed by a value and its unit.

Basins and ponds

Definition

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

Elimination of riverbank protection

Definition

The suppression of lateral constraints consists in removing some bank protection in order to enhance lateral connection of the river, diversifying flows (depth, substrate, speed), diversify habitats but also capping floods in the mainstream.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission