From the perspective of natural water retention measures (NWRM), reconnection is the process of improving hydrological connection in the landscape, both through linking water bodies and through improving the connectivity between rivers and their adjacent floodplains. Reconnection can make use of historical and currently water channels to restore previously existing hydrological connectivity and functioning.

Afforestation of reservoir catchments can have multiple benefits. It can reduce sediment inputs from the catchment, lengthening the life of the reservoir, and may also have beneficial effects on water quality in some cases when peatlands are afforested. Afforestation can reduce peak flows and help to maintain base flows. The benefits of afforestation must be balanced against the potential for increased evapotranspiration from a rapidly growing forest.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission

Those expenditures that, once committed, cannot be (easily) recovered. These costs arise because some activities require specialized assets that cannot be readily diverted to other uses.

Shallow, broad and vegetated channels designed to store and/or convey runoff.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission

Sustainable Urban Drainage Systems (or SUDS) are a sequence of water management practices, green infrastructures and measures designed to drain surface water in a manner that mimics the natural hydrologic cycle and will provide a more sustainable approach to rainwater management than what has been the conventional grey infrastructure practice of routing run-off through a pipe to a receiving watercourse.

The cost linked the economic or relative scarcity of water once it is used.

Urban planning that incorporates trees can have multiple benefits. Trees in urban areas have multiple benefits including increased infiltration and other benefits including shade and amenity value.
- Elaborated by NWRM project experts, validated by th European Commission

Temporary streams are of particular importance when it comes to water storage and time retention especially in flash flood prone areas. Some measures can be directly implemented in order to ensure their proper functioning.
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission

Small-scale depressions used for storage and infiltration, typically at a property-level and close to buildings (e.g. to infiltrate roof drainage at a property level).
- Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission

Nitrate, NO-3, is the main nitrogen containing anion occurring in the soil. It is very soluble and moves freely in water through the soil profile. Nitrate in water is a pollutant above certain concentrations and can be a danger to human health. The main source of nitrate in water is agriculture although sewage discharges can also be an important factor.