PO4 - Improving chemical status and priority substances

Permeable paving is designed to allow rainwater to infiltrate through the surface, either into underlying layers (soils and aquifers), or be stored below ground and released at a controlled rate to surface water. Permeable paving is used as a general term, but two types can be distinguished:

-       Porous pavements, where water is infiltrated across the entire surface (e.g. reinforced grass or gravel, or...

Riverbank represents both natural and man-made features following the river flow. In the past, lots ofmany artificial banks were built with concrete or other types of retaining walls, thus restricting the natural movements of rivers, leading to river degradation, increased water flow, increased erosion and reduced biodiversity. 

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...

Swales are broad, shallow, linear vegetated channels which can store or convey surface water (reducing the rate and volume of runoff) and remove pollutants. They can be used as conveyance features to pass the runoff to the next stage of the SuDS treatment train and can be designed to promote infiltration where soil and groundwater conditions...

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...

Streambed (or riverbed) represents the bottom of the river, including each bank. In the past, riverbeds have been artificially modified with concrete or big boulders, altering flows and reducing habitat for wildlife and vegetation diversity. The changes were aimed at preventing flood or supporting changes of agricultural practices for example. This has led to more...

Soakaways are buried chambers that store surface water and allow it to percolate into the ground. They are typically square or circular excavations either filled with rubble or lined with brickwork, pre-cast concrete or polyethylene rings/perforated storage structures surrounded by granular backfill. The supporting structure and backfill...

Groundwater is the part of infiltrated water which composes the water resource for population and human activities.  Previous modifications of the landscape have reduced the infiltration capacity of many European soils, thereby limiting the rate at which precipitation is able to infiltrate and recharge groundwater aquifers. Restoration of natural infiltration to groundwater enables a lowering of run-off from surrounding land, and...

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...

Green roofs are multi-layered systems that cover the roof of a building with vegetation and/or green landscaping over a drainage layer. There are two types of green roof: 

• Extensive green roofs cover...