That's because the reservoir closed in 1993 after being a water source for the city since 1863, and the water has essentially been stagnating since then.
This deep water stagnates and slowly moves south.
That may mean that the water is stagnating in those areas, allowing the bacteria to grow.
Non-revenue water stagnated at an estimated 45-50%.
The water stagnates and ruins the stones.
When water stagnate in late summer hydrogen sulfide and oxygen shortage occurs in lake sediments.
In rainy season water stagnates inside the shrine, which is cleared manually.
Helicopters surveyed the area for stagnant family swimming pools and officials offered to haul away used tires, for example, where water can pool and stagnate.
Between floods, the water in the lagoon stagnates.
Drainage: In soils of bad drainage the water delivered through rain or irrigation may pool and stagnate.