PO7 - Prevent surface water status deterioration

Headwater catchments are the source areas of rivers and streams and are critical for maintaining the structure, function, productivity and complexity of downstream ecosystems. They are vital to hydrologic cycle as they are one of the main areas where precipitation contributes to surface and groundwater. Headwaters are typically...

Seasonal streams or intermittent rivers are rivers for which surface water ceases to flow at some point in space and time. They comprise a large proportion of the global river network and are characterised by dynamic exchanges between terrestrial and aquatic habitats. These habitats support aquatic, semi-aquatic, and terrestrial biota. Seasonal streams provide essential ecosystem services to society, including flood control and irrigation....

Ongoing climate change affects lake water quality through several mechanisms, including (1) changes in external and internal nutrient loads, (2) increased frequency of extreme events such as hurricanes, (3) temperature-induced changes in biota and biotic interactions, and (4) fluctuations in water levels.
Lakes function as important water retention systems, capable of storing water for flood control and providing water for multiple uses...

Filter strips are uniformly graded, gently sloping, vegetated strips of land that provide opportunities for slow conveyance and (commonly) infiltration. They are designed to accept runoff as overland sheet flow from upstream development and often lie between a hard-surfaced area and a receiving stream, surface water collection, treatment or disposal system. 

Filter strips are generally planted with grass or other dense vegetation...

Retention ponds are ponds or pools designed with additional storage capacity to attenuate surface runoff during rainfall events.  They consist of a permanent pond area with landscaped banks and surroundings to provide additional storage capacity during rainfall events.  They are created by using an existing natural depression, by excavating a new depression, or by constructing embankments.  Existing natural...

Dams and other transversal barriers are obstacles crossing the river section and causing discontinuities for sediment and fauna. Removing them consists in destroying all the obstacles, restoring the slope and the longitudinal profile of the river, therefore allowing re-establishment of fluvial dynamics, as well as sedimentary and ecological...

A riverbank protection is an inert or living construction providing bank fixation but also an obstacle for the lateral connection of the river. Eliminating it consists in removing some parts of the bank protection, especially the inert one, in order to enhance lateral connections of the river, diversify flows (depth, substrate, and speed) and habitats, but also cap floods in the mainstream. It is a prerequisite for many other measures like re...

A river meander is a U-form taken by the river, allowing it to decrease water velocity. In the past, rivers have been straightened by cutting off meanders. Many rivers in northern and Western Europe have been straightened and channelized to, for example, facilitate log floating and/or speed up the drainage of water and control/limit the river bed movements. Channelizing was also a way to gain land for cultivation. River re-meandering consists...

An oxbow lake is an ancient meander that was cut off from the river, thus creating a small lake with a U form. Reconnecting it with the river consists in removing terrestrial lands between both water bodies, therefore favouring the overall functioning of the river by restoring lateral connectivity, diversifying flows and cleaning the river section of the present oxbow for a better water retention during floods. 

Recent literature...

A floodplain is the area bordering a river that naturally provides space for the retention of flood and rainwater.  Because of regular flooding, floodplain soils are generally very fertile and they have often been dried-out to be used as agricultural land. Floodplains in many places have also been separated from the river by dikes, berms or other structures designed to control the flow of the...