Blue space

Lakes, ponds, and reservoirs


Main purpose:

Water retention

Services delivered:
Wellbeing, Heat mitigation, Water flow management

Position of NBS in the city:
Naturally occurring or man-made


Lakes, ponds, and reservoirs are mostly stagnant waters with a very slow flow. This group contains mostly freshwater with few exceptions of mixed water and saltwater waterbodies. These waterbodies offer a rich habitat for various species and freshwater for consumption.

In cities around the globe, they reduce city temperatures, serve as recreational space, fishing grounds, and as a water management hotspot while preventing floods and purifying water. Stagnant water bodies in cities are especially sensitive to contamination from various sources. 

Relevant facts

The figures that speak change!


Freshwater systems are rich ecosystems with nearly 6% of described species (i.e., 100,000 species).


In the hottest months from May to October, water bodies can have a cooling effect of an average of 2.5 Celsius.