In summer the “upper lake” on the Kame-jima, “Turtle island”, gives us a lot of joy. Every day, we see a diversity of birds that come to drink and bath in this small pond.
The water in the “upper lake” (right) gets continuously replenished and refreshed by a small fountain-pump that gets the water from the “lower lake” (left) that serves as a reservoir.
The construction is based on the overflow principle. During frost periods this principle can cause problems and empty the reservoir is a few hours.
Because we want to offer the birds the possibility to drink and even bath specifically in these difficult periods we have found a solution to this problem. I pull the hose that replenishes the upper-lake, out of the hole and place it under it. We let the pump run and now the flowing water prevents it from freezing and also keeps (part of) the “lower lake” open, thus giving water to the birds.
Here the prove that the birds love this and the frequently return to drink and even bath, in particular during severe winter periods with sharp frost.
For additional construction details see in Turtle Island lakes construction in Constructing the Main Tsukubai and Turtle Island lakes.
As a reference this bottom photo shows some bathing birds in summer.